AI and ML have the spotlight right now in science, and the conference promises to be the first of many, says Feryal Özel, Professor and Chair of the School of Physics. 

"We were delighted to host the AI/ML in Physics conference and see the exciting rapid developments in this field,” Özel says. “The conference was a prominent launching point for the new AI/ML initiative we are starting in the School of Physics."​ 

That initiative includes hiring two tenure-track faculty members, who will benefit from substantial expertise and resources in artificial intelligence and machine learning that already exist in the Colleges of Sciences, Engineering, and Computing.

The conference attendees heard from colleagues about how the technologies were helping with research involving exoplanet searches, plasma physics experiments, and culling through terabytes of data. They also learned that a rough search of keyword titles by Andreas Berlind, director of the National Science Foundation’s Division of Astronomical Sciences, showed that about a fifth of all current NSF grant proposals include components around artificial intelligence and machine learning.

“That’s a lot,” Berlind told the audience. “It’s doubled in the last four years. It’s rapidly increasing.”

Berlind was one of three program officers from the NSF and NASA invited to the conference to give presentations on the funding landscape for AI/ML research in the physical sciences. 

“It’s tool development, the oldest story in human history,” said Germano Iannacchione, director of the NSF’s Division of Materials Research, who added that AI/ML tools “help us navigate very complex spaces — to augment and enhance our reasoning capabilities, and our pattern recognition capabilities.”

That sentiment was echoed by Dimitrios Psaltis, School of Physics professor and a co-organizer of the conference. 

“They usually say if you have a hammer, you see everything as a nail,” Psaltis said. “Just because we have a tool doesn't mean we're going to solve all the problems. So we're in the exploratory phase because we don't know yet which problems in physics machine learning will help us solve. Clearly it will help us solve some problems, because it's a brand new tool, and there are other instances when it will make zero contribution. And until we find out what those problems are, we're going to just explore everything.”

That means trying to find out if there is a place for the technologies in classical and modern physics, quantum mechanics, thermodynamics, optics, geophysics, cosmology, particle physics, and astrophysics, to name just a few branches of study.

Sanaz Vahidinia of NASA’s Astronomy and Astrophysics Research Grants told the attendees that her division was an early and enthusiastic adopter of AI and machine learning. She listed examples of the technologies assisting with gamma-ray astronomy and analyzing data from the Hubble and Kepler space telescopes. “AI and deep learning were very good at identifying patterns in Kepler data,” Vahidinia said. 

Some of the physicist presentations at the conference showed pattern recognition capabilities and other features for AI and ML: 

• Cassandra Hall, assistant professor of Computational Astrophysics at the University of Georgia, illustrated how machine learning helped in the search for hidden forming exoplanets. 
• Christopher J. Rozell, Julian T. Hightower Chair and Professor in the School of Electrical and Computer Engineering, spoke of his experiments using “explainable AI” (AI that conveys in human terms how it reaches its decisions) to track depression recovery with deep brain stimulation.
• Paulo Alves, assistant professor of physics at UCLA College of Physical Sciences Space Institute, presented on AI/ML as tools of scientific discovery in plasma physics.

Alves’s presentation inspired another physicist attending the conference, Psaltis said. “One of our local colleagues, who's doing magnetic materials research, said, ‘Hey, I can apply the exact same thing in my field,’ which he had never thought about before. So we not only have cross-fertilization (of ideas) at the conference, but we’re also learning what works and what doesn't.”

More information on funding and grants at the National Science Foundation can be found here. Information on NASA grants is found here. 

The briefcase-sized Lunar Flashlight will be monitored and controlled over the next several months by a team of graduate and undergraduate students in Georgia Tech’s School of Aerospace Engineering. The team will keep the spacecraft on track and capture the data it gathers to be studied by the Lunar Flashlight Science team.

Watch a video on the Lunar Flashlight mission on YouTube

The spacecraft launched at 2:38 a.m. December 11 on a SpaceX Falcon 9 rocket that also carried a Japanese-built lunar lander and a United Arab Emirates rover. Shortly after launch, Lunar Flashlight separated from the Falcon 9 to begin an approximately three-month journey that will carry it into a fuel-conserving orbital trajectory 42,000 miles beyond the moon. Gravity from the moon, Earth, and Sun will ultimately bring it into a path that will come within nine miles of the lunar surface.

Once in its science orbit around the moon, Lunar Flashlight will shine four lasers into perpetually-dark craters near the lunar South Pole. Each laser operates at a slightly different frequency, and the reflected light acts like a spectral fingerprint that identifies the material that it illuminated. If ice is there, the near-infrared light from the lasers will be absorbed by the water. If the light reflects back to the Lunar Flashlight, that will indicate the absence of ice. Data from the spacecraft will be radioed to NASA’s Deep Space Network and received by student controllers on the Georgia Tech campus, who will then share it with the Lunar Flashlight Science Team.

Surface water ice may be a treasure trove of water from different sources such as volcanic outgassing and meteorite impact, so knowing where it resides will help point future assets to examine it at the surface. If sufficient amounts exist, the precious liquid may be used to help meet the drinking water needs of future lunar colonies. Water molecules from potential ice reservoirs in the South Pole craters could also be split to provide a source of oxygen for breathing and hydrogen for rocket fuel.

Big Capabilities in a Small Spacecraft

Despite its small size, Lunar Flashlight – which was designed by NASA’s Jet Propulsion Laboratory – has big capabilities. Lunar Flashlight carries a propulsion system that will be used to make mid-course corrections and allow the spacecraft to get into lunar orbit and accomplish its mission. Built at Georgia Tech’s School of Aerospace Engineering, the propulsion system uses a new monopropellant developed at the Air Force Research Laboratory to be more environmentally safe than earlier propellants.

“It’s a very capable spacecraft for sure,” said Jud Ready, a Georgia Tech Research Institute (GTRI) principal research engineer who served as principal investigator for the final assembly and testing of Lunar Flashlight at Georgia Tech. “Achieving lunar orbit insertion can be challenging for a conventional spacecraft, let alone a vehicle the size of a desktop computer.”

The solar-powered Lunar Flashlight is part of a new generation of small spacecraft with capabilities formerly seen only on larger vehicles. First used in low earth orbit, the smaller vehicles are now traveling to the moon, and potentially to other planets in the solar system.

“Space exploration was formerly the realm of major governments – the United States, Russia, China, Japan, and a few others,” said Ready. “Using smaller spacecraft like Lunar Flashlight means a lot more opportunity for this. There will likely be thousands of other small spacecraft launching behind us.”

A Learning Experience for GTRI and Georgia Tech

Final assembly of the Lunar Flashlight took place in a cleanroom in a GTRI building on the main Atlanta campus, where the laser system also was tested. Specialized equipment at GTRI’s Cobb County Research Facility tested the spacecraft’s radio equipment and simulated the stresses of launch. Thermal, vacuum, and other testing took place in Georgia Tech’s School of Aerospace Engineering.

For the faculty, staff, and students involved, Lunar Flashlight has provided a great learning experience.

“We learned how to apply NASA’s rigorous protocols to everything we did, protect the spacecraft from electrostatic discharge, schedule complex testing tasks, and utilize our student researchers who must also maintain their schoolwork and take exams,” Ready said. “There have been some real sacrifices by a lot of folks who worked long and odd hours.”

After completion of the final assembly and testing at Georgia Tech, Lunar Flashlight traveled to the Marshall Space Flight Center in Huntsville, Alabama, for fueling and additional testing. Finally, it made the trip to the Cape Canaveral Space Force Station in Florida for integration onto the SpaceX rocket.

Ready is hopeful that if Lunar Flashlight finds evidence of significant ice deposits on the moon’s South Pole, the precious water will help set the stage for creating a permanent human presence there.

“It’s really disappointing that we went to the moon in the 1970s, but didn’t stay there,” he said. “However, when you look at the big scheme of things, exploration is often measured in hundreds or even thousands of years. So, it’s not surprising that colonization of the moon would take longer than a few decades.”

Writer: John Toon (john.toon@gtri.gatech.edu).

GTRI Communications

Georgia Tech Research Institute

Atlanta, Georgia USA

About GTRI: The Georgia Tech Research Institute (GTRI) is the nonprofit, applied research division of the Georgia Institute of Technology (Georgia Tech). Founded in 1934 as the Engineering Experiment Station, GTRI has grown to more than 2,800 employees, supporting eight laboratories in over 20 locations around the country and performing more than $700 million of problem-solving research annually for government and industry. GTRI's renowned researchers combine science, engineering, economics, policy, and technical expertise to solve complex problems for the U.S. federal government, the state, and industry. For more information, please visit www.gtri.gatech.edu.

The development of hypersonic vehicles able to travel through the Earth’s atmosphere at Mach 5 or faster – five times the speed of sound – is attracting substantial new government and industry funding. But test facilities needed to evaluate thermodynamic, aerodynamic, acoustic, and other issues critical to operating in that harsh environment are limited, in high demand, and costly to use.

Georgia Tech researchers want to eliminate that roadblock by building hardened CubeSats that could use re-entry from space to generate the conditions needed to evaluate hypersonic technologies. The small satellites, with their key systems protected from the heat of re-entry, would be launched into the upper atmosphere from the International Space Station or a “rideshare” rocket to provide several minutes of testing at velocities of up to Mach 25.

“We are looking at the feasibility of building what would be an inexpensive flying wind tunnel,” said Krish Ahuja, Regents Professor of Aerospace Engineering and division chief for aerospace and acoustics in the Aerospace, Transportation, and Advanced Systems Laboratory of the Georgia Tech Research Institute (GTRI) and the project’s principal investigator. “We could gather pretty much any data that would be needed for hypersonic research and provide a new way to conduct studies that now can be quite difficult to do.”

Initial Study Suggests Developing 6U Vehicle

Based on a six-month feasibility study that included collaborators from Georgia Tech’s School of Aerospace Engineering and two private companies, Ahuja believes it would be worthwhile to pursue design of a 6U test vehicle to evaluate the concept. (A 6U CubeSat is about the size of the system unit of a desktop computer). If that proves promising, larger vehicles could be constructed with more capable instrumentation, guidance, and even propulsion.

The goal of the project’s first year is to understand what would be required to develop and launch the flying testbeds – and recover them after flight. Design and development of the new test vehicles must overcome significant challenges related to controlling the flight duration, speed, altitude, and orientation of the vehicle during data collection. Systems to communicate with the ground and track the vehicle’s trajectory must also be developed. Also, part of the first-year goal is creating a roadmap showing the development and test process.

“Ongoing work will include a ‘system-of-systems’ analysis of the concept to model its performance and interaction with other support systems to assess its capability to conduct scientific research,” Ahuja said. “Our initial calculations indicate that a 6U CubeSat could be hardened with a thermal protection system for hypersonic conditions to help conduct limited feasibility experiments. This will be a building block for future systems that would be larger and able to conduct the testing we envision.”

Initial testing is likely to involve free fall of the test vehicle, but subsequent tests would include control surfaces that would provide steering to prevent tumbling and other undesired effects. Multiple CubeSats could also be operated together.

Possible New Capabilities for Small Satellites

CubeSats, so-called because they are designed in standard cube sizes, aren’t normally designed to be recovered after a mission; when their work is done, they simply burn up in the atmosphere. Because Ahuja wants to study effects on materials and capture data from onboard instruments, the flying wind tunnel satellites will need to be recovered using parachutes that would drop them into a recovery zone, perhaps in the desert Southwest.

“Getting them down at the right location will require good guidance and control, good telemetry, and a propulsion system,” he said. “The challenge will be to make these very small and inexpensive. To get the information we need, we will have to bring the testbed safely to the ground.”

The high temperatures generated by re-entry into the Earth’s atmosphere could be useful for more than simulating hypersonic conditions. Ahuja believes the heat could be used to operate a proprietary device that could provide steering for the CubeSats, which normally don’t have propulsion systems.

Much of current research on hypersonic flight depends on data from computational fluid dynamics simulations, which need validation from testing. Beyond the information gained from the testbed, Ahuja believes the small spacecraft could make big contributions by providing a real-world anchor for the analysis tools that researchers are using for a variety of hypersonic vehicles.

A New Approach to Hypersonic Testing is Needed

Hypersonic testing is typically done in short-duration wind tunnels or high-temperature testbeds, meaning high-speed and high-temperature conditions are difficult to achieve simultaneously and at test durations relevant to hypersonic vehicles. In addition, there are few existing facilities where such testing can be done, and they are in high demand. The new testbed is expected to provide about three minutes of testing per flight.

Currently, there is a critical need to understand how much and what kind of thermal protection system is needed to protect hypersonic vehicles at high velocities where friction can produce temperatures of more than 4,000 degrees F. Additionally, there are questions about acoustic effects and how uneven heating will spread across a vehicle and potentially damage its structure.

“The airflow across a hypersonic vehicle can be both turbulent and laminar, different on different parts of the vehicle,” said Ahuja. “These wide variations of the flow properties can produce large variations in temperatures over the vehicle surface, which is highly undesirable with respect to the vehicle’s structural integrity. As such, we need to understand what is happening to the material as a result of temperature changes over time. This thermal loading cannot be studied in conventional wind tunnels, which normally offer fractions of seconds of run time at hypersonic conditions, because it takes a while for those conditions to become steady.”

Acoustic loading can also dramatically affect the structural integrity of a hypersonic vehicle, and that likewise requires time to evaluate. “Acoustic loading of the kind that could generate a crack in a structure that develops over time,” he said. “We could create and study these conditions with our flying testbed.”

Funding from GTRI’s Independent Research and Development (IRAD) program has supported the initiative so far, and by gathering enough data from the initial studies, Ahuja hopes to attract collaborators to help implement the new test approach.

“There is so much enthusiasm for this that I believe our chances of success are high,” he said. “By launching from another space system, we won’t have to worry about the initial launch propulsion. This could address a lot of challenges in conducting hypersonic research.”

Writer: John Toon (john.toon@gtri.gatech.edu).

GTRI Communications

Georgia Tech Research Institute

Atlanta, Georgia USA

About GTRI: The Georgia Tech Research Institute (GTRI) is the nonprofit, applied research division of the Georgia Institute of Technology (Georgia Tech). Founded in 1934 as the Engineering Experiment Station, GTRI has grown to more than 2,900 employees, supporting eight laboratories in over 20 locations around the country and performing more than $800 million of problem-solving research annually for government and industry. GTRI's renowned researchers combine science, engineering, economics, policy, and technical expertise to solve complex problems for the U.S. federal government, the state, and industry. For more information, please visit www.gtri.gatech.edu.

NASA plans to launch Lunar Flashlight, a small satellite (SmallSat) about the size of a briefcase that will use lasers to search for water ice inside craters at the Moon’s unexplored South Pole.

NASA says that the Lunar Flashlight, traveling aboard a SpaceX Falcon 9 rocket, will take about three months to reach its “science orbit.” The launch itself has been delayed: SpaceX has pushed back the launch several times. Currently, it is expected to launch later this month. 

The work on earth leading up to the launch has already taken quite some time.

Georgia Tech and GTRI have been instrumental in the development of the Lunar Flashlight mission. Researchers in Georgia Tech’s School of Aerospace Engineering worked with NASA’s Marshall Space Flight Center to develop the SmallSat’s novel propulsion system. Georgia Tech Research Institute (GTRI) collaborated to assemble and test the Lunar Flashlight.

Seasoned researchers were assisted by students in their efforts.

One such student is Mary Kate Broadway, a student assistant in GTRI’s Electro-Optical Systems Laboratory (EOSL), whose academic and professional experiences in modeling and fabrication were called upon to create a near 1:1 model of the Lunar Flashlight SmallSat.

Broadway, who is pursuing a bachelor’s degree in mechatronics, robotics, and automation engineering at Kennesaw State University, used GTRI’s SEEDLab makerspace to fashion the model based on designs produced by NASA.

“I got the SolidWorks (a popular solid modeling computer-aided design and computer-aided engineering application) file, and then I started by taking all the SolidWorks parts, making the 3D printables, and then exporting them out as ‘.stl’ files. Here (at the SEEDLab), I queued everything up and printed it,” Broadway explains. She did “all of the painting and the printing” by herself. "However, of course, the SEEDLab helpers (student assistants) all helped me whenever I had trouble.”

Broadway, who already has a BFA in animation and digital arts from Florida State University, has the savvy to make use of the SEEDLab’s wide variety of equipment.

For the Lunar Flashlight project, Broadway employed:

• An Ultimaker S5 FDM, a fused-filament fabrication 3D printer.
• A FormLabs Cameo resin printer.
• A Glowforge 3D laser printer and cutter.
• Various traditional hand tools.

Broadway employed traditional materials such as PET and PLA plastics for some of the more intricate parts of the model. The main body of the model is aluminum, which Broadway collaborated with the Aero Maker Space on the Georgia Tech campus to get pressed and fashioned to specifications with a Waterjet cutting machine. To simulate working solar panels, Broadway designed printed vinyl labels.

Broadway’s supervisor, EOSL Research Engineer Eric Brown, was initially contacted by Principal Research Engineer Jud Ready, Ph.D., who has worked extensively with NASA. Ready has been the liaison to NASA, reporting on Broadway’s progress.

As of Nov. 4, just days before the Lunar Flashlight launch, Broadway was still engrossed in making final adjustments to the model, particularly the tight tolerances of its solar arrays. Broadway began working on the Lunar Flashlight project in April. Working part-time at the SEEDLab, she has spent dozens of hours—amounting to about a month of work--perfecting the device.

Writer: Christopher Weems

Photos: Sean McNeil

GTRI Communications
Georgia Tech Research Institute
Atlanta, Georgia USA

The Georgia Tech Research Institute (GTRI) is the nonprofit, applied research division of the Georgia Institute of Technology (Georgia Tech). Founded in 1934 as the Engineering Experiment Station, GTRI has grown to more than 2,800 employees, supporting eight laboratories in over 20 locations around the country and performing more than $700 million of problem-solving research annually for government and industry. GTRI's renowned researchers combine science, engineering, economics, policy, and technical expertise to solve complex problems for the U.S. federal government, state, and industry.

During the 30-minute panel session, Garrow led the discussion on examining the new ways data and technology are helping create a more connected, efficient, and sustainable journey for modern airline passengers. The panelists were able to highlight how their companies are tracking information across the entire passenger journey, highlighting ways that they are adopting sophisticated data collection and analysis to make real-time operational decisions and improve the experience for customers across the globe.

United Airlines spotlighted its ConnectionSaver tool, which sends travelers messages with directions to the gate for their connecting flight, information about expected travel time between the two gates, and will even hold the flight for a few minutes.

Garrow also asked how artificial intelligence (AI) and machine learning are being used to improve technologies and make flying a smoother and more enjoyable process for passengers. Among the many initiatives mentioned, Enel-Réhel from Collins Aerospace spoke on that company’s ongoing efforts to develop and improve the technology used for predictive maintenance monitoring for aircraft to prevent unexpected maintenance issues. 

To close out the discussion, Garrow asked the panelists what’s next and how they see technology playing a role. Each panelist responded by emphasizing the importance of data collection, AI, and machine learning. 

Garrow expressed her appreciation for being invited to the panel saying, “It’s important as a woman [in] engineering to be featured at conferences like these.” She noted that there is an underrepresentation of women in aviation and emphasized the ongoing efforts to change that. 

Garrow is a professor in the School of Civil and Environmental Engineering and is the first woman and the first academic to serve as president in the Airline Group of the International Federation of Operational Research Societies’ 60-year history. In her role as co-director for the Center for Urban and Regional Air Mobility, she has conducted research in advanced air mobility that has focused on understanding demand for these new modes of transportation.

A key goal of the research will be to correlate the color changes that occur under low-Earth orbital (LEO) exposure with variations in the materials' properties – such as structural strength, chemical composition, and electrical conductivity – to determine how these spectral changes might allow scientists and engineers to visually assess deterioration. The LEO space environment exposes materials to the damaging effects of atomic oxygen, ultraviolet radiation, and high-energy electrons.

“We want to know not only how space affects materials, but also why that happens,” said Elena Plis, a senior research engineer at the Georgia Tech Research Institute (GTRI) who is leading the multi-organization research team. “For instance, we know that a commonly used material from DuPont, Kapton® polyimide film, is subject to changes in its conductivity in space, but we want to know why, how we might prevent that, or how we can use it to our benefit.”

Regularly photographing the materials in both visible and infrared spectral ranges will provide a dynamic record of what happens with optical properties in space, improving upon the knowledge that has often been limited to measurements before and after space exposure. The research team will extensively analyze the materials returned to Earth to understand better how space degradation may affect other material properties and use this information for long-term space mission planning.

“I’m interested in the dynamics of damage caused to materials in space,” explained Plis. “Up until now, we have generally only had two data points for assessing the effects of space: the pristine materials that we launch, and the cumulative effects we can see when materials are returned. The uniqueness of this experiment is in letting us watch the damage occur over time.”

Beyond GTRI, the research team includes researchers from the Air Force Research Laboratory (AFRL), NASA, the University of Texas at El Paso, and DuPont, a multi-industrial company headquartered in Wilmington, Del. Utilizing the Materials International Space Station Experiment (MISSE) Flight Facility, the research is also supported by Aegis Aerospace Inc., the company which owns and operates the MISSE platform installed on the ISS.

Analyzing the spectral data obtained by the experiment could also allow observers to determine whether a piece of space junk is from a lightweight insulating blanket or a heavier circuit board that could damage orbiting spacecraft. Beyond providing a new way to assess the structural health of materials remotely and assessing the risks from space debris, the experiment will also help engineers evaluate novel materials that could provide designers of future spacecraft with new options.

“DuPont Kapton® HN polyimide film, for instance, is a material that has been used ever since the Apollo missions, which makes it the gold standard,” Plis said. “But there are many more materials that may offer improved properties, so we are going to see how some examples of those are affected by space.”

Many of the materials being studied are used to protect spacecraft systems and crews from the effects of rapid thermal changes that take place in orbit, and from damaging electrical charging effects. The MISSE-16 materials selection includes different types of polyimides, liquid crystal polymers (LCP), polyhedral oligomeric silsesquioxane (POSS), carbon and glass fiber reinforced polymers, and polyethylene terephthalate (PET) polyester films.

The samples were installed on the exterior of the ISS using a robotic arm and will be retrieved in the same way in about six months. The samples will be placed on three different faces of the ISS to receive preferential exposures to atomic oxygen, ultraviolet radiation, and high-energy electrons. The samples were delivered to the ISS by a SpaceX Dragon cargo spacecraft that launched on July 16.

To facilitate the long-term observation on orbit, the MISSE testbed has been upgraded with a camera and illumination system to cover a broader spectral range, including infrared, which is important to observing certain aspects of degradation. The upgraded hardware will remain part of the MISSE instrumentation after the GTRI-led experiment is over.

The samples, which are one-inch squares, are expected to be returned to Earth next spring. The materials flown in space will be examined in detail to understand the degradation and compared to identical samples subjected to simulated space conditions in the laboratory. In all, the samples will be subjected to 10 different characterization techniques, including atomic force microscopy, optical characterization of reflection and absorptance, and measurements of electrical charge transfer.

“We will be trying to connect the optical properties with surface changes and chemical changes,” said Plis. “With our ground experiments, we hope to understand these changes and the physics that lies behind them.”

For Plis, who has been studying the effects of space exposure on materials since 2015, seeing the research launch into space was the result of a years-long application and development process.

“For me, launching the materials was very emotional,” she said. “It’s like a dream come true to be sending my research into space and getting data from space. This is my first project to go into space, and I hope there will be more.”

Writer: John Toon (John.Toon@gtri.gatech.edu)

About GTRI: The Georgia Tech Research Institute (GTRI) is the nonprofit, applied research division of the Georgia Institute of Technology (Georgia Tech). Founded in 1934 as the Engineering Experiment Station, GTRI has grown to more than 2,800 employees, supporting eight laboratories in over 20 locations around the country and performing more than $700 million of problem-solving research annually for government and industry. GTRI's renowned researchers combine science, engineering, economics, policy, and technical expertise to solve complex problems for the U.S. federal government, the state, and industry. For more information, please visit www.gtri.gatech.edu.

What if there was a way for the school supplies and food to be delivered right to your dorm – not by car or foot, but by drone?

One class that is part of the Vertically Integrated Projects (VIP) Program at the Georgia Tech Research Institute (GTRI) and Georgia Tech could soon turn that idea into a reality.

The class, called Experimental Flights, is developing a drone delivery network that would allow students on Georgia Tech's campus in Atlanta to place orders for items such as school supplies and food through a mobile app, and have a drone deliver those items to a secure locker station close to their dorm. The app would have a similar look and feel to the app used for popular ridesharing services and students could use it to view wait times for the next available drone, track their package, and receive a unique code to access their purchase.

Michael Mayo, a GTRI senior research engineer who is the lead instructor for the class, said his initial goal is to roll out the drone delivery network to students at Georgia Tech and then to consider other locations later on.

"We’ve been working on this kind of network for a couple of years now and have leveraged knowledge from a lot of different disciplines at Tech – including aerospace engineering, mechanical engineering, and computer science," Mayo said. "Success for this project would be for us to develop a fully-functional drone delivery network on Georgia Tech's campus that would serve as a model for future drone delivery networks across the country and world."

VIP is an education program supported by Tech and GTRI that allows undergraduate and graduate students to earn academic credit for working with faculty on projects they don't typically encounter in a classroom setting.

Student teams work closely with faculty advisors and graduate student mentors. Classes are held once a week, though team members usually hold additional meetings outside of class. Prospective students who are interested in joining the program can apply to a team that interests them on Tech's VIP website.

Diversity of Thought

The Experimental Flights class attracts a diverse group of class years and majors.

For the spring 2022 semester, the course included 33 undergraduate students ranging from first years to fourth years with the following majors: aerospace engineering, mechanical engineering, electrical engineering, and computer science. Twenty-one of the 33 students took the class in a previous semester.

One of those students is Catherine Heaton, a fourth-year aerospace engineering major who has participated in the Experimental Flights class since the fall 2020 semester. Heaton said working with a diverse group of students has enabled her to apply the concepts she has learned from her major to solve real-world issues, while also gaining experience developing hardware systems that supports emerging technologies.

"I'm on our class' hardware team, so I help assemble all of the parts of the drone and also work a little bit with 3D software modeling," Heaton said. "There's a lot of new technologies coming out – whether it's drones, or other plane-related things – and they all have so much potential."

Another student, Tim Boyer, a third-year electrical engineering major who has also been a member of the class since fall 2020, said he most enjoys VIP's interdisciplinary focus and getting the chance to tinker with drones.

"I really enjoy working with mechanical engineering and computer science majors to make a project come together," Boyer said. "It's also great because I have always been interested in drones, so this class is a great outlet to play around with that kind of hardware."

VIP Programs are now active in over 40 universities, with more than 4,500 students participating per term around the globe. The entire Georgia Tech VIP program currently serves 84 VIP teams involving more than 200 faculty and over 1,500 students. GTRI has 13 VIP teams that involve roughly 40 faculty members.

Preparing for Launch

Mayo's class has assembled a few drone prototypes with the help of drone assembly kits and 3D printing.

The cost to create one drone is under $1,000, and each prototype can currently carry packages that weigh up to 2 pounds, according to Mayo.

"The cost of drones, batteries and other associated components continue to decrease, which makes the economics of this type of delivery system more and more favorable," Mayo said.

Drone delivery offers several benefits to traditional car-based services, including the potential for reduced greenhouse gas emissions as smaller and lighter packages are transported via drones instead of delivery trucks. This alternative delivery method could also reduce roadway congestion and lower the risk of car accidents. Drone delivery could also enable greater route flexibility, resulting in consumers receiving their packages sooner.

Beyond package delivery, drones are useful in disaster relief settings when organizations need to send goods to places with restricted access, and also in military settings to help ground troops collect key intelligence and not risking helicopter crews to deliver supplies.

The Experimental Flights class has successfully completed initial flight testing for their drones in a controlled environment that has been approved by the Georgia Tech Police Department and demonstrated the drones' ability to transport small packages. The class has also constructed a prototype package locker that can securely store multiple packages and that the drone can directly drop packages into.

The class is currently designing the mobile app for end users and a flight control center to manage drone operation. The path the drone takes through campus for each delivery will be automatically generated using an algorithm designed by the class. The algorithm has been designed to optimize the drone's flight path to ensure maximum safety by avoiding flight over people while also reducing delivery times when possible. Drones will fly themselves autonomously to their destination during normal operation.

Mayo noted a fully-operational drone would transmit real-time telemetry and live video streams to the flight control center at all times, and in the event of an emergency, a human operator would assume manual control of the drone. Packages will be secured with both an electromagnet and with the landing gear of the drone itself during transport to reduce the risk of a package becoming dislodged during flight. Rotor cowlings will be added to the drones to minimize the chance of human contact with the rotors – or a fanlike component that drones rely on for propulsion and control – during normal operation and in the event that a drone flies off its approved path.

Before implementing a drone delivery network on campus, the class would need to gain approval from campus administrators and the Federal Aviation Administration (FAA).

"Special preparation will also need to be made to get FAA approval to fly the drones beyond visual line of sight, which is a requirement for most drone operations," Mayo said.

Once the drone delivery system becomes fully operational, the only initial cost to students would be the items that they order, Mayo said. An additional delivery cost, similar to those for food delivery services such as DoorDash and Uber Eats, could be included later on.

Looking ahead, the class aims to perform flight tests where the drone would pick up a sample package and deliver the item to a locker station in one trip.

Beyond the Classroom

Mayo's class is currently seeking corporate collaborations to apply their drone delivery concept to areas such as inventory management and more widespread package delivery. His class is currently collaborating with U.S. furniture company Steelcase to study the use of drones for indoor and outdoor inventory management.

Mayo said he considers a collaboration between students and companies to be a win-win for both groups. Companies are able to build relationships with students who have in-demand skills and who could be hired as entry-level employees. Students, meanwhile, are able to receive feedback from experienced engineers and network with a company that could serve as a potential employment opportunity.

"There are so many advantages to VIP that extend well beyond the classroom," Mayo said.

Writer: Anna Akins
Photos: Christopher Moore
GTRI Communications
Georgia Tech Research Institute
Atlanta, Georgia USA

The Georgia Tech Research Institute (GTRI) is the nonprofit, applied research division of the Georgia Institute of Technology (Georgia Tech). Founded in 1934 as the Engineering Experiment Station, GTRI has grown to more than 2,800 employees supporting eight laboratories in over 20 locations around the country and performing more than $700 million of problem-solving research annually for government and industry. GTRI's renowned researchers combine science, engineering, economics, policy, and technical expertise to solve complex problems for the U.S. federal government, state, and industry.

Infrasound waves can travel long distances – hundreds of miles – and are largely unaffected by obstacles in their way. Generally defined as frequencies below 20 Hertz, infrasound has until now been detected and measured using arrays up to an acre in size that use hollow pipes or elements similar to garden soaker hoses to separate the sounds of interest from noise created by the wind.

GTRI researchers have developed a novel infrasound analysis technique based on wavelet technology, a mathematical approach that represents a signal at different scales, using unique features at each scale. This technique, when applied to infrasound recordings, separates the wind noise from other signals of interest. That allows infrasound sensors to become small enough to be easily portable, permitting new types of measurements – including tracking small and large aircraft and studying effects on humans.

“We have been able to implement wavelet technology to get data more accurate than what has been possible using other methods of removing wind noise,” said Krishan Ahuja, Regents Professor and Researcher and head of GTRI’s Aerospace and Acoustics Technologies Division. “We have come up with a way to completely eliminate the hoses and reduce the size of the windscreen. This can all be done with signal processing.”

Hydrodynamic noise produced by wind has frequencies comparable to those of infrasound, so wind noise must be suppressed to obtain useful measurements. The most common way to achieve this has been to use long pipe arrays or large arrays of soaker hoses to gather the sound. The arrays allow pressure variations to be averaged over the length of the structure, thereby reducing the impact of the turbulent wind field. Other approaches to reduce wind noise use large tents covering the infrasound sensors, which also limits where they can be used.

The technique developed at GTRI uses smaller windscreens – or no windscreens at all – along with a wavelet denoising technique that breaks down the signal mathematically and then partitions out what is wind noise before reconstructing the remaining infrasound for analysis, explained Alessio Medda, a GTRI senior research engineer. The resulting reconstruction produces an infrasound signal in which the noise is greatly reduced.

Jupiter’s atmosphere has a system of zones and belts punctuated by small and large vortices, the largest being the Great Red Spot. How these features change with depth is unknown, with theories of their structure ranging from shallow meteorological features to surface expressions of deep-seated convection. Steffes and his colleagues present observations of atmospheric vortices using the Juno spacecraft’s Microwave Radiometer. They found vortex roots that extend deeper than the altitude at which water is expected to condense, and they identified density inversion layers. Their results constrain the three-dimensional structure of Jupiter’s vortices and their extension below the clouds.

Juno began its five-year-long journey to Jupiter when it launched from Kennedy Space Center on August 5, 2011. It has been circling Jupiter since entering its orbit on July 4, 2016. Slated to continue through September 2025 or through the end of the spacecraft’s life–whichever comes first, the mission will not only continue key observations of Jupiter, but also will expand its investigations to the larger Jovian system including Jupiter's rings and large moons, with targeted observations and close flybys planned of the moons Ganymede, Europa, and Io. 

To learn more, read the paper on the Science website.

On Nov. 11, Georgia Tech and the U.S. Space Force launched a strategic partnership to develop a high-caliber aerospace workforce and collaborate on advanced aerospace research. As part of a comprehensive agreement, the two parties signed a memorandum of understanding, making Georgia Tech the newest member of the U.S. Space Force’s University Partnership Program.

Lt. General Nina M. Armagno, U.S. Space Force director of staff, joined Georgia Tech Provost Steven W. McLaughlin and Executive Vice President for Research Chaouki T. Abdallah to sign the agreement. The signing ceremony, which fell on Veterans Day, took place on Georgia Tech’s campus.

“At the heart of the Space Force’s University Partnership Program is the need to advance our science and technology to build the next generation of space capabilities, while developing the workforce of the future,” Armagno said. “With its reputation as a leader in cutting-edge aerospace research, we are confident that Georgia Tech will be an outstanding partner.”

The U.S. Space Force — the sixth and newest branch of the U.S. Armed Forces — established the University Partnership Program to identify, develop, and retain a diverse, STEM-capable workforce to further its mission to protect U.S. and allied interests in space. Through the partnership, the Space Force will seek to recruit new members and also create educational and leadership development programs for existing Space Force employees. Georgia Tech was selected for its outstanding aerospace engineering research, its expertise in national defense and security, the diversity of its students, and its robust ROTC program.

“Georgia Tech is proud of its longstanding collaborations with NASA and the Department of Defense to help achieve strategic national objectives,” Abdallah said. “We look forward to charting bold new areas of research with the Space Force and leveraging our expertise in aerospace engineering and national security to address today’s most complex space-based military challenges”  

Georgia Tech joins 11 universities selected for the U.S. Space Force University Partnership Program in fiscal year 2021. They include Howard University, Massachusetts Institute of Technology, North Carolina Agricultural and Technical State University, Purdue University, University of Colorado Boulder, University of Colorado Colorado Springs, University of North Dakota, University of Southern California, University of Texas at Austin, and University of Texas at El Paso.

The institutions were selected based on four criteria: the quality of STEM degree offerings and space-related research laboratories and initiatives; ROTC program strength; diversity of student population; and degrees and programming designed to support military, veterans, and their families in pursuing higher education.

The signing ceremony was the culmination of a daylong campus visit for Lt. General Armagno and the Space Force delegation. In the morning, she met with Air Force ROTC students and gave a public talk at the Sam Nunn School of International Affairs about the Space Force’s integration into the U.S. military. In the afternoon, she held a discussion with aerospace engineering students, toured the Space Systems Design Lab, and received an overview of the Georgia Space Grant Consortium and Aerospace Engineering Outreach.

“Georgia Tech is honored to be selected as a Space Force University Partnership School, and we look forward to collaborating in educating leaders for the aerospace workforce of the future,” McLaughlin said. “I am confident that we will continue to drive technological advancements for the U.S. Space Force, just as we have done for NASA and the Department of Defense.”

As a next step, Georgia Tech and the Space Force will outline specific implementation milestones to meet the program’s objectives. This initial work will include establishing educational programs such as scholarships, internships, and mentorship opportunities, and identifying specific research areas of mutual benefit to the Space Force and Georgia Tech.

Those so-called terrestrial analog sites on Earth helped NASA choose Jezero for the mission. “Ancient lake beds are a major target for Mars exploration, as they provide evidence for sustained liquid water in Mars’ past — and lake muds commonly preserve biosignatures on Earth,” says Frances Rivera-Hernández, assistant professor in the School of Earth and Atmospheric Sciences. “Thus, if life ever persisted on early Mars, their past presence may be preserved in ancient lake beds.”

Rivera-Hernández, who joined Georgia Tech in January, will soon get a chance to study another analog site in the Antarctic, thanks to a four-year $700,000 NASA grant awarded to her research proposal, “Paleolake deposits in Miers Valley, Antarctica: An analog depositional record for Martian lakes through late Noachian to early Hesperian climatic transitions.”

Just like the drilling and sampling now going on at Jezero Crater on Mars, Rivera-Hernández’s work may help NASA choose future Mars destinations for both robotic rover and crewed missions. That’s because Rivera-Hernández is also a collaborating scientist on NASA’s Curiosity Rover mission. “Lessons learned through the Antarctic project will help inform my work on the mission, as we have been characterizing lake bed deposits with the Rover,” she says. Since landing on Mars in 2012, Curiosity has traveled nearly 26 km (16.14 miles) around the rim of Gale Crater, another probable dry lake.

“I was ecstatic to hear that my grant was funded, and excited to be heading to Antarctica for field work,” says Rivera-Hernández, who will serve as the study’s principal investigator. Her co-investigator is Tyler Mackey, an assistant professor at the University of New Mexico. The grant will also provide funding for two graduate students, one from each institution. Field work is planned to start in January 2024.

“Before the field season, we will be performing remote sensing observations of our field site and performing lab-based analyses on modern lake samples to plan for the field work studying ancient lake beds,” Rivera-Hernández says. 

Her lab team will study the deposits of a large Antarctic lake that persisted through climate changes 10,000 to 20,000 years ago to better recognize those similar changes in ancient lake beds on Mars, like those being explored by Curiosity and Perseverance. 

“Currently, liquid water is not stable on the surface of Mars, but we have abundant geologic evidence for the presence of lakes on early Mars, suggesting that Mars’ climate was different in the past and that it changed through time,” Rivera-Hernández says. “But we still do not have a good understanding on whether this climatic transition was abrupt or gradual, or if Mars was significantly warmer when the lakes were present.”

That’s an unknown because lakes can form in a variety of climates, she adds. Examples are found in polar regions on Earth, where liquid water exists in lakes with permanent ice covers. “However, when ice is present in a lake, there are processes that are unique, and sometimes these produce deposits that may be recorded in lake beds. Thus, past climate may be inferred from lake beds if these unique deposits are recognized and distinguished from other deposit types.”

Rivera-Hernadez’s project will also help scientists recognize these unique deposits in ancient lake beds on Mars — by studying the deposits of that ancient Antarctic lake which experienced periods with and without an ice cover, due to those climatic changes on Earth.

For years, NASA has been studying ice on the Moon. Now, they want to determine where it is exactly and just how much, and a spacecraft at Georgia Tech could provide definitive answers. Georgia Tech engineers and researchers will work with NASA's Jet Propulsion Laboratory (JPL) in Southern California to assemble, integrate and test a small satellite mission known as Lunar Flashlight.

A research team at the Georgia Institute of Technology has developed a modular solution for handling larger packages without the need for a complex fleet of drones of varying sizes. By allowing teams of small drones to collaboratively lift objects using an adaptive control algorithm, the strategy could allow a wide range of packages to be delivered using a combination of several standard-sized vehicles.

Beyond simplifying the drone fleet, the work could provide more robust drone operations and reduce the noise and safety concerns involved in operating large autonomous UAVs in populated areas. In addition to commercial package delivery, the system might also be used by the military to resupply small groups of soldiers in the field.

“A delivery truck could carry a dozen drones in the back, and depending on how heavy a particular package is, it might use as many as six drones to carry the package,” said Jonathan Rogers, the Lockheed Martin Associate Professor of Avionics Integration in Georgia Tech’s Daniel Guggenheim School of Aerospace Engineering. “That would allow flexibility in the weight of the packages that could be delivered and eliminate the need to build and maintain several different sizes of delivery drones.”

The research was supported, in part, by a National Science Foundation graduate student fellowship and by the Hives independent research and development program of the Georgia Tech Research Institute. A paper on the research has been submitted to the Journal of Aircraft.

A centralized computer system developed by graduate student Kevin Webb would monitor each of the drones lifting a package, sharing information about their location and the thrust being provided by their motors. The control system would coordinate the issuance of commands for navigation and delivery of the package.

“The idea is to make multi-UAV cooperative flight easy from the user perspective,” Rogers said. “We take care of the difficult issues using the onboard intelligence, rather than expecting a human to precisely measure the package weight, center of gravity, and drone relative positions. We want to make this easy enough so that a package delivery driver could operate the system consistently.”

The challenges of controlling a group of robots connected together to lift a package is more complex in many ways than controlling a swarm of robots that fly independently.

“Most swarm work involves vehicles that are not connected, but flying in formations,” Rogers said. “In that case, the individual dynamics of a specific vehicle are not constrained by what the other vehicles are doing. For us, the challenge is that the vehicles are being pulled in different directions by what the other vehicles connected to the package are doing.” 

The team of drones would autonomously connect to a docking structure attached to a package, using an infrared guidance system that eliminates the need for humans to attach the vehicles. That could come in handy for drones sent to retrieve packages that a customer is returning. By knowing how much thrust they are producing and the altitude they are maintaining, the drone teams could even estimate the weight of the package they’re picking up.

Webb and Rogers have built a demonstration in which four small quadrotor drones work together to lift a box that’s 2 feet by 2 feet by 2 feet and weighs 12 pounds. The control algorithm isn’t limited to four vehicles and could manage “as many vehicles as you could put around the package,” Rogers said.

For the military, the modular cargo system could allow squads of soldiers at remote locations to be resupplied without the cost or risk of operating a large autonomous helicopter. A military UAV package retrieval team could be made up of individual vehicles carried by each soldier.

“That would distribute a big lifting capability in smaller packages, which equates to small drones that could be used to team up,” Rogers said. “Putting small drones together would allow them to do bigger things than they could do individually.”

Bringing multiple vehicles together creates a more difficult control challenge, but Rogers argues the benefits are worth the complexity. “The idea of having multiple machines working together provides better scalability than building a larger device every time you have a larger task,” he said. “We think this is the right way to fill that gap.”

Using multiple drones to carry a heavy package could also allow more redundancy in the delivery system. Should one of the drones fail, the others should be able to pick up the load – an issue managed by the central control system. That part of the control strategy hasn’t yet been tested, but it is part of Rogers’ plan for future development of the system.

More research is also needed on the docking system that connects the drones to packages. The structures will have to be made strong and rigid enough to connect to and lift the packages, while being inexpensive enough to be disposable.

“I think the major technologies are already here, and given an adequate investment, a system could be fielded within five years to deliver packages with multiple drones,” Rogers said. “It’s not a technical challenge as much as it is a regulatory issue and a question of societal acceptance.”

Research News
Georgia Institute of Technology
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Media Relations Contacts: John Toon (404-894-6986) (jtoon@gatech.edu) or Anne Wainscott-Sargent (404-435-5784) (asargent7@gatech.edu).

Writer: John Toon

Conducted in July 2020, the study included monitoring both the number of particles and their total mass across a broad range of indoor locations, including 19 commercial flights in which measurements took place throughout departure and arrival terminals, the boarding process, taxiing, climbing, cruising, descent, and deplaning. The monitoring could not identify the types of the particles and therefore does not provide a direct measure of coronavirus exposure risk.

“We wanted to highlight how important it is to have a high ventilation rate and clean air supply to lower the concentration of particles in indoor spaces,” said Nga Lee (Sally) Ng, associate professor and Tanner Faculty Fellow in the School of Chemical and Biomolecular Engineering and the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. “The in-flight cabin had the lowest particle mass and particle number concentration.”

The study, believed to be the first to measure both size-resolved particle mass and number in commercial flights from terminal to terminal and a broad range of indoor spaces, has been accepted for publication in the journal Indoor Air and posted online at the journal’s website. Supported by Delta Air Lines, the research may be the first to comprehensively measure particle concentrations likely to be encountered by passengers from terminal to terminal.

As scientists learn more about transmission of the coronavirus, the focus has turned to aerosol particles as an important source of viral spread indoors. Infected people can spread the virus as they breathe, talk, or cough, creating particles ranging in size from less than a micron — one millionth of a meter — to 1,000 microns. The larger particles quickly fall out of the air, but the smaller ones remain suspended.

“Especially in poorly ventilated spaces, these particles can be suspended in the air for a long period of time, and can travel to every corner of a room,” Ng said. “If they are viral particles, they can infect people who may be at a considerable distance from a person emitting the particles.”

To better understand the circulation of airborne particles, Delta approached Ng to conduct a study of multiple indoor environments, with a strong focus on air travel conditions. Using handheld instruments able to measure the total number of particles and their mass, Georgia Tech researchers examined air quality in a series of Atlanta area restaurants, stores, offices, homes, and vehicles — including buses, trains, and private automobiles. 

They trained Delta staff to conduct the same type of measurements in terminals, boarding areas, and a variety of aircraft through all phases of flight. The Delta staff recorded their locations as they moved through the terminals, and the instruments produced measurements consistent with the restaurants and stores they passed on their way to and from boarding and departure gates.

“The measurements started as soon as they stepped into the departure terminal,” Ng said. “We were thinking about the whole trip, what a person would encounter from terminal to terminal.”

In flight, aircraft air is exchanged between 10 and 30 times per hour. Some aircraft bring in exclusively outside air, which at cruising altitude is largely free of pollutant particles found in air near the ground. Other aircraft mix outdoor air with recirculated air that goes through HEPA filters, which remove more than 99% of particles. 

In all, the researchers evaluated measurements from 19 commercial flights with passenger loads of approximately 50%. The flights included a mix of short- and medium-length flights, and aircraft ranging from the CRJ-200 and A220 to the 757, A321, and 737.

Among all the spaces measured, restaurants had the highest particle levels because of cooking being done there. Stores were next, followed by vehicles, homes, and offices. The average sub-micron particle number concentration measured in restaurants, for instance, was 29,400 particles per cubic centimeter, and in offices it was 2,473 per cubic centimeter.  

“We have quite a comprehensive data set to look at the size distribution of particles across these different spaces,” Ng said. “We can now compare indoor air quality in a variety of different spaces.”

Because of the portable instruments used, the researchers were unable to determine the source of the particles, which could have included both biological and non-biological sources. “Further studies can include direct measurements of viral loads and tracing particle movements in indoor spaces,” she added.

Jonathan Litzenberger, Delta’s managing director of Global Cleanliness Strategy, said the research helps advance the company’s goals of protecting its customers and employees.

“Keeping the air clean and safe during flight is one of the most foundational layers of protection Delta aims to provide to our customers and employees,” he said. “We are always working to better understand the travel environment and confirm that the measures we are implementing are working.”

Overall, the study highlights the importance of improving indoor air quality as a means of reducing coronavirus transmission.

“Regardless of whether you are in an office or an aircraft, having a higher ventilation rate and good particle filtration are the keys to reducing the total particle concentration,” said Ng. “That should also reduce the concentration of any viral particles that may be present.”

In addition to Ng, the researchers included Jean C. Rivera-Rios, Taekyu Joo, Masayuki Takeuchi, and Thomas M. Orlando from Georgia Tech; and Tracy Bevington, John W. Mathis, Clifton D. Pert, Brandon A. Tyson, Tyler M. Anderson-Lennert, and Joshua A. Smith from Delta Air Lines.

CITATION: Jean C. Rivera-Rios, et al, “In-flight particulate matter concentrations in commercial flights are likely lower than other indoor environments.” (Indoor Air, 2021) https://doi.org/10.1111/ina.12812

Research News
Georgia Institute of Technology
177 North Avenue
Atlanta, Georgia  30332-0181  USA

Media Relations Contacts: John Toon (404-894-6986) (jtoon@gatech.edu) or Anne Wainscott-Sargent (404-435-5784) (asargent7@gatech.edu).

Writer: John Toon

Built with wheeled appendages that can be lifted and wheels able to wiggle, a new robot known as the “Mini Rover” has developed and tested complex locomotion techniques robust enough to help it climb hills covered with such granular material – and avoid the risk of getting ignominiously stuck on some remote planet or moon. 

Using a complex move the researchers dubbed “rear rotator pedaling,” the robot can climb a slope by using its unique design to combine paddling, walking, and wheel spinning motions. The rover’s behaviors were modeled using a branch of physics known as terradynamics.

“When loose materials flow, that can create problems for robots moving across it,” said Dan Goldman, the Dunn Family Professor in the School of Physics at the Georgia Institute of Technology. “This rover has enough degrees of freedom that it can get out of jams pretty effectively. By avalanching materials from the front wheels, it creates a localized fluid hill for the back wheels that is not as steep as the real slope. The rover is always self-generating and self-organizing a good hill for itself.”

The research was reported on May 13 as the cover article in the journal Science Robotics. The work was supported by the NASA National Robotics Initiative and the Army Research Office.

A robot built by NASA’s Johnson Space Center pioneered the ability to spin its wheels, sweep the surface with those wheels and lift each of its wheeled appendages where necessary, creating a broad range of potential motions. Using in-house 3D printers, the Georgia Tech researchers collaborated with the Johnson Space Center to re-create those capabilities in a scaled-down vehicle with four wheeled appendages driven by 12 different motors.

“The rover was developed with a modular mechatronic architecture, commercially available components, and a minimal number of parts,” said Siddharth Shrivastava, an undergraduate student in Georgia Tech’s George W. Woodruff School of Mechanical Engineering. “This enabled our team to use our robot as a robust laboratory tool and focus our efforts on exploring creative and interesting experiments without worrying about damaging the rover, service downtime, or hitting performance limitations.” 

The rover’s broad range of movements gave the research team an opportunity to test many variations that were studied using granular drag force measurements and modified Resistive Force Theory. Shrivastava and School of Physics Ph.D. candidate Andras Karsai began with the gaits explored by the NASA RP15 robot, and were able to experiment with locomotion schemes that could not have been tested on a full-size rover.

The researchers also tested their experimental gaits on slopes designed to simulate planetary and lunar hills using a fluidized bed system known as SCATTER (Systematic Creation of Arbitrary Terrain and Testing of Exploratory Robots) that could be tilted to evaluate the role of controlling the granular substrate. Karsai and Shrivastava collaborated with Yasemin Ozkan-Aydin, a postdoctoral research fellow in Goldman’s lab, to study the rover motion in the SCATTER test facility. 

“By creating a small robot with capabilities similar to the RP15 rover, we could test the principles of locomoting with various gaits in a controlled laboratory environment,” Karsai said. “In our tests, we primarily varied the gait, the locomotion medium, and the slope the robot had to climb. We quickly iterated over many gait strategies and terrain conditions to examine the phenomena that emerged.”

In the paper, the authors describe a gait that allowed the rover to climb a steep slope with the front wheels stirring up the granular material – poppy seeds for the lab testing – and pushing them back toward the rear wheels. The rear wheels wiggled from side-to-side, lifting and spinning to create a motion that resembles paddling in water. The material pushed to the back wheels effectively changed the slope the rear wheels had to climb, allowing the rover to make steady progress up a hill that might have stopped a simple wheeled robot.

The experiments provided a variation on earlier robophysics work in Goldman’s group that involved moving with legs or flippers, which had emphasized disturbing the granular surfaces as little as possible to avoid getting the robot stuck.

“In our previous studies of pure legged robots, modeled on animals, we had kind of figured out that the secret was to not make a mess,” said Goldman. “If you end up making too much of a mess with most robots, you end up just paddling and digging into the granular material. If you want fast locomotion, we found that you should try to keep the material as solid as possible by tweaking the parameters of motion.”

But simple motions had proved problematic for Mars rovers, which got stuck in granular materials. Goldman says the gait discovered by Shrivastava, Karsai and Ozkan-Aydin might be able to help future rovers avoid that fate.

“This combination of lifting and wheeling and paddling, if used properly, provides the ability to maintain some forward progress even if it is slow,” Goldman said. “Through our laboratory experiments, we have shown principles that could lead to improved robustness in planetary exploration – and even in challenging surfaces on our own planet.”

The researchers hope next to scale up the unusual gaits to larger robots, and to explore the idea of studying robots and their localized environments together. “We’d like to think about the locomotor and its environment as a single entity,” Goldman said. “There are certainly some interesting granular and soft matter physics issues to explore.”

Though the Mini Rover was designed to study lunar and planetary exploration, the lessons learned could also be applicable to terrestrial locomotion – an area of interest to the Army Research Laboratory, one of the project’s sponsors.

"This basic research is revealing exciting new approaches for locomotion in complex terrain," said Dr. Samuel Stanton, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "This could lead to platforms capable of intelligently transitioning between wheeled and legged modes of movement to maintain high operational tempo."

Beyond those already mentioned, the researchers worked with Robert Ambrose and William Bluethmann at NASA, and traveled to NASA JSC to study the full-size NASA RP15 rover.

This work was supported by the Army Research Office (W911NF-18-1-0120) and the NASA National Robotics Initiative (NNX15AR21G). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsoring agencies.

CITATION: Siddharth Shrivastava, Andras Karsai, Yasemin Ozkan-Aydin, Ross Pettinger, William Bluethmann, Robert O. Ambrose, Daniel I. Goldman, “Material remodeling on granular terrain yields robustness benefits for a robophysical rover.” (Science Robotics, May 2020)

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Georgia Institute of Technology
177 North Avenue
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Media Relations Contact: John Toon (404-894-6986) (jtoon@gatech.edu)

Writer: John Toon

DDM Systems, a company formed by a Georgia Tech team led by Suman Das, a professor in the George W. Woodruff School of Mechanical Engineering, was one of five finalists and the only one from the United States nominated for a prestigious industrial award presented annually at the international industrial fair Hannover Messe.

Das’ team developed a machine that uses advanced 3D printing technology specifically designed to make ceramic cores and molds used by foundries to cast highly demanding and complex parts such as aircraft turbine engine components.

The machine, called the LAMP™ System CPT6060, makes the ceramic pieces directly from a computer-aided design file, drastically reducing the production time when compared with the traditional method of making castings.

The ceramic cores and molds are in great demand by manufacturers making precision components for a diverse group of applications, including aerospace, energy, biomedical and automotive industries. Traditionally, the process of making the molds involves numerous steps including injection molding a ceramic core, creating a wax model around the core, and using a ceramic slurry to slowly build a shell mold around the wax.

The LAMP machine circumvents that process by fabricating the mold directly from a digital design. In addition to the faster turnaround time, the new technique can reduce the cost of making the molds by as much as 65 percent for new component designs.

The development of LAMP technology began in 2007 with funding from the Defense Advanced Research Projects Agency (DARPA). In 2012, Das and John Halloran, a professor at the University of Michigan and Das’ co-principal investigator for the $6.3 million project, formed DDM Systems Inc. to help bring the technology to market.

The LAMP system works by converting a digital design into thousands of high-resolution images that the machine uses to build parts a single 100-micron layer at a time using a slurry mixture of photosensitive binder resin and ceramic particles.

The 3D printer is large enough to simultaneously build numerous parts during one session. Once the resin is removed from the molds, they are ready for use in casting.

Aside from its use in fabricating ceramic cores and molds for investment casting, the LAMP system is also capable of 3D printing a variety of other complex pieces from the ceramic slurry.

Das, who directs the Direct Digital Manufacturing Laboratory at Georgia Tech, called the environment at the institute crucial to supporting the development of the technology.

“The Georgia Tech Manufacturing Institute provided tremendous support,” Das said. “That allowed me to have the environment, the facilities, and the infrastructure to be able to do this kind of work – to be able to design and build these pieces of equipment and to really start to put all of these things together to a point where it wasn’t just a science project.”

The GTMI’s reputation for working closely with industrial firms to find innovations also leads to advancements such as LAMP being developed on campus.

“Every single day, someone from some industry is here on campus,” Das said. “Being able to interact with these kinds of people and getting to know what industry needs was extremely important. That doesn’t happen simply by people visiting. It happens when you’re embedded in an environment that encourages that, and is known for that.”

Das also relied on the Georgia Tech Integrated Programs for Startups (GT:IPS), which provides guidance for students and faculty aiming to launch start-up firms to translate discoveries made in labs on campus, as well as VentureLab, which helps create startup companies based on Georgia Tech research.

From its beginnings, the project exemplified Georgia Tech’s mission of using research and innovation to educate a host of students during their academic pursuits, Das said.

“The project played a critical role in the training of Master’s and Ph.D. students who participated in the incubation of a groundbreaking technology, a rare opportunity,” Das said. “And ultimately they all graduated and they’re having successful careers elsewhere. So it was a success story from that point as well.”

In addition to LAMP technology, DDM Systems is also commercializing a technology called Scanning Laser Epitaxy, which can be used to repair existing aircraft engine parts and build entirely new parts in the most demanding high-temperature alloys through additive manufacturing techniques. The company has licensed both technologies from Georgia Tech.

While Hannover Messe’s 2016 HERMES Award was given to another finalist, Das said the opportunity to showcase DDM’s technologies before an international audience represented an important milestone in the evolution of the company.

“Becoming the first US company to have received a top 5 nomination in the history of the award led to tremendous recognition, including a meeting with President Barack Obama and German Chancellor Angela Merkel, as well as other U.S. and German trade officials,” Das said.

Hudgens holds a Ph.D. in ceramic engineering from Iowa State University. He has led research and development programs in national security, cybersecurity, quantum information science, and photonic microsystems. He also led programs in data analytics, synthetic aperture radar, and airborne intelligence, surveillance and reconnaissance (ISR) systems before becoming director of the $265 million-per-year TIC, which has a staff of 550 professionals working in six states and 136 different laboratories. 

A senior technology executive with 23 years of experience in national security research, Hudgens has also held positions at optical networking firm Mahi Networks, defense contractor Raytheon Electronic Systems, and semiconductor company Texas Instruments. In 2013, he won the Department of Energy Secretary’s Honor Award for Achievement for leading the Copperhead counter-IED program.

“Jim Hudgens has extensive experience building and leading federally sponsored programs that are at the center of GTRI’s core research areas,” said Chaouki Abdallah, Georgia Tech’s Executive Vice President for Research. “His experience developing and managing programs at Sandia National Laboratories and major private-sector defense contractors will support GTRI’s continued growth in service to our nation’s defense agencies and other important state and federal sponsors.”

GTRI has more than 2,300 employees conducting nearly $500 million worth of research across a broad range of technology areas that focus on solving critical challenges for government and industry sponsors. GTRI is one of the world’s leading applied research and development organizations, and is an integral part of Georgia Tech’s research program.

“Georgia Tech, through GTRI, is entrusted with a vital role in our national security,” Hudgens said. “I know firsthand that GTRI and other Georgia Tech researchers are known for the exceptional quality of their work in delivering innovative solutions to the most complex national security challenges.

“It is a great privilege for me to join the combined University System of Georgia and Georgia Tech family to develop a shared vision for how we will build on this reputation to advance one of the nation’s leading technological research universities,” he added. “I thank Georgia Tech President G.P. “Bud” Peterson, Provost Rafael Bras, and Executive Vice President Abdallah for the honor of becoming part of GTRI’s 85-year legacy of service to the state of Georgia and our nation.”

In congratulating Hudgens, Peterson emphasized GTRI’s important role in the nation, region, state – and Georgia Tech itself.

“For decades, the U.S. government and industry have looked to Georgia Tech – in particular GTRI – as they seek to find and develop effective, creative solutions in national security and other mission-critical areas,” Peterson said. “We are pleased to welcome Jim Hudgens to lead one of Georgia Tech’s most important missions in support of our nation, region, and state.”

Hudgens’ selection came after a five-month national search during which he was one of four finalists to make presentations to Georgia Tech faculty and staff.

Sandia National Laboratories is a multi-mission laboratory operated for the U.S. Department of Energy’s National Nuclear Security Administration. Sandia has major research and development responsibilities in nuclear deterrence, global security, defense, energy technologies, and economic competitiveness, with main facilities in Albuquerque, New Mexico, and Livermore, California. Sandia is the largest of the country’s 17 national laboratories.

GTRI conducts research through eight laboratories located on Georgia Tech’s midtown Atlanta campus, in a research facility near Dobbins Air Reserve Base in Smyrna, Georgia, and in Huntsville, Alabama. GTRI also has more than a dozen locations around the nation where it serves the needs of its research sponsors. GTRI’s research spans a variety of disciplines, including autonomous systems, cybersecurity, electromagnetics, electronic warfare, modeling and simulation, sensors, systems engineering, test and evaluation, and threat systems.

Media Relations Assistance: John Toon (404-894-6986) (jtoon@gatech.edu).

Writer: John Toon

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As the volume of data continues to expand, however, many agencies are considering the use of commercial cloud services to help store and make it available to users. While agencies may have different strategies, these new partnerships could result in user fees levied on downloads and analyses performed on the data while it remains in the cloud.

Writing in a policy forum article published February 8 in the journal Science, a Georgia Institute of Technology space policy researcher who studies such data use urges caution about the design of these commercial cloud partnerships and possible imposition of user fees.

“Under the current system, free and open government data is used by scientists to conduct research, by entrepreneurs to create new businesses, and by citizens and other organizations to promote government transparency,” said Mariel Borowitz, an assistant professor in Georgia Tech’s Sam Nunn School of International Affairs. “If users must pay fees to download or analyze the data, this will decrease the ability of these users to access and work with data. Past experience suggest that the impacts of this decrease in data use could be large – both for individual users and for society as a whole.”

Moving data to commercial cloud systems would likely provide broader access and more efficient analysis options, but she cautions those advantages could be offset by the cost, particularly for organizations with small budgets.

“Agencies risk losing some of the benefits of this transition by not budgeting for the costs associated with data downloads and analysis, up to a reasonable level,” Borowitz said. “Many who would be interested in using the data may not be able to pay the associated fees. Researchers, nonprofit organizations and others who do not directly profit from the use of this data are most likely to be affected.”

Borowitz recently spent two years at NASA and witnessed both the development of systems that will dramatically increase data collection and debates about future data storage. She recently authored a book, Open Space: The Global Effort for Open Access to Environmental Satellite Data, published by MIT Press. 

She would like to see the agencies that provide data continue to shoulder the costs, up to some “reasonable level,” to ensure that the data continues to be readily available to all users. As an alternative to commercial services, some agencies are considering development of their own, custom-built cloud solutions, and will have to weigh the cost of benefits of the different options. There will also be technical, organizational and policy issues to consider.

“Agencies are taking seriously issues of security and long-term preservation of data,” Borowitz added. “When working with commercial providers, some are concerned about the possibility of getting ‘locked in’ to one provider, due to the large costs of migrating data from one system to another. It is possible that costs and capabilities could change over time. On the other hand, commercial cloud providers have large workforces and extensive infrastructure that allow them to provide services and capabilities well beyond what any one agency would be able to maintain.”

Borowitz notes that most agencies have not made final decisions about their cloud-based programs, so there should be adequate time to work through these issues.

“Most agencies that make data publicly available, particularly science agencies, are already discussing and/or beginning to make the transition to cloud systems,” she said. “However, these programs – at agencies like NSF, NIH, NASA and NOAA – are still in their early phases, and there is still opportunity for feedback to be provided and adjustments to the programs to be made.”

The existence of fees for access to government data is not without precedent, but Borowitz argues that past experience suggests that user fees result in significantly less use. Before Landsat data – satellite imagery of Earth – was made freely available in 2008, no more than 25,000 images a year were purchased from the collection. “Within a few years of implementing the free and open data policy, the government was distributing 250,000 images a month,” she said.

That number provides a suggestion of what the often cash-strapped agencies are dealing with. According to the paper, the National Oceanic and Atmospheric Administration (NOAA) houses more than 100 petabytes (PB) of data and generates more than 30 PB per year from satellites, radars, computer models and other sources. NASA projects that its archive will grow to 250 PB by 2025. And the amount of genomic data at the National Institutes of Health is growing exponentially.

A petabyte is 1,024 terabytes, or a million gigabytes. A gigabyte is 1,024 megabtyes. For scale, an average photograph taken by a high-end cell phone camera can be in the neighborhood of 10 megabytes. Laptop computers may be able to store as much as a few terabytes of data.

Borowitz sees the transition to cloud computing as both an opportunity and a challenge for the future availability of government data. “The decisions being made right now about the structure of these programs have the potential to significantly impact researchers and society as a whole, so it is important to raise awareness and increase engagement on these issues.”

CITATION: Mariel Borowitz, “Government data, commercial cloud: Will public access suffer?” (Science, 2019) http://science.sciencemag.org/content/363/6427/588

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New research led by researchers from Georgia Institute of Technology, Dublin City University, Michigan State University, the University of California at San Diego, the San Diego Supercomputer Center and IBM provides a new and extremely promising avenue for solving this cosmic riddle. The team showed that when galaxies assemble extremely rapidly – and sometimes violently – that can lead to the formation of very massive black holes. In these rare galaxies, normal star formation is disrupted and black hole formation takes over. 

The new study finds that massive black holes form in dense starless regions that are growing rapidly, turning upside down the long-accepted belief that massive black hole formation was limited to regions bombarded by the powerful radiation of nearby galaxies. Conclusions of the simulation-based study, reported January 23 in the journal Nature and supported by funding from the National Science Foundation, the European Union and NASA, also finds that massive black holes are much more common in the universe than previously thought.

The key criteria for determining where massive black holes formed during the universe’s infancy relates to the rapid growth of pre-galactic gas clouds that are the forerunners of all present-day galaxies, meaning that most supermassive black holes have a common origin forming in this newly discovered scenario, said John Wise, an associate professor in the Center for Relativistic Astrophysics in Georgia Tech’s School of Physics and the paper’s corresponding author. Dark matter collapses into halos that are the gravitational glue for all galaxies. Early rapid growth of these halos prevented the formation of stars that would have competed with black holes for gaseous matter flowing into the area.

“In this study, we have uncovered a totally new mechanism that sparks the formation of massive black holes in particular dark matter halos,” Wise said. “Instead of just considering radiation, we need to look at how quickly the halos grow. We don’t need that much physics to understand it – just how the dark matter is distributed and how gravity will affect that. Forming a massive black hole requires being in a rare region with an intense convergence of matter.”

When the research team found these black hole formation sites in the simulation they were at first stumped, said John Regan, research fellow in the Centre for Astrophysics and Relativity in Dublin City University. The previously accepted paradigm was that massive black holes could only form when exposed to high levels of nearby radiation. 

“Previous theories suggested this should only happen when the sites were exposed to high levels of star-formation killing radiation,” he said. “As we delved deeper, we saw that these sites were undergoing a period of extremely rapid growth. That was the key. The violent and turbulent nature of the rapid assembly, the violent crashing together of the galaxy’s foundations during the galaxy’s birth prevented normal star formation and led to perfect conditions for black hole formation instead. This research shifts the previous paradigm and opens up a whole new area of research.”

The earlier theory relied on intense ultraviolet radiation from a nearby galaxy to inhibit the formation of stars in the black hole-forming halo, said Michael Norman, director of the San Diego Supercomputer Center at UC San Diego and one of the work’s authors. “While UV radiation is still a factor, our work has shown that it is not the dominant factor, at least in our simulations,” he explained.

The research was based on the Renaissance Simulation suite, a 70-terabyte data set created on the Blue Waters supercomputer between 2011 and 2014 to help scientists understand how the universe evolved during its early years. To learn more about specific regions where massive black holes were likely to develop, the researchers examined the simulation data and found ten specific dark matter halos that should have formed stars given their masses but only contained a dense gas cloud. Using the Stampede2 supercomputer, they then re-simulated two of those halos – each about 2,400 light-years across – at much higher resolution to understand details of what was happening in them 270 million years after the Big Bang.

“It was only in these overly-dense regions of the universe that we saw these black holes forming,” Wise said. “The dark matter creates most of the gravity, and then the gas falls into that gravitational potential, where it can form stars or a massive black hole.”

The Renaissance Simulations are the most comprehensive simulations of the earliest stages of the gravitational assembly of the pristine gas composed of hydrogen and helium and cold dark matter leading to the formation of the first stars and galaxies. They use a technique known as adaptive mesh refinement to zoom in on dense clumps forming stars or black holes. In addition, they cover a large enough region of the early universe to form thousands of objects—a requirement if one is interested in rare objects, as is the case here. “The high resolution, rich physics and large sample of collapsing halos were all needed to achieve this result,” said Norman.

The improved resolution of the simulation done for two candidate regions allowed the scientists to see turbulence and the inflow of gas and clumps of matter forming as the black hole precursors began to condense and spin. Their growth rate was dramatic.

“Astronomers observe supermassive black holes that have grown to a billion solar masses in 800 million years,” Wise said. “Doing that required an intense convergence of mass in that region. You would expect that in regions where galaxies were forming at very early times.”

Another aspect of the research is that the halos that give birth to black holes may be more common than previously believed.

“An exciting component of this work is the discovery that these types of halos, though rare, may be common enough,” said Brian O’Shea, a professor at Michigan State University.  “We predict that this scenario would happen enough to be the origin of the most massive black holes that are observed, both early in the universe and in galaxies at the present day.”   

Future work with these simulations will look at the lifecycle of these massive black hole formation galaxies, studying the formation, growth and evolution of the first massive black holes across time. “Our next goal is to probe the further evolution of these exotic objects. Where are these black holes today? Can we detect evidence of them in the local Universe or with gravitational waves?” Regan asked. 

For these new answers, the research team – and others – may return to the simulations.

“The Renaissance Simulations are sufficiently rich that other discoveries can be made using data already computed,” said Norman. “For this reason we have created a public archive at SDSC containing called the Renaissance Simulations Laboratory where others can pursue questions of their own.”

This research was supported by the National Science Foundation through grants PHY-1430152, AST-1514700, AST-161433 and OAC-1835213, by NASA grants NNX12AC98G, 147 NNX15AP39G, and NNX17AG23G, and by Hubble theory grants HST-AR-13261.01, HST-AR-14315.001, and HST-AR-14326. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 699941 (Marie Sklodowska-Curie Actions – “SmartStars). The simulation was performed on the Blue Waters supercomputer operated by the National Center for Supercomputing Applications (NCSA) with PRAC allocation support by the NSF (awards ACI-0832662, ACI-1238993 and ACI-1514580). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsor organizations.

CITATION: John H. Wise, et al., “Formation of massive black holes in rapidly growing pre-galactic gas clouds,” (Nature 2019). http://dx.doi.org/10.1038/s41586-019-0873-4

Renaissance Simulations Laboratory: https://rensimlab.github.io

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Gravitational waves, hard-to-see ripples in the fabric of space-time, had been predicted by Albert Einstein’s General Theory of Relativity in 1915. These gravitational waves carry information about their origins, potentially offering a new way to observe the cosmos. Three years ago, however, researchers didn’t know if this first observation was merely an anomaly or part of a widespread phenomenon that could teach us about the population of black holes in the universe.

A dozen Georgia Tech faculty members, postdoctoral researchers, and students participated with hundreds of other researchers in the National Science Foundation-sponsored LIGO (Laser Interferometer Gravitational-Wave Observatory) Scientific Collaboration that reported the first gravitational waves. After the announcement, the work continued, and scientists from around the world have now observed 10 black hole collisions and a merger of two binary neutron stars using LIGO and the European-based Virgo gravitational wave detector. 

Catalog of Coalescing Cosmic Objects

The records of these cataclysmic cosmic events, including four black hole observations disclosed for the first time, have been collected into a catalog released December 1 at the Gravitational Wave Physics and Astronomy Workshop held in College Park, Maryland. Production of the catalog suggests that gravitational wave astronomy will indeed offer astronomers a new way to view the secrets of the universe.

“The individual black hole detections previously announced allow us to confirm, after many years of searching, that gravitational wave astronomy is a feasible endeavor,” said James Alexander Clark, a research scientist in Georgia Tech’s Center for Relativistic Astrophysics (CRA) in the School of Physics and a member of the LIGO collaboration. “We now know that pairs of massive black holes exist and collide frequently enough for us to detect gravitational waves within a human lifetime. We also know that the instruments and analysis procedures we use are capable of detecting and characterizing gravitational wave sources and we have been able to start probing some basic features of the theory of general relativity.”

Astronomers do not have the luxury of repeating laboratory experiments to build confidence in their findings, Clark pointed out. “Instead, we rely on observing large samples of objects and phenomena spread throughout the universe. By building a ‘census’ of this population, we are rapidly learning more about how common these objects are, what their general properties are like, and about the diversity of black holes in the universe.”

Expanding the Observations

That census should expand more rapidly starting in April 2019 when LIGO begins its next observing run. The two instruments, one in Livingston, Louisiana, and the other in Hanford, Washington, are shut down periodically for upgrades to improve sensitivity. “By observing a larger sample of binary black hole sources, we are more likely to find systems with more extreme configurations that allow more stringent tests of our models — and of general relativity,” Clark added.

The new Gravitational Wave Catalog shows that gravitational waves from powerful cosmic phenomena arrive at the Earth almost once every 15 days of observation, noted Karan Jani, a postdoctoral fellow in the CRA and also a member of the LIGO collaboration. “Future releases will provide much stronger tests of Einstein’s theory of gravity, and help provide a better understanding of how black holes are formed in the universe.”

Data collected on the 10 black hole mergers describe objects that are as much as 100 times more massive than our own sun. Among the reports is a July 29, 2017, signal that represents the most distant, most energetic, and most massive black hole collision detected so far. That collision happened about five billion years ago — even before the birth of our sun — and released an amount of energy equivalent to converting almost five solar masses to gravitational radiation.

What We Learn from Black Hole Observations

Black holes are among the few objects in the universe massive and dense enough to produce gravitational waves that can be measured, said Sudarshan Ghonge, a CRA graduate student and also a member of the collaboration. But those measurements can be quite worthwhile.

“These waves have signatures that depend on the properties of the black holes from which they originated,” he said. “By measuring these waves, we can infer the masses, spin, sky location, and distance from us. It’s similar to how you can listen to a sound and roughly figure out where it’s coming from, how far away it is, and what’s causing it.”

LIGO works by observing infinitesimally small changes caused by gravitational waves passing through the Earth. The changes affect laser beams traveling through twin four-kilometer arms of the L-shaped observatories. The Hanford and Livingston facilities, separated by 1,865 miles, confirm the observations, as both facilities should detect the waves. Additional information comes from the Virgo facility in Italy.

Observing Runs Produce New Records 

From September 12, 2015, to January 19, 2016, during the first LIGO observing run since undergoing upgrades in a program called Advanced LIGO, gravitational waves from three binary black hole mergers were detected. The second observing run, which lasted from November 30, 2016, to August 25, 2017, yielded one binary neutron star merger and seven additional binary black hole mergers, including the four new gravitational wave events reported December 1. The new events are known as GW170729, GW170809, GW170818 and GW170823, in reference to the dates they were detected.

GW170814 was the first binary black hole merger measured by the three-detector network made possible by collaboration between LIGO and Virgo, and allowed for the first tests of gravitational wave polarization, which is analogous to light polarization. 

One of the new events, GW170818, detected by the global network formed by the LIGO and Virgo observatories, was very precisely pinpointed in the sky. The position of the binary black holes, located 2.5 billion light-years from Earth, was identified in the sky with a precision of 39 square degrees. That makes it the next-best localized gravitational wave source after the GW170817 neutron star merger.

The event GW170817, detected three days after GW170814, represented the first time that gravitational waves were observed from the merger of a binary neutron star system. What's more, this collision was seen in gravitational waves and light, marking an exciting new chapter in multi-messenger astronomy, in which cosmic objects are observed simultaneously in different forms of radiation.

Advancing Gravitational Wave Observation

“The release of four additional binary black hole mergers further informs us of the nature of the population of these binary systems in the universe and better constrains the event rate for these types of events,” said Caltech’s Albert Lazzarini, deputy director of the LIGO Laboratory.

"In just one year, LIGO and Virgo working together have dramatically advanced gravitational wave science, and the rate of discovery suggests the most spectacular findings are yet to come,” said Denise Caldwell, director of NSF's Division of Physics. "The accomplishments of NSF's LIGO and its international partners are a source of pride for the agency, and we expect even greater advances as LIGO's sensitivity becomes better and better in the coming year."

"The next observing run, starting in Spring 2019, should yield many more gravitational wave candidates, and the science the community can accomplish will grow accordingly,” said David Shoemaker, spokesperson for the LIGO Scientific Collaboration and senior research scientist in MIT’s Kavli Institute for Astrophysics and Space Research. “It’s an incredibly exciting time.” 

“It is gratifying to see the new capabilities that become available through the addition of Advanced Virgo to the global network,” said Jo van den Brand of Nikhef (the Dutch National Institute for Subatomic Physics) and VU University Amsterdam, who is the spokesperson for the Virgo Collaboration. “Our greatly improved pointing precision will allow astronomers to rapidly find any other cosmic messengers emitted by the gravitational wave sources.” The enhanced pointing capability of the LIGO-Virgo network is made possible by exploiting the time delays of the signal arrival at the different sites and the so-called antenna patterns of the interferometers.

The scientific papers describing these new findings, which are being initially published on the arXiv repository of electronic preprints, present detailed information in the form of a catalog of all the gravitational wave detections and candidate events of the two observing runs as well as describing the characteristics of the merging black hole population. Most notably, we find that almost all black holes formed from stars are lighter than 45 times the mass of the sun. Thanks to more advanced data processing and better calibration of the instruments, the accuracy of the astrophysical parameters of the previously announced events increased considerably.  

Added Georgia Tech professor Laura Cadonati, deputy spokesperson for the LIGO Scientific Collaboration, “These new discoveries were only made possible through the tireless and carefully coordinated work of the detector commissioners at all three observatories, and the scientists around the world responsible for data quality and cleaning, searching for buried signals, and parameter estimation for each candidate — each a scientific specialty requiring enormous expertise and experience.”

About LIGO and Virgo

LIGO is funded by NSF and operated by Caltech and MIT, which conceived and built the project. Financial support for the Advanced LIGO project was led by the NSF with Germany (Max Planck Society), the United Kingdom (Science and Technology Facilities Council) and Australia (Australian Research Council-OzGrav) making significant commitments and contributions to the project. More than 1,200 scientists from around the world participate in the effort through the LIGO Scientific Collaboration. A list of additional partners is available at http://ligo.org/partners.php.

The Virgo Collaboration consists of more than 300 physicists and engineers belonging to 28 different European research groups: six from Centre National de la Recherche Scientifique in France; 11 from the Istituto Nazionale di Fisica Nucleare in Italy; two in the Netherlands with Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with IFAE and the Universities of Valencia and Barcelona; two in Belgium with the Universities of Liege and Louvain; Jena University in Germany; and the European Gravitational Observatory, the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN and Nikhef. A list of the Virgo Collaboration can be found at http://public.virgo-gw.eu/the-virgo-collaboration/. More information is available on the Virgo website at www.virgo-gw.eu.

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NASA has navigated our solar system with spacecraft and landers, but still, our celestial neighbors remain vast frontiers, particularly in the search for life. Now, an alliance of researchers will accelerate the quest to find it.

The NASA Astrobiology Program has announced the establishment of the Network for Life Detection, NFoLD, which connects researchers to pursue the detection of life and clues thereof on our neighboring planets and their moons. NFoLD includes an oceanic research alliance led by the Georgia Institute of Technology. 

It is called Oceans Across Space and Time, OAST, and has received a $7 million NASA Astrobiology grant with the long-range goal of extracting secrets from present and past oceans on Mars, Jupiter’s icy moon Europa, and Saturn’s moon Enceladus. But OAST will also ramp up the study of the conditions that spawned first life in Earth’s oceans.

“With OAST, we finally hit the perfect mix of people, science questions, and supporting activities to really go after some of the most important unknowns in astrobiology,” said Britney Schmidt, OAST’s principal investigator and an assistant professor in Georgia Tech’s School of Earth and Atmospheric Sciences.

NFoLD is one of five new Research Coordination Networks that the NASA Astrobiology Program has announced. The other RCNs pull together research communities that include the study of early Earth and its chemistry, evolution, distant habitable worlds, and exoplanet systems.

Yellow submarine on Europa 

Oceans Across Space and Time could one day help NASA put a submarine on a rocket to Europa to look for life in the ocean beneath its ice crust. Or OAST could join NFoLD colleagues to help NASA explore parched Martian landscapes that once were oceans.

But the path to our space neighbors leads through studying Earth. Field and lab experiments on our planet will divulge more knowledge about chemical and biological evolutionary strategies so that researchers can develop instruments and methodology that reliably detect signs of life on other planets and moons.

"We don't yet have a slam-dunk measurement that we could make on another planet to definitively say ‘this is life,’” said Schmidt, who coordinates OAST and led the application efforts to establish it. “OAST’s main goal is to take a suite of technologies into the field on Earth to make measurements side-by-side while returning samples to the lab to understand.” 

Then, when that is very finely honed, send it aloft.

Crucial target practice 

One of NFoLD’s goals is to participate in future astrobiology space missions from the start so that they can successfully identify target spots on other planets or moons where signs of life could actually be detected if present.

"A major challenge for life detection is where on a given planet or moon to look for life,” said Jeff Bowman, deputy principal investigator of OAST and an assistant professor at Scripps Institution of Oceanography at UC San Diego. “The density of life on our own planet extends across several orders of magnitude. Look for life in the wrong place and Earth could appear lifeless.”

OAST’s team has the expertise to bridge earthly data and celestial goals.

Many of its 18 co-investigators and their teams have already explored biogeochemistry in our own planet’s eons-old rock record, in the atmosphere, the oceans, and the icecaps with an eye to extrapolating the data to other worlds. Other OAST researchers have helped design Mars probes or build robotic submarines intended to one day dive into Europa’s subsurface ocean to detect life or at least a hint of it.

“OAST researchers have expertise in detecting and characterizing life in a variety of harsh environments like the Antarctic, the deepest ocean trenches, and lakes with extreme chemistry and salinity,” Bowman said. “We will leverage this expertise to understand how life may be distributed in different ocean environmental extremes around the solar system.”

Diverse member institutions

OAST includes investigators from Scripps Institution of Oceanography at the University of California San Diego; the University of Kansas; Louisiana State University; the Massachusetts Institute of Technology; Stanford University; the Blue Marble Space Institute of Science; the University of Texas; Colgate University; the University of California, the University of Central Florida; the University of Auckland; York University; the University of Otago, and the New Zealand National Institute of Water and Atmospheric Research.

“I'm particularly proud of the high number of women and pre-tenure scientists we've engaged through our project,” said Schmidt. Five leaders in OAST are women, and 12 researchers are early career or pre-tenure. The project will also support graduate and undergraduate students as well as postdoctoral researchers through the NASA Postdoctoral Program.

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Also READ: Laughing Gas May Have Helped Warm Early Earth and Given Breath to Life

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The observations, made by the IceCube Neutrino Observatory at the Amundsen–Scott South Pole Station and in coordination with telescopes around the globe and in Earth’s orbit, help resolve a more than a century-old riddle about what sends subatomic particles such as neutrinos and cosmic rays speeding through the universe.

Since they were first detected over one hundred years ago, cosmic rays—highly energetic particles that continuously rain down on Earth from space—have posed an enduring mystery: What creates and launches these particles across such vast distances? Where do they come from? 

Because cosmic rays are charged particles, their paths cannot be traced directly back to their sources due to the magnetic fields that fill space and warp their trajectories. But the powerful cosmic accelerators that produce them will also produce neutrinos. Neutrinos are uncharged particles, unaffected by even the most powerful magnetic field. Because they rarely interact with matter and have almost no mass—hence their sobriquet “ghost particle”—neutrinos travel nearly undisturbed from their accelerators, giving scientists an almost direct pointer to their source. 

Two papers published July 13 in the journal Science have for the first time provided evidence for a known blazar as a source of high-energy neutrinos detected by the National Science Foundation-supported IceCube observatory. This blazar, designated by astronomers as TXS 0506+056, was first singled out following a neutrino alert sent by IceCube on September 22, 2017. 

“The evidence for the observation of the first known source of high-energy neutrinos and cosmic rays is compelling,” said Francis Halzen, a University of Wisconsin–Madison professor of physics and principal investigator for the IceCube Neutrino Observatory. 

“The era of multi-messenger astrophysics is here. Each messenger gives us a more complete understanding of the universe and important new insights into the most powerful objects and events in the sky,” said NSF Director France Córdova. “Such breakthroughs are only possible through a long-term commitment to fundamental research and investment in superb research facilities.”

A blazar is a galaxy with a super-massive, rapidly spinning black hole at its core. A signature feature of blazars is that twin jets of light and elementary particles, one of which is pointing to Earth, are emitted from the poles along the axis of the black hole’s rotation. This blazar is situated in the night sky just off the left shoulder of the constellation Orion and is about four billion light years from Earth. 

“Scientifically, this is very good news,” said Ignacio Taboada, an associate professor in Georgia Tech’s School of Physics and member of the Center for Relativistic Astrophysics also at Georgia Tech. As leader of the “Transients Science Working Group” within IceCube, he oversaw all the studies that inquired on the correlation TXS 0506+056’s gamma ray flare and the neutrino alert of September 22, 2017. “For years, we’ve had a long list of potential sources for high-energy neutrinos. Now we have a specific source – blazars – that we can look at very carefully.” 

See the full feature article and video

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The project will miniaturize, space qualify and test a laser communications transceiver that could dramatically expand the bandwidth available for downlinking information from the growing number of satellites – and future constellations of space vehicles – in low Earth orbit. Xenesis has licensed the technology from NASA’s Jet Propulsion Laboratory (JPL), and will work with Georgia Tech and JPL to mature it for use as a primary communication system for satellites as small as CubeSats.

“We expect to significantly add to the total bandwidth of information that we can get down from space, and the more bandwidth we have, the more information we can exchange and the more value we can get from satellite networks,” said Brian Gunter, an assistant professor in Georgia Tech’s Daniel Guggenheim School of Aerospace Engineering who will be leading the project.

Gunter’s lab has experience with small satellites, and will apply that expertise to the project with Xenesis – which signed a $1.2 million contract on June 14 to support the work. Georgia Tech’s contribution will be to miniaturize the original JPL technology, update the control software, space qualify all the hardware and test the improved system from space – likely from the International Space Station.

“With all of the satellites that are going into space, everything from CubeSats to major satellites, there is more information being generated than can ever be downloaded,” said Dennis Poulos, chief technology officer at Xenesis. “Most of today’s systems depend on radio frequency downlinks, and there is just a limited amount of bandwidth available for use.”

Laser-based systems can expand that bandwidth to beyond 10 gigabits per second, Poulos said. In addition to boosting bandwidth, optical systems can use smaller antennas, use power more efficiently, and provide better data security.

Mark LaPenna, CEO of Xenesis, compared the benefits of the planned space-based network to the jump in performance from terrestrial dial-up connections of the 1990s to today’s high-speed broadband services.

"Xenesis recognizes the need for a global communications revolution, and we plan to empower space with an optical product called XenHub,” LaPenna said. “Through this architecture, any company, mission or global operator on the ground or in space, will be able to compete on a level playing field for the first time since Sputnik."

The laser communications transceiver developed by JPL consists of two components: (1) an optics module that includes a five-centimeter telescope, two-axis gimbal, monitoring sensors and thermal control system, and (2) an electronics module with a transmitter, processor, controllers and power conditioning systems. 

Though it is subject to interference from clouds, the laser system will benefit from producing a narrow beam that can travel farther than comparable radio-frequency transmissions at the same power level. 

The initial focus will be space-to-ground communication, though the system could also be used for cross-linking communication between satellites. The small antenna size is also more suitable to the small-form satellites envisioned for future constellations that may include thousands of spacecraft.

“Once we can show that this works from space to ground, that will demonstrate that the technology can survive the harsh environment of space, and allow us continue the development of the transceiver for commercial use,” Gunter added. “This has the potential to open up a range of new capabilities, including the ability to provide high-volume data services to anywhere in the world.”

In Georgia Tech’s School of Aerospace Engineering, the contract will support three or four graduate students, a postdoctoral researcher, and a group of undergraduate students, Gunter said. “This will be a major satellite project for our lab, and we look forward to advancing the technology with our collaborators.”

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According to a new study, the answer is the microbiome – the community of bacteria found in homes, offices and aircraft cabins. Believed to be the first to comprehensively assess the microbiome of aircraft, the study found that the bacterial communities accompanying airline passengers at 30,000 feet have much in common with the bacterial communities surrounding people in their homes and offices.

Using advanced sequencing technology, researchers from the Georgia Institute of Technology and Emory University studied the bacteria found on three components of an airliner cabin that are commonly touched by passengers: tray tables, seat belt buckles and the handles of lavatory doors. They swabbed those items before and after ten transcontinental flights and also sampled air in the rear of the cabin during flight. 

What they found was surprisingly unexciting.

“Airline passengers should not be frightened by sensational stories about germs on a plane,” said Vicki Stover Hertzberg, a professor in Emory University’s Nell Hodgson Woodruff School of Nursing and a co-author of the study. “They should recognize that microbes are everywhere and that an airplane is no better and no worse than an office building, a subway car, home or a classroom. These environments all have microbiomes that look like places occupied by people.”

The results of the FlyHealthy™ study were reported June 6, 2018, in the journal Microbial Ecology. In March, the researchers reported on a separate part of the study that examined potential routes for transmitting certain respiratory viruses – such as the flu – on commercial flights.

Given the unusual nature of an aircraft cabin, the researchers hadn’t known what to expect from their microbiome study. On transcontinental flights, passengers spend four or five hours in close proximity breathing a very dry mix of outdoor air and recycled cabin air that has been passed through special filters, similar to those found in operating rooms. 

“There were reasons to believe that the communities of bacteria in an aircraft cabin might be different from those in other parts of the built environment, so it surprised me that what we found was very similar to what other researchers have found in homes and offices,” said Howard Weiss, a professor in Georgia Tech’s School of Mathematics and the study’s corresponding author. “What we found was bacterial communities that were mostly derived from human skin, the human mouth – and some environmental bacteria.”

The sampling found significant variations from flight to flight, which is consistent with the differences other researchers have found among the cars of passenger trains, Weiss noted. Each aircraft seemed to have its own microbiome, but the researchers did not detect statistically significant differences between preflight and post-flight conditions on the flights studied.

“We identified a core airplane microbiome – the genera that were present in every sample we studied,” Weiss added. The core microbiome included genera Propionibacterium, Burkholderia, Staphylococcus, and Strepococcus (oralis).

Though the study revealed bacteria common to other parts of the built environment, Weiss still suggests travelers exercise reasonable caution. “I carry a bottle of hand sanitizer in my computer bag whenever I travel,” said Weiss. “It’s a good practice to wash or sanitize your hands, avoid touching your face, and get a flu shot ever year.”

This new information on the aircraft microbiome provides a baseline for further study, and could lead to improved techniques for maintaining healthy aircraft.

“The finding that airplanes have their own unique microbiome should not be totally surprising since we have been exploring the unique microbiome of everything from humans to spacecraft to salt ponds in Australia. The study does have important implications for industrial cleaning and sterilization standards for airplanes,” said Christopher Dupont, another co-author and an associate professor in the Microbial and Environmental Genomics Department at the J. Craig Venter Institute, which provided bioinformatics analysis of the study’s data.

The 229 samples obtained from the aircraft cabin testing were subjected to 16S rRNA sequencing, which was done at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama. The small amount of genetic material captured on the swabs and air sampling limited the level of detail the testing could provide to identifying genera of bacteria, Weiss said. The extensive bioinformatics, or sequence analysis, was carried out at the J. Craig Venter Institute in La Jolla, Calif.  

In the March 19 issue of the journal Proceedings of the National Academy of Sciences, the researchers reported on the results of another component of the FlyHealthy™ study that looked at potential transmission of respiratory viruses on aircraft. They found that an infectious passenger with influenza or other droplet-transmitted respiratory infection will most likely not transmit infection to passengers seated farther away than two seats laterally and one row in front or back on an aircraft. 

That portion of the study was designed to assess rates and routes of possible infectious disease transmission during flights, using a model that combines estimated infectivity and patterns of contact among aircraft passengers and crew members to determine likelihood of infection. FlyHealthy™ team members were assigned to monitor specific areas of the passenger cabin, developing information about contacts between passengers as they moved around.

Among next steps, the researchers would like to study the microbiome of airport areas, especially the departure lounges where passengers congregate before boarding. They would also like to study long-haul international flights in which passengers spend more time together – and are more likely to move about the cabin.

In addition to those already mentioned, the paper’s authors include Josh L. Espinoza and Karen Nelson of the J. Craig Venter Institute, Shawn Levy of the HudsonAlpha Institute for Biotechnology, and Sharon Norris of The Boeing Company.

This work was supported by contract 2001-041-1 between the Georgia Institute of Technology and The Boeing Company.

CITATION: Howard Weiss, et al., “The Airplane Cabin Microbiome,” (Microbial Ecology, 2018).  https://link.springer.com/article/10.1007/s00248-018-1191-3

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With guidance from the GTRI researchers, the project will improve usability of the mission planning software tools, creating a more consistent and intuitive screen design that’s easier to learn and more logical to follow. This effort could benefit all Department of Defense (DoD) agencies for collaborative mission planning.

“We are working with Navy and Marine Corps aviators to identify areas in mission planning where work-flow can be streamlined, reducing the time required to mission plan,” said Marcia Crosland, project director for GTRI’s Joint Mission Planning System (JMPS) User Interface Design and Usability efforts. “Our task has been to define the user interface concepts and decision-making tools to help reduce the time required for mission planning. We’ve created detailed designs and specifications to direct current and future development of mission planning systems.”

Mission planning needs to support the ability to collaboratively plan missions involving multiple aircraft but currently does not have that capability. The planning challenge can be quite complex, involving multiple targets, ground-based threats, different aircraft types and a variety of weapons systems. The most complex part of the process is often done by multiple pilots using whiteboards, paper, and spreadsheets to combine relevant information, consider alternatives, and reveal complicated issues.

Information from the whiteboarding process is then entered into the software system, which produces the mission plans that go on board the aircraft. The GTRI human factors team realized that supporting these whiteboarding activities in the mission planning system could accelerate the mission planning process, and they created new designs to support this functionality. 

“We are making recommendations for how the Navy can streamline the process and move it all into the digital world to eliminate the paper and whiteboard processes,” said Crosland. “That will allow aircrews to plan a mission more efficiently, reducing the time required and potentially highlighting places where automated decision-making tools could be brought into the process.”

She added: “We tried to understand the tasks of the user and therefore how the workflow could be streamlined. From that, we designed user interfaces that better implement the tasks, and we developed a style guide to help the DoD software programmers who were implementing it.”

At each iteration of the process, prototype interface designs were evaluated with experts. In some cases, those experts visited the GTRI team in Atlanta to review and discuss the designs.

“We took them through each of the screens to find out what is intuitive to them and what is not,” Crosland said. “We did this multiple times with different user groups to make sure we had a good set of interface concepts. In this work, it’s critical to involve the intended users of the system.”

The GTRI team has applied lessons learned from a variety of domains – desktop and web design, and commercial and military applications. For instance, shortening the distance between buttons on a screen, reducing the number of clicks necessary for a task, consolidating screens, and providing a consistent workflow direction make a digital system easier and faster to use – whether it’s a website or mission planning system. 

“We want to make the system a companion for the aircrews so they consider it a partner in these critical processes,” she added. In one case, the researchers were able to consolidate nine separate screens, each with different tabs, into a single screen.

“At the root of all user interface design, whether it’s web or something else, is creating a time-efficient task that is intuitive so using it takes less time and less training and creates fewer errors,” Crosland said. “If you can cut down on errors because users understand the system, it will make the system more efficient.”

GTRI’s Human Systems Engineering Branch (HSEB) has been in operation for more than 30 years to help improve the interaction between warfighters and the technologies they use. 

“We have significant experience in understanding the domains of mission planning and mission execution, and the components that make technology easier to use,” Crosland said. “We use established design standards customized for a particular format, whether it’s a mobile tablet or standard computer.”

In addition to Crosland, the GTRI team includes more than 20 people. The leadership component includes Tommer Ender, director of GTRI’s Electronic Systems Laboratory (ELSYS); Adam McCorkle and J.D. Fassett, both associate directors in ELSYS; Debra Jones, head of ELSYS’s HSEB, and C.J. Hutto, associate branch head for HSEB.

The project’s analysis and design team has included Buddy Ray, Stuart Michelson, Andrew Baranak, Vlad Pop, Liz Weldon, Chandler Price, Courtney Crooks, Chris Hale, Mike Fitzpatrick, Robert Kempf; technical advisor John Huggins; HCI graduate students Catherine Johnson, Sarah Brooks and Rachel Chen, undergraduate students Megan Eberle and Spencer Frum; and other GTRI subject matter experts.

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Research News
Georgia Institute of Technology
177 North Avenue
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Media Relations Contacts: Georgia Tech: John Toon (jtoon@gatech.edu) (404-894-6986) or Emory University: Melva Robertson: (melva.robertson@emory.edu) (404-416-0822) or Allison Caughey (allison.caughey@emory.edu) (404-727-1225).

And they howled with laughter when they saw a car in space.

“It was awesome! It was unbelievable to see something so historic,” said Swapnil Pujari.

He was one of 30 or so Georgia Tech aerospace engineering students who crowded into a lab in the Engineering Science and Mechanics Building Tuesday afternoon to watch a livestream of SpaceX’s first test flight of the world’s most powerful rocket — the Falcon Heavy.

From the sound in the room, the launch was an unquestionable success.

“I got goosebumps when I saw the two boosters land at the same time,” said William Jun, a fourth-year undergraduate in the Daniel Guggenheim School of Aerospace Engineering. “I feel like I’ve witnessed the beginning of a new era.”

It’s hard to imagine what he’ll feel the next time the Falcon Heavy launches.

Tuesday’s launch only carried one piece of cargo, a red Tesla Roadster that is expected to orbit the sun for the next billion years. The next Heavy rocket will be stuffed with satellites. One of them is scheduled to be Prox-1, a 154-pound, rectangular-shaped metal box that was built and tested by Jun, Pujari and other Georgia Tech students. It’s the first spacecraft built on campus that will fly in space.

“This is the part of the space industry that we live for,” said Professor Glenn Lightsey, who watched the launch with the students. “Ultimately, there is a day when you find out if the thing you’ve thought about and planned for actually works or not. Today (Tuesday) it happened for SpaceX. Six months from now, it will happen for us at Georgia Tech.”

Prox-1 is a 24” by 22” by 12” satellite that will deploy a smaller spacecraft, LightSail 2, which will attempt the first controlled solar sail flight in Earth orbit.

As that sail unfurls, Prox-1 will move and observe LightSail from a short distance and acquire images of the glimmering structure in action. Georgia Tech will serve as mission control.

“Our students are going to have their hardware in space, making measurements and sending their data back to Earth,” said Lightsey. “This is a really unique experience that wasn’t even possible before this century. It’s a new way of doing things in STEM (science, technology, engineering and mathematics) education.”

Prox-1 is currently at the Air Force Research Lab in New Mexico, undergoing a series of tests to make sure the satellite can withstand the rugged, violent ride inside the Falcon Heavy. It’s one of the final pre-flight steps for a six-year project that has included more than 400 Georgia Tech students. From there it will be shipped to Florida and await an official launch date from SpaceX.

Although they enjoyed the experience together for Tuesday’s launch, don’t expect many of the same students to gather on campus to watch Prox-1 blast into space.   

“Oh, I will be in Florida for sure!” said Pujari.

The aerospace engineering graduate will now attend flight school in Pensacola, Florida.

“It’s a lifelong dream come true,” he said. “I’m excited to serve my country as a naval aviator. And to me it’s just the best of both worlds because I get to serve my country, but I’m going to be serving my country doing something pretty awesome.”

Freels said his education at Georgia Tech was possible because of the ROTC (Reserve Officers’ Training Corps) scholarship. As a midshipman, he was in charge of the Navy ROTC battalion for a semester.

He joined the Ramblin’ Reck Club sophomore year and served as the group’s president this year. The club maintains many of the campus’ most beloved traditions, including the Freshman Cake Race, the Mini 500 and the upkeep and display of the Reck, a 1930 Ford Model A Sport Coupe.  

“My favorite thing about Georgia Tech is how close we are to our traditions.”

NASA astrobiologists from the Georgia Institute of Technology have developed a comprehensive new model that shows how planetary chemistry could make that happen. The model, published in a new study in the journal Nature Geoscience, was based on a likely scenario on Earth three billion years ago and was actually built around its possible geological and biological chemistry.

The sun produced a quarter less light and heat then, but Earth remained temperate, and methane may have saved our planet from an eon-long deep-freeze, scientists hypothesize. Had it not, we and most other complex life probably wouldn’t be here today.

The new model combined multiple microbial metabolic processes with volcanic, oceanic and atmospheric activities, which may make it the most comprehensive of its kind to date. But while studying Earth’s distant past, the Georgia Tech researchers aimed their model light-years away, wanting it to someday help interpret conditions on recently discovered exoplanets.

The researchers set the model’s parameters broadly so that they could apply not only to our own planet but potentially also to its siblings with their varying sizes, geologies, and lifeforms.

Earth and its siblings

“We really had an eye to future use with exoplanets for a reason,” said Chris Reinhard, the study’s principal investigator and an assistant professor in Georgia Tech’s School of Earth and Atmospheric Sciences. “It’s possible that the atmospheric methane models that we are exploring for the early Earth represent conditions common to biospheres throughout our galaxy because they don’t require such an advanced stage of evolution like we have here on Earth now.”

Reinhard and first author Kazumi Ozaki published their Nature Geoscience paper on December 11, 2017. The research was supported by the NASA Postdoctoral Program, the Japan Society for the Promotion of Science, the NASA Astrobiology Institute and the Alfred P. Sloan Foundation.

Previous models have examined the mix of atmospheric gases needed to keep Earth warm in spite of the sun’s former faintness, or studied isolated microbial metabolisms that could have made the needed methane. “In isolation, each metabolism hasn’t made for productive models that accounted well for that much methane,” Reinhard said.

The Georgia Tech researchers synergized those isolated microbial metabolisms, including ancient photosynthesis, with geological chemistry to create a model reflective of the complexity of an entire living planet. And the model’s methane production ballooned.

“It’s important to think about the mechanisms controlling the atmospheric levels of greenhouse gases in the framework of all biogeochemical cycles in the ocean and atmosphere,” said first author Ozaki, a postdoctoral assistant.

Also READ: The Earth is not a lab beaker; it’s a shifty, humongous lab

Carl Sagan and the faint Sun

The Georgia Tech model strengthens a leading hypothesis that attempts to explain a mystery called the “faint young Sun paradox” pointed out by iconic late astronomer Carl Sagan and his Cornell University colleague George Mullen in 1972.

Astronomers noticed long ago that stars burned brighter as they matured and weaker in their youths. They calculated that about two billion years ago, our sun must have shone about 25 percent fainter than it does today.

That would have been too cold for any liquid water to exist on Earth, but paradoxically, strong evidence says that liquid water did exist. “Based on the observation of the geological record, we know that there must have been liquid water,” Reinhard said, “and in some cases, we know that temperatures were similar to how they are today, if not a little warmer.”

Sagan and Mullen postulated that Earth’s atmosphere must have created a greenhouse effect that saved it. Back then, they suspected ammonia was at work, but chemically, that idea proved less feasible.

“Methane has taken a lead role in this hypothesis,” Reinhard said. “When oxygen and methane enter the atmosphere, they chemically cancel each other out over time in a complex chain of chemical reactions. Because there was extremely little oxygen in the air back then, it would have allowed for methane to build up much higher levels than today.”

Iron, and rust photosynthesis

At the core of the model are two different types of photosynthesis. But three billion years ago, the dominant type of photosynthesis we know today that pumps out oxygen may not have even existed yet.

Instead, two other very primitive bacterial photosynthetic processes likely were essential to Earth’s ancient biosphere. One transformed iron in the ocean into rust, and the other photosynthesized hydrogen into formaldehyde.

“The model relied on lots of volcanic activity spewing out hydrogen,” Ozaki said. Other bacteria fermented the formaldehyde, and other bacteria, still, turned the fermented product into methane.

The two photosynthetic processes served as the watch spring of the model’s clockwork, which pulled in 359 previously established biogeochemical reactions spanning land, sea and air.

3,000,000 runs and raging methane

The model was not the type of simulation that produces a video animation of Earth’s ancient biogeochemistry. Instead, the model mathematically analyzed the processes, and the output was numbers and graphs.

Ozaki ran the model more than 3 million times, varying parameters, and found that if the model contained both forms of photosynthesis operating in tandem, that 24 percent of the runs produced enough methane to create the balance needed in the atmosphere to maintain the greenhouse effect and keep ancient Earth, or possibly an exoplanet, temperate.

“That translates into about a 24 percent probability that this model would produce a stable, warm climate on the ancient Earth with a faint sun or on an Earth-like exoplanet around a dimmer star,” Reinhard said. “Other models that looked at these photosynthetic metabolisms in isolation have much lower probabilities of producing enough methane to keep the climate warm.”

“We’re confident that this rather unique statistical approach means that you can take the basic insights of this new model to the bank,” he said.

Other explanations for the “faint young Sun paradox” have been more cataclysmic and perhaps less regular in their dynamics. They include ideas about routine asteroid strikes stirring up seismic activity thus resulting in more methane production, or about the sun consistently firing coronal mass ejections at Earth, heating it up. 

Also READ: Some good news on climate change and methane

The research was co-authored by Eiichi Tajika, Peng K. Hong and Yusuke Nakagawa of the University of Tokyo. The research was supported by the NASA Postdoctoral Program, the Japan Society for the Promotion of Science (grant 25120006), the NASA Astrobiology Institute (grant NNA 15BB03A) and the Alfred P. Sloan Foundation (grant FR-2015-65744). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of those sponsors

The U.S. Naval Air Systems Command (NAVAIR), Naval Air Warfare Center - Aircraft Division (NAWCAD) and the Georgia Tech Research Institute (GTRI) are working to address that challenge through a new effort – dubbed IMPAX (Innovation and Modernization Patuxent River) – that aims to accelerate the transfer of new technology to meet U.S. Navy and U.S. Marine Corps needs. IMPAX staff members are empowered to work outside the standard acquisition process to find, develop, and prototype new technology more quickly.

IMPAX was launched in 2017 as an initiative of Rear Admiral Mark Darrah, program executive officer for Unmanned Aviation and Strike Weapons at NAVAIR, by working closely with the Technology Transfer Office at NAWCAD. The first initiative with the Navy is to identify technology that will help integrate unmanned aerial vehicles into air control systems by providing miniaturized identification friend or foe (IFF) systems. IFF systems are already used in piloted aircraft, but the much smaller unmanned aircraft lack the space or power for conventional systems.

“Traditionally the Department of Defense (DoD) has been limited in the means and speed at which it could bring new technologies to the warfighter,” said Rob “Radar” Winston, a GTRI principal research engineer who directs the IMPAX program near Pax River Naval Air Station in Maryland. “Our adversaries aren’t constrained by cumbersome procurement rules and regulations. Through this effort, we want to ensure that our nation’s warfighters get the best technology in the shortest time.”

IMPAX is empowered to seek out technology from sources the government doesn’t usually work with. These can include small- and medium-sized businesses, companies that don’t traditionally work with the military or bid on billion-dollar DoD procurements. Winston and his team work on the Navy’s behalf, matching warfighter needs with technology that may already exist – or that can be developed to meet the needs. 

The relationship between GTRI and NAVAIR’s Naval Air Warfare Center Aircraft Division (NAWCAD) is known as a partnership intermediary agreement (PIA). Such agreements allow non-federal government intermediaries to coordinate and solicit non-traditional science and technology sources and to bring forth ideas from parties not usually able to contribute directly to military solutions. 

“This is the first PIA specifically designed for the Navy to spin technology into naval aviation,” Winston explained. “We are looking for technology in industry, academia, and other government agencies that can be brought into the DoD very rapidly. If somebody is already working on something that the Navy needs, we can bring them together quickly. We are not just working for the government, but as a team member on the government’s behalf as a trusted partner.”

In one aspect, IMPAX team members will serve as technology scouts, scouring many sources of information to locate technologies of interest. They’ll be readily approachable, and won’t require extensive paperwork from companies and others wanting to pitch their technology for potential military applications. The overall activities will be directed by a joint GTRI/NAWCAD/NAVAIR team. 

“If an individual or company has a great idea but they have never worked with the government before, that barrier to entry is very tall now,” he said. “They don’t know who to talk with, how to get involved in a program, or even how to get through the front gate of a military facility. We are going to be able to talk with these people to assess what they can contribute to the warfighter and do it all outside the gate and without the customary barriers.”

DoD agencies have their own research laboratories to help develop new technology, of course, but Winston’s group will tap other sources of innovation. For technology that’s promising but not quite ready for DoD use, IMPAX will fund brief research and development (R&D) initiatives – as short as three or four months – to determine whether a technology is worth pursuing. Pathways from there could include the traditional agency R&D laboratories.

“The purpose is to run these programs very quickly, and also to fail things fast with a minimum of investment in resources or time if they aren’t working out,” he said. “We can start a technology development program at any time, and it can be any technology of interest to the fleet.” 

Each technology development program will be monitored by a subject matter expert and a director from GTRI. They will keep a close eye on program progress, help faltering ones, shut down ones that aren’t making progress or add team members and expertise to promising ones.

The IMPAX team will also be able to assemble packages of different technologies to meet specific needs, efforts known as mash-ups. 

“Traditional programs do little to encourage the collision of ideas between different organizations, people, and technologies,” Winston said. “We’re here to help companies and organization work together to address the need with minimal barriers to innovation.”

The IMPAX initiative won’t change how major weapons systems are acquired, but could affect how those systems are updated over time to retain their effectiveness as new technologies rapidly enter the marketplace. 

“IMPAX is going to enable technology that will keep these big platforms operationally relevant over a longer period of time,” Winston explained.

The IFF capability for unmanned systems is just one example of an ongoing IMPAX project. Another initiative is looking at the use of augmented reality to support maintenance and training programs. By combining 3-D computer-aided design files with mixed reality glasses, the technology could help maintainers identify a problem, locate components hidden within an aircraft, and train new personnel more quickly.

“Technology already exists for these projects, but it would take a long time to actually get them to the fleet using traditional acquisition timelines,” said Winston. “We can help develop the capability, get it to the Navy who can then get it out to the warfighter quickly. We’ll run as fast as we can with a project and give our warfighters the edge by getting the latest technology to them – today.”

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Media Relations Contact: John Toon (404-894-6986) (jtoon@gatech.edu).

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That's how researcher Michael Day described the recent DARPA Service Academies Swarm Challenge, which pitted mixed groups of up to 25 highly autonomous unmanned aerial vehicles (UAVs) on a side against one another in a next-generation version of the traditional "capture the flag" game. The friendly live-fly competition involved student teams from the U.S. Air Force Academy, the U.S. Military Academy, and the U.S. Naval Academy, with each team developing and testing their own innovative offensive and defensive tactics to conduct mock swarm-on-swarm battles.

Day, a research scientist at the Georgia Tech Research Institute (GTRI), co-led the support efforts required to stage the competition, working with the teams to help them operate the swarms, which included fixed-wing, propeller-driven Marcus UAV Zephyr aircraft and DJI Flame Wheel quadcopters. GTRI coached the teams and shared its simulation software to help the competitors develop tactics for both protecting their own space and invading another team’s base. Warren Lee, branch head for GTRI’s Unmanned Flight Operations, co-led the project with Day.

The competition was sponsored by the Defense Advanced Research Projects Agency (DARPA), which has a history of fostering competition to help advance cutting-edge technology. In addition to GTRI, the event was supported by the Naval Postgraduate School (NPS) and the Space and Naval Warfare Systems Command (SPAWAR). It was held in April 2017 at Camp Roberts, a California Army National Guard facility.

The vehicles were adapted from foam-wing radio-control hobbyist aircraft and rotorcraft designed to carry cameras. But these aerial vehicles were modified with computers that contained sophisticated autopilots, as well as separate computers that helped them coordinate with swarm teammates, locate opponents, and conduct offensive and defensive maneuvers — including aerial dogfights. 

But the tactics weren’t the only thing tested at the competition.

“A big challenge for us was logistical,” said Day. “Getting this many aircraft ready to fly and launched safely in the brief window of time we had required a lot of preparation.”

The competition was built on lessons learned from an earlier event that pitted GTRI researchers against colleagues from the Naval Postgraduate School. That competition involved swarms composed of ten highly autonomous unmanned aircraft — all of them the same type — on each team.

Building the Aircraft

Starting in August 2016, GTRI researchers began building and testing the aircraft slated for use in the competition. They built them in batches, assembling the basic vehicles, installing the electronics and then testing them. Each of the fixed-wing aircraft had an autopilot, flight computer, two radios, a GPS receiver, and avionics to operate the flight controls. 

GTRI has years of experience incorporating autonomy into unmanned air vehicles, having conducted swarm research projects for agencies that include DARPA and the Office of Naval Research. 

“Our operators and integrators are experienced, and we’ve gone through the highs and lows in terms of successes and failures,” said Lee. “We felt extra pressure in this program to make sure that each and every aircraft was ready to fly so the teams could fully trust them and focus their efforts on the competition.”

In all, Lee’s group, which included senior research engineer Gary Gray and research engineer Evan Hammac, built 144 aircraft, a mix of the foam-wing and quadcopter models. They were delivered to the service academies in time for students to become familiar with the aircraft operation. Members of GTRI’s UAV team visited each of the academies twice to work with the cadets and midshipmen.

“It was exciting and very rewarding to be able to work with the students on this project,” said Day. “They have a lot of demands on their time from their studies, so it was really hands-on and ambitious.”

In addition to building and testing the aircraft and working with the students, GTRI also built seven NPS-designed launchers for the Zephyrs, which have a 54-inch wingspan. The launchers get the aircraft up to flight speed, accelerating the launch process — which was part of the overall competition.

“To get them all into the air, you can’t spend more than about 30 seconds with each aircraft,” noted Day, who was part of the GTRI group that supported the competition on the ground at Camp Roberts. 

“When you have 30 aircraft in the sky, it’s very different from when you only have five or 10,” he said. “There’s a higher level of stress because there are a lot more tasks to manage. We had a lot of lessons from our flight operations that we were able to share with the students.”

Earlier, Lee’s team built 65 Skywalker aircraft for the Low-Cost UAV Swarming Technology (LOCUST) program supported by the Office of Naval Research (ONR).

Flying in Simulation

In developing swarm tactics, GTRI relies heavily on simulation to prepare for actual flight tests. Computer time to run simulations is much less expensive than flying time, and allows for hundreds or thousands of test runs in the time that would be required for a single flight test.

“We can do testing in our laboratory using a variety of simulation tools and have the ability to run thousands of different scenarios, look at the results of different types of engagements, and then use machine learning techniques to hone in on new swarm-versus-swarm tactics,” said Don Davis, division chief of GTRI’s Robotics and Autonomous Systems Division. “In many cases, the simulation leads us to ideas we wouldn’t have thought of if we had been bound by human experience in this area.”

Among the tools used by the service academy teams was SCRIMMAGE (Simulating Collaborative Robots in a Massive Multi-Agent Game Environment), developed by GTRI researchers led by senior research engineer Kevin DeMarco. SCRIMMAGE allows the interactions of tens, hundreds, or even thousands of air vehicles to be studied simultaneously. The system’s interface was designed to be familiar to anyone who has played video games.

“We can run the simulations faster than real time, so we can apply modern techniques that require much more data,” said DeMarco. “We developed SCRIMMAGE to allow users to see exactly how a new algorithm is affecting an aircraft’s flight maneuvers. We can run it on high-performance computing clusters to conduct millions of simulations and then have our machine-learning algorithms process that data to improve the algorithms.”

The simulator doesn’t run on the real aircraft, but does use the aircraft control software as part of its testing.

One of the combat tactics developed on SCRIMMAGE and used by the Service Academies Swarm Challenge aircraft is called “Greedy Shooter.” Each UAV equipped with the software can locate the nearest enemy and go after it. The algorithm doesn’t rely on collaboration among air vehicles, so multiple aircraft might attack the same enemy.

“In SCRIMMAGE, we have shown that you get a 50 percent success rate with this,” said DeMarco.

But another algorithm developed by senior research scientist Charles Pippin allows the air vehicles to allocate tasks, much as a human team may divide up the work that needs to be done on a project. “The vehicles can negotiate among themselves and decide who will be assigned to each target. There is no specific leader, but in a decentralized way, the aircraft make those decisions,” DeMarco explained.

In the Swarm Challenge, each of the vehicles had information about all of the other vehicles, but in real combat situations, that wouldn’t be the case. SCRIMMAGE is helping GTRI researchers determine how much information is needed to gain improvements from the task allocation model.

GTRI researchers are also comparing the swarm strategies against a legacy system — the old-fashioned “wingman” approach in which two aircraft work as a team. That simple approach has advantages over more complicated algorithms even when computers are tracking all the air vehicles.

“Lots of agents running simple algorithms can make swarms look more intelligent than they actually are,” DeMarco said. “Our hypothesis is that by being able to solve the two-versus-two challenge, we may be able to extend what we learn to a swarm.”

The Competition and Outcome

At the three-day competition, service academy teams faced off against each other inside a “Battle Cube,” a three-dimensional airspace 500 meters on a side and 78 meters above the ground. Each team was given 20 fixed-wing UAVs and 20 quadcopters and, under the Challenge rules, could select a mix of 25 vehicles (with five in reserve, for a total of 30) for each of two 30-minute battle rounds.

Each team had to defend its flag — a large, inflatable ground target — while trying to score the most points. Points could be awarded in three ways: physically landing a UAV on the opponent’s flag, simulated firing on an opponent’s UAV, and launching as many aircraft as possible.

The U.S. Naval Academy was declared the winner of the competition. (Full information about the event is available at www.darpa.mil/news-events/2017-05-11).

In addition to helping advance swarm tactics, the competition also helped the next generation of Air Force, Army, and Navy leaders get a head start on future swarm technology.

“This competition wasn’t as much about who won and who lost as it was about offering hands-on insights about this quickly evolving and increasingly important technology,” said Davis. “GTRI is pleased to help train and equip the next generation of warfighters. Together, we showed that it is possible to get swarms of vehicles in the air and into mock combat against each other.”

Among the lessons learned was the importance of rapidly launching the aircraft. Davis said the team able to get into the air first had an advantage over others. The competition also stretched the wireless networks used to communicate among the aircraft, and that will need improvement in the future.

“The biggest surprise to me was how well everything worked and how well the swarms operated,” Davis said. “This is another step in developing the knowledge and experience required to use UAV swarms in the field. There’s a lot more that needs to be done, but we’re making progress.”

In the future, highly autonomous vehicles could ultimately find uses throughout the military.

“UAVs will be extending the capabilities of the warfighter,” Davis said. “I don’t think we should expect swarms of UAVs to primarily just replace people. I think it’s appropriate to think of UAVs as tools that warfighters can use to address a threat.”

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“We’re really excited about the partnership with Delta,” said Georgia Tech President G.P. “Bud” Peterson. “This facility is a little different. Our students, faculty, staff and researchers will be able to develop products, and it provides Delta an opportunity to collaborate with its partners.”

Made possible by a $3 million gift from the Delta Air Lines Foundation, the facility was designed to be an integrated physical and cyber manufacturing technology testbed as well as a demonstration and teaching facility. The Advanced Manufacturing Pilot Facility (AMPF) will be a flagship component of the Georgia Tech Manufacturing Institute as a location where early-stage concepts can go from idea to reality.

“Over the last two years, inspired by insights gained from our close collaboration in manufacturing research with industry partners, faculty members from the schools of Mechanical Engineering, Aerospace Engineering, Industrial and Systems Engineering, Materials Science and Engineering, and Interactive Computing came together to define the requirements for a learning and research facility that will provide the foundation for future innovations in digital manufacturing,” said Don McConnell, Georgia Tech’s vice president of Industry Collaboration.

Peterson said the building had been part of the Atlantic Steel plant and before it was converted to house Delta’s AMPF and Boeing’s Manufacturing Development Center, the building had served as a warehouse for Georgia Tech’s Housing department to store and repair furniture for residence halls and on-campus apartments.

“Georgia Tech is a world-class institute, and we’re really blessed to have you in our hometown,” said Gil West, senior executive vice president and chief operating officer for Delta.

Back on May 2, Delta and Georgia Tech held a ribbon cutting for an innovation center called “The Hangar” in Tech Square, which is now home to 20 such innovation centers. The AMPF establishes Georgia Tech as a national leader in advanced manufacturing.

Aerospace manufacturers relied heavily on composite materials for this latest generation of passenger jets. While composite parts have been used for decades, today as much as half of all airplane components can be made of composites, including major structures such as wings and the fuselage.

For airlines, the shift to composites creates an opportunity to rethink the repair and maintenance operations needed to keep jets in top form. Although the first of Delta’s new jets won’t enter service until fall 2017, the airline is already searching for better ways to maintain and repair composite aircraft parts — which are very different from the metal parts it has been maintaining for years 

The airline is partnering with Georgia Tech to take a close look at current methods used to repair composite parts and identify ways to increase efficiency and bring down costs.

“Airlines want to create their own know-how on how to fix these structures because it’s cheaper and probably faster,” said Chuck Zhang, a professor in the Stewart School of Industrial and Systems Engineering. “But improved technologies are needed to help in the repair of composite parts. Much of it today is done by hand.”

Read the complete article in Research Horizons magazine

Until recently, that testing required the use of a real helicopter or costly display components that must be configured to operate in a laboratory environment. Thanks to an MFD/MPD emulator developed by the Georgia Tech Research Institute (GTRI) in collaboration with the Army Reprogramming Analysis Team (ARAT), the testing can now be done on ordinary laboratory computers anytime it is needed. The new emulator saves a significant amount of money and can help get software updates to deployed Army aviation forces faster.

“This is an exact replica of what’s on the helicopter, so when they’re testing the software upgrades in the laboratory, they see exactly what the pilot is going to see in the helicopter cockpit,” said William Miller, a GTRI principal research scientists who helped lead the project. “When the final software for the electronic warfare system is deployed to the field, it is already tested with the display. That saves money and time.”

The project began with two days of observation into the operation of a multi-function display in operational helicopters at Dobbins Air Reserve Base north of Atlanta and Redstone Arsenal in Alabama. GTRI engineers watched as the pilots put the Aviation Survivability Equipment (ASE) through all its operations and recorded what happened on video.

Next, a development team led by GTRI Research Scientist Heyward Adams began developing the emulator in a standard military Windows-based computer, using cards to simulate the sensors that would normally be providing data to the MFD. The emulator plugs into the aircraft’s 1553 bus, and can simulate inputs from two radar warning receivers: the AN/APR 39A(V)1/4 and AN/APR 48A .

Though the lab-based computer isn’t flight-worthy, it provides the exact look-and-feel of the Apache and Black Hawk EW systems so Army mission software developers can make sure the graphical elements are clear and correct.

“We ingest the data that’s coming out of the cards just like the real hardware would in the helicopter and represent it accurately,” Adams said. “The graphics we generate provide the exact look and feel, which we showed to pilots of the helicopter to make sure we were accurate.”

The emulator is already in use by Army mission software developers in the ARAT laboratories in Aberdeen Proving Ground, MD. The GTRI researchers say the system could be easily adapted to other aircraft.

“The framework we used to develop the emulator is scalable, so it’s not tied to just one specific multi-function display,” Adams said. “Our system is set up in such a way that we could quickly and cost-effectively emulate other systems, or even an entire cockpit.”

The ASE tracks threats such as surface-to-air missiles. Because the helicopters fly at low altitudes, there’s little time to react, and no time for errors. Most threats are handled automatically, but the crew needs to know what is happening at all times.

“For pilots flying these helicopters, this is a primary display for all the threat information they are encountering,” said Miller. “This is their lifeline, and pilots have to be confident that the system will work right every time.”

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The issue: Hobbyists can fly drones without FAA oversight as long as the aircraft weighs 55 pounds or less, flies in unpopulated areas, and remains within line of sight of the operator. Yet flying drones for commercial purposes requires review and approval by the FAA. The only way to get a thumbs-up from the FAA is to pursue airworthiness certification (an expensive and complicated process that can take up to a year), or secure a “Section 333 exemption.”

A Section 333 exemption allows the FAA to waive the airworthiness requirement as long as the commercial UAV flights are conducted under a number of restrictions. Among these restrictions: Drone operators must notify local aviation authorities two or three days prior to flight — and operations over people or near airports are off-limits.

“Securing a 333 exemption is doable for the movie industry since obtaining aerial footage can be planned far in advance,” observed Mike Heiges, a GTRI principal research engineer who leads the CNN project. “Yet journalists can’t operate under these rules for breaking news and chaotic situations where there may be emergency responders, police helicopters, or the National Guard.”

Granted, drones aren’t needed for every news story, but they provide a unique perspective in many situations, said Greg Agvent, senior director of news operations for CNN/US.

“Being able to fly over an area after an earthquake or tornado hits would provide a deeper understanding of how widespread the devastation is,” Agvent explained and pointed to the May 12 Amtrak train derailment in Philadelphia. “Part of the issue with the accident was the speed going into the curve. The ability to get footage from 200 feet in the air would have presented a better sense of the curve — context that you simply couldn’t get from the ground.”

Safety of news personnel is another benefit of drone journalism, Agvent added. “In many cases, such as a flood, safety would trump context. We could capture footage of an event without putting our people in harm’s way.”

Some of the research that comes out of the project will be helpful beyond newsgathering, observed Dave Price, a GTRI senior research technologist working on the project. “Commercial drones are of interest for crop monitoring and inspection of bridges and railroad tracks,” he explained. “Railroads and agriculture agencies will be able see the results of CNN’s camera selection and stabilization systems and take advantage of this for their own applications.”

The Right Stuff

During the past year, the researchers, including GTRI and CNN staff, have been investigating different UAVs that could carry the type of camera systems journalists need to shoot and transmit aerial footage.

That’s easier said than done. For one thing, the commercial drone industry is in its infancy. Manufacturers come and go, and there aren’t a great number with a long track record. Another challenge is finding the right equipment — airframes and payloads that match up. “It’s a trade-off,” Heiges explained. “You have to factor in size, weight, and power of what you want to put on the aircraft with what the aircraft can carry.”

Flight times for many commercial drones aren’t long enough for CNN’s purposes, nor is video quality high enough. “To install a better camera, you need a bigger vehicle for endurance,” Heiges said. “And that means stepping up to UAVs that were developed for the military, which dramatically increases price.”

GTRI has been testing drones since 2006 through the FAA’s certificate of authorization process, which enables public institutions to operate drones in national airspace for research purposes. Currently, GTRI holds 28 certificates of authorization for specific locations in five states. For the project with CNN, GTRI provides pilots to fly the drones in approved areas, plans the flight tests with CNN’s participation, collects data, and prepares reports with recommendations.

One of CNN’s takeaways from the flight tests: Drone journalism is no one-person show. “In most cases, especially for live video, you need three people,” Agvent said. This includes a pilot to guide the actions of the UAV and an operator for the camera, which is usually suspended under the drone and sits on gimbals for stabilization.

“The third person, a spotter, is particularly important in urban areas,” Agvent continued. “The spotter focuses solely on situational awareness and communicates to the pilot about people and other aircraft that may be in the area. In some cases, you could get by with a two- person team — a pilot/cameraman and a spotter — but a trio is best to ensure both high quality and safety.”

Advancing to Operational Protocols

“We’ve hit a lot of milestones in the past year,” Agvent said. “Now, we begin to work on the finer points of flight operations and coordinating with air traffic control.”

One of the FAA’s chief concerns with drones is getting the word out to manned aircraft about a UAV’s presence in the area. The current practice is to file a “notice to airmen” two or three days in advance.

A new technology known as automatic dependent surveillance-broadcast (ADS-B) could provide a just-in-time alternative to the notice to airmen. Developed by the FAA, this technology enables aircraft to broadcast their GPS coordinates to anyone in the local air space that has ADS-B, and vice-versa, so the drone operator would be able to see other aircraft.

“It’s like having an air traffic radar map inside your cockpit,” Heiges said. “Even better, unlike conventional radar, ADS-B works all the way to the ground.” That’s important, because, in some situations, journalists may need to cooperate with police helicopters or medical aircraft flying at low altitudes to pick up patients.

Geo-fencing technologies, which prevent UAVs from entering airport and other restricted areas, could add another layer of safety, Heiges added.

Because FAA rules prohibit drones from flying over people, crowd-control issues must also be resolved. For example, are journalists responsible for blocking off the area where they wish to fly drones — or do they communicate with on-scene commanders to find out where they can operate?

Over the next few months, GTRI and CNN will meet with regional emergency responders and other stakeholders to address these questions and develop an operational framework. Then GTRI will work with law enforcement agencies to test the procedures at remote locations. “We’ll hold mock trials and simulate circumstances that would happen in a breaking news situation,” Heiges explained.

Creating appropriate regulations for various types of UAV flights is important, as the flight landscape has changed dramatically in recent years.

“When people built radio-controlled airplanes out of balsa wood, they learned the rules for flying and flew aircraft at sanctioned sites,” Heiges said. “Yet in the past few years, we now have multi-rotors and quad-rotors with automatic stabilization that don’t require the same skills. People are flying them out of the box without knowing the rules. That can be dangerous if flown beyond visual range. Any significant accident will set back the industry, punishing those who do follow the rules.”

Even small drones could cause a helicopter or aircraft to go down if it gets caught in a propeller or pulled into an engine. Indeed, drones have been in the news this past summer for interfering with firefighting efforts in California, including a San Bernadino wildfire where drones operated by curious hobbyists caused fire pilots to pull out of the fray for 30 minutes, allowing the fire to spread.

“The one thing that doesn’t get talked about enough is the differentiation between hobbyists and commercial drone users — and that most of the problems are caused by laymen,” said Agvent. “Our goal is to create a framework that allows for safe integration of commercial drones for newsgathering. It’s about having trusted vendors, trusted aircraft, and trusted procedures in place to act in a safe manner.”

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Writer: T.J. Becker

A research team at the Georgia Institute of Technology has developed a novel technique that sets a new milestone for the strength and modulus of carbon fibers. This alternative approach is based on an innovative technique for spinning polyacrylonitrile (PAN), an organic polymer resin used to make carbon fibers.

The work is part of a four-year, $9.8 million project sponsored by the Defense Advanced Research Projects Agency (DARPA) to improve the strength of carbon-fiber materials. The research was reported recently in the journal Carbon.

"By using a gel-spinning technique to process polyacrylonitrile copolymer into carbon fibers, we have developed next-generation carbon fibers that exhibit a combination of strength and modulus not seen previously with the conventional solution-spun method," said Satish Kumar, a professor in the Georgia Tech School of Materials Science and Engineering who leads the project. “In addition, our work shows that the gel-spinning approach provides a pathway for even greater improvements.”

Kumar explained that tensile modulus – a measure of stiffness -- refers to the force needed to stretch a material by a given amount. Tensile strength expresses how much force is required to actually break the material.

In gel spinning, the solution is first converted to a gel; this technique binds polymer chains together and produces robust inter-chain forces that increase tensile strength. Gel spinning also increases directional orientation of fibers, which also augments strength. By contrast, in conventional solution spinning, a process developed more than 60 years ago, PAN co-polymer solution is directly converted to a solid fiber without the intermediate gel state and produces less-robust material.

The gel-spun carbon fiber produced by Kumar’s team was tested at 5.5 to 5.8 gigapascals (GPa) – a measure of ultimate tensile strength – and had a tensile modulus in the 354-375 GPa range. The material was produced on a continuous carbonization line at Georgia Tech that was constructed for this DARPA project.

“This is the highest combination of strength and modulus for any continuous fiber reported to-date,” Kumar said. “And at short gauge length, fiber tensile strength was measured as high as 12.1 GPa, which is the highest tensile-strength value ever reported for a PAN-based carbon fiber.”

Moreover, Kumar noted, the internal structure of these gel-spun carbon fibers measured at the nanoscale showed fewer imperfections than state-of-the-art commercial carbon fibers, such as IM7. Specifically, the gel-spun fibers display a lower degree of polymer-chain entanglements than those produced by solution spinning. This smaller number of entanglements results from the fact that gel spinning uses lower concentrations of polymer than solution-spinning methods.

Kumar and his team convert the gel-spun polymer mix into carbon fibers via a selective treatment process called pyrolysis, in which the spun polymer is gradually subjected to both heat and stretching. This technique eliminates large quantities of hydrogen, oxygen, and nitrogen from the polymer, leaving mostly strength-increasing carbon.

“It’s important to remember that the current performance of solution-spun PAN-based carbon fibers has been achieved after many years of material and process optimization – yet very limited material and process optimization studies have been carried out to date on the gel-spun PAN fiber,” Kumar said. “In the future, we believe that materials and process optimization, enhanced fiber circularity, and increased solution homogeneity will further increase the strength and modulus of the gel-spinning method.”

CITATION: Satish Kumar et al, “High strength and high modulus carbon fibers,” (Carbon, 2015). Carbon, 93, 81-87 (2015).  

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Writer: Rick Robinson

All STEP projects directly contribute to ongoing undergraduate- or graduate-level research work. This year, the program is conducted under the auspices of the Georgia Tech Aerospace Systems Design Laboratory (ASDL) and the NASA Georgia Space Grant Consortium (GSGC).

The two-month program is free to those who are accepted. The Atlanta-area students work in teams, advised by Georgia Tech research scientists and graduate students who serve as mentors.

“Interest in the program has been strong all spring, and applications have come in at a pretty high rate,” said Kelly Griendling, a Georgia Tech research engineer who designed and directed the STEP program. “I've gotten a lot of emails that basically say, ‘I heard from my friend that this was a great program, and I'd like to do it.’ ”

Last summer’s two-month program, she explained, dropped a wide range of knotty aerospace and vehicle related problems into the laps of student teams. The teams worked on portions of these real-world projects, and what the students achieved went to advance those projects. The students could ask for help from their mentors when necessary, but most of the time they worked on their own.

Kelly Ingle, a teacher at Kennesaw Mountain High School who is familiar with STEP, believes that the students who participated in last summer’s program experienced “real life,” gaining independence, improving problem-solving abilities, and learning to be team players in actual research.

“I have two students in my current classes who attended STEP last summer,” Ingle said. “Watching their approach to research this semester, it’s evident to me that the STEP experience was beneficial.”

The atmosphere in the STEP research laboratories last summer seemed both highly enthusiastic and very serious. On one late-July afternoon, a visitor to STEP found a 10th grade student working at a computer developing robotic-vision capability software for a U.S. Navy autonomous boat concept. A few feet away, two 10th grade students were using a CAD workstation to explore a NASA project that aims to move an asteroid millions of miles through space to a moon orbit.

Nearby, an 11th grader was trouble-shooting a hybrid-electric aircraft engine. At the next desk his colleagues were working on the hybrid engine itself, which had been designed to power an innovative unmanned aerial vehicle (UAV) that was being developed by yet another STEP team.

Last summer’s youthful researchers seemed to like STEP’s throw-them-in-the-deep-end approach.

Nick Tysver, a 10th grader from Lithia Springs High School who was on the autonomous boat/robotics vision team, told a visitor last summer: "It was really interesting – on the first day the mentors were like, 'This is your project, get going.’ That isn't at all like high school, where they inch you along – here they get you going in the right direction, and you know you're going to end up doing fine."

Projects for the 2015 STEP session haven’t been finalized. They will likely include both established and new research topics.

Both new students and some returning students will participate in this summer’s program.

“GSGC is thrilled to be working with ASDL to expand the highly effective program to multiple labs in Aerospace Engineering,” said Professor Stephen Ruffin, director of the GSGC.

Although summer 2015 applications have recently closed, interested parties can contact Kelly Griendling (kelly.griendling@asdl.gatech.edu) to inquire about applications for future semesters.

During the 2014 session, most students participated on one of six teams:

• The Hybrid Electric team worked on an airborne hybrid-electric propulsion system designed by a Georgia Tech graduate student.
• The UAV Design team was tasked with designing an unmanned aircraft that would be powered by the hybrid electric engine.
• The Asteroid Capture team worked on a NASA plan to redirect an asteroid to a stable orbit around the moon, where astronauts can later visit it for research purposes.
• The Quadrotor team was required to assemble and test several kits for quadrotors – small helicopters propelled by four propellers – and then design, build and test a custom quadrotor.
• The Rotor/Propeller Testing team performed a series of wind-tunnel tests on various motor-propeller combinations, to gather data and make performance predictions that can be used to support vehicle design efforts.
• The Autonomous Boat team focused on developing software code for an autonomous boat design, as part of a Naval Engineering Education Center (NEEC) project. 

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A team at the Georgia Tech Research Institute (GTRI) has designed a new approach that could lead to bathymetric lidars that are much smaller and more efficient than the current full-size systems. The new technology, developed under the Active Electro-Optical Intelligence, Surveillance and Reconnaissance (AEO-ISR) project, would let modest-sized unmanned aerial vehicles (UAVs) carry bathymetric lidars, lowering costs substantially. 

And, unlike currently available systems, AEO-ISR technology is designed to gather and transmit data in real time, allowing it to produce high-resolution 3-D undersea imagery with greater speed, accuracy, and usability.

These advanced capabilities could support a range of military uses such as anti-mine and anti-submarine intelligence and nautical charting, as well as civilian mapping tasks. In addition, GTRI’s new lidar could probe forested areas to detect objects under thick canopies.

"Lidar has completely revolutionized the way that ISR is done in the military – and also the way that precision mapping is done in the commercial world," said Grady Tuell, a principal research scientist who is leading the work. "GTRI has extensive experience in atmospheric lidar going back 30 years, and we're now bringing that knowledge to bear on a growing need for small, real-time bathymetric lidar systems."

Tuell and his team have developed a new GTRI lightweight lidar, a prototype that has successfully demonstrated AEO-ISR techniques in the laboratory. The team has also completed a design for a deployable mid-size bathymetric device that is less than half the size and weight of current systems and needs half the electric power.

Measuring Laser Light

To simulate the movement of an actual aircraft, the prototype must be "flown" over a laboratory pool. To do this, the researchers install the lidar onto a gantry above a large water tank in Georgia Tech’s Woodruff School of Mechanical Engineering and then operate it in a manner that simulates flight.

The lidar utilizes a high-power green laser that can penetrate water to considerable depths. Firing a laser beam every 10,000th of a second, the proxy aircraft allows the team to study the best methods for producing accurate images of objects on the floor of the pool.

The ultimate goal is to obtain accurate reflectance from the sea floor, but the presence of water makes that difficult. To capture good images, the GTRI lightweight lidar must make a series of adjustments that let it measure reflected laser beams as if there were no water present.

One challenge is that when a tightly focused light beam such as a laser hits water, it loses speed and bends, a familiar underwater effect called refraction. Due to changes in the water's surface, the angle of refraction varies constantly, and these changes in the refracted angle must be accounted for when computing the path of the light.

Another challenge is that the photons in the laser beam scatter in the water, like light from a car headlight hitting fog. The amount of this scattering depends on the water’s turbidity, which refers to the number of particles suspended in it. In addition, the water absorbs some of the light. 

Because of these two effects, a lidar system receives back only a tiny signal when its laser beam bounces off an underwater surface such as the sea floor. The signal-conditioning and sensor-processing capabilities of the lightweight lidar must be sophisticated enough to detect that small returning signal in an overall sea and air environment that is very noisy – meaning that it's filled with extraneous signals that interfere with the desired data.

Improving Critical Techniques

The ultimate product of a bathymetric lidar is a three-dimensional point cloud that describes the seafloor at high spatial resolution. Users of these data need to know the accuracy of each point.

GTRI’s researchers have devised a new approach for accuracy assessment called total propagated uncertainty (TPU). Using statistics, calculus, and linear algebra, the TPU technique propagates errors from the individual measurements – navigation, distance, and refraction angle – to estimate the accuracy of sea-floor measurements.

In a major milestone, the GTRI team was the first to demonstrate bathymetric lidar coordinate computation and TPU estimates in real time. To achieve the necessary processing speed, the team employs a mixed-mode computing environment composed of field programmable gate arrays (FPGAs), along with central-processing and graphics-processing units.

Each time a laser is fired, Tuell explained, it takes only a few nanoseconds for the beam to reach the bottom of the pool and bounce back. Once the beam returns, the lidar's high-speed computer digitizes the returned beam and computes ranges, coordinates, and TPU before the next shot of the laser. 

"In our laboratory tests, we're computing about 37 million points per second – which is exceptionally fast for a lidar system and gives us a great deal of information about the sea floor in a very short period of time," Tuell said. "The key is we're using FPGAs to do the necessary signal conditioning and signal processing, and we're doing it at exactly the time that we convert from an analog signal to a digital signal."

A Deployable Design

In addition to developing the proof-of-concept lidar prototype, the GTRI team has produced a CAD design for a deployable bathymetric device that is half the size and weight of current devices and has lower power needs. The immediate goal is to field such a mid-size device on a larger UAV such as an autonomous helicopter.

The longer-term aim is to use AEO-ISR technology to develop bathymetric lidars that could fly on small UAVs with payloads of 30 pounds or less. To help these lidars deliver maritime surveillance and mapping data in real time, most of the necessary signal processing would be done on the aircraft and only essential data would be transmitted to ground stations.

"We've provided a prototype that demonstrates the key technology, and we've completed a design for a mid-size design," Tuell said. "In the future, we believe small bathymetric lidars will perform military tasks, and also civilian tasks such as county-level mapping, with increased convenience and at greatly reduced cost."

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Writer: Rick Robinson

A new study of thermonuclear X-ray bursts on neutron stars reveals that, on very rare occasions, shells can be expelled at relativistic speeds - up to 30 percent of the speed of light. These velocities are the highest ever measured for a cosmic thermonuclear event, including novae and thermonuclear supernovae. This phenomenon, discovered in only 0.1 second worth of data in 40 years of space-based X-ray astronomy, sheds new light on how nuclear flames spread over surfaces of neutron stars. The study was published by authors at the Georgia Institute of Technnology, SRON Netherlands Institute for Space Research and Anton Pannekoek Institute of the University of Amsterdam.

In our galaxy, there are about 100 neutron stars that regularly burst in X-rays. When another star happens to be in the neighborhood of the neutron star, it may lose some of its hydrogen/helium  atmosphere to it. This material on the surface of the neutron star subsequently ignites a thermonuclear runaway reaction resulting in a minutes-long X-ray burst. The bursts are so luminous that they are easily visible from anywhere in the galaxy, provided an X-ray detector is used in space because X-rays cannot penetrate the Earth’s atmosphere.

X-ray bursts do not usually result in explosions. Gravity is so strong on the neutron star that any debris is firmly held tight to the surface. Only when a burst is powerful enough (in 20 percent of all cases), the pressure exerted by the radiation may be able to compensate for gravity. In such a case, the atmosphere is briefly lifted off the star and then pulled back again. The new study has now identified two bursts, out of more than 10,000 thus far detected, that are so powerful that a shell, visible for only a few tens of milliseconds, is flung loose from the star at 10 percent to 30 percent the speed of light.. 

Georgia Tech physics postdoctoral researcher Laurens Keek is a secondary author on the paper. He says the two explosions were powered by helium fusion.

“Helium burning produces a tiny amount of hydrogen,” he added. “This acts as a catalyst, and our computer simulations show that nuclear burning speeds up more than 100 thousand times. It takes detailed knowledge of nuclear reactions to explain how these X-ray bursts could set the speed record."

Record
"The found bulk velocities are a record for nuclear-powered phenomena," says SRON researcher, a primary author, Jean in 't Zand. "They are faster than the maxima measured in other stellar nuclear explosions (novae and type Ia supernovae). Presumably X-ray bursts provide us a window to the initial phase of thermonuclear runaways which is not available for (super)novae, since those are always discovered after that phase is over."

The exceptional outflows seen in these two bursts go hand in hand with very fast ignitions of the complete neutron star surface – within less than 1 millisecond. In 't Zand:  “This is very quick. It means that the nuclear flame spreads across the neutron star at velocities close to 0.1 times the speed of light. This puts interesting constraints on the theory of ignition and how the nuclear reaction chain works. Normal flame propagation mechanisms may not be viable in this regime. Instead, the neutron star atmosphere may be ignited in a so-called auto-ignition regime. In any case, this observational result is expected to stimulate new theoretical work."

Neutron stars
One can imagine a neutron star as a failed black hole. Both are remnants of stars at least a few times heavier than the sun, collapsed during a supernova after exhaustion of the nuclear fuel that kept them shining. Neutron stars are lighter than black holes, which makes them capable of making a full stop of the collapse just short of vanishing behind the event horizon, at a diameter of merely a few tens of kilometers. This implies that they have visible surfaces with unparalleled strong gravity, some 10,000 billion times stronger than on Earth. Throwing matter at it has a dramatic effect. That matter quickly piles up in a 1 m thick layer with such high pressures that a stellar sized H-bomb, powered by thermonuclear fusion, is ignited. The fusion lasts a fraction of a second and heats up the atmosphere to tens of millions of degrees. The subsequent cooling is visible as a minutes-long X-ray burst. The X-ray burst phenomenon was first discovered at SRON in 1975, with the first satellite built in the Netherlands (ANS). The measurements for the present study were carried out with NASA's Rossi X-ray Timing Explorer.

Publication
The research was performed by Jean in ’t Zand (SRON Netherlands Institute for Space Research), Laurens Keek (Center for Relativistic Astrophysics of the Georgia Institute for Technology, Atlanta) and Yuri Cavecchi (Anton Pannekoek Institute of the University of Amsterdam). The research results have been published in Astronomy & Astrophysics (volume 568, article A69, August 2014), see URL http://dx.doi.org/10.1051/0004-6361/201424044.

"For more than three decades, we have known that growing supermassive black holes at the centers of galaxies produce X-rays. Yet, how these X-rays are actually produced is still a mystery, said Ballantyne. "It seems the X-rays are generated in a 'corona' (analogous to the solar corona that can be seen during a solar eclipse), but figuring out even the basic details of these black hole coronae, such as its size, has been a major challenge. Now, NuSTAR, NASA's newest X-ray telescope, with its high sensitivity to a wide range of X-ray energies, is finally able to measure the details of black hole coronae. These measurements will allow astrophysicists to understand the engines that power some of the most energetic regions in the entire Universe."

Photo caption: The regions around supermassive black holes shine brightly in X-rays. Some of this radiation comes from a surrounding disk, and most comes from the corona, pictured here in this artist's concept as the white light at the base of a jet. This is one of a few possible shapes predicted for coronas. Image credit: NASA/JPL-Caltech

Literally.

As the principal investigator for the Prox-1 mission, Spencer anticipates the launch of a Georgia Tech-designed spacecraft (and an attached CubeSat) sometime within the next 18 months. Both components will be part of the multi-satellite payload launched by SpaceX Falcon Heavy rocket.

“Prox-1 will be the first spacecraft built by Georgia Tech to be launched into space,” said Spencer, who served as a mission designer for the Mars Pathfinder during nearly 2 decades with the Jet Propulsion Laboratory.

“We’ve built components before, but this is a Georgia Tech vehicle.”

Researched and tested by Spencer and his students in AE’s Space Systems Design Laboratory (SSDL),  the Prox-1 spacecraft was chosen for the launch by the Air Force Office of Scientific Research’s University Nanosatellite Program (UNP) during a system integration competition last year. The SSDL design trumped a field of 11 competitors.
 
Spencer will join Air Force officials at Kennedy Space Center when Prox-1 hitches a ride on the Falcon Heavy rocket sometime in 2016. And his team at Georgia Tech will be overseeing mission operations when Prox-1 is deployed and the LightSail is launched. But right now, everyone’s attention is focused on fine-tuning the satellites’ components while they are on the ground.

“Prox-1 is being built here on campus. We have everything except the propulsion units and the power distribution systems, so we’re testing other things, like structure, torque rods this summer. In the fall, it’ll look more like a spacecraft.”

That spacecraft will be small -- approximately 50cm x 50cm x 30cm – and will carry an even smaller micro-satellite (“CubeSat”) called the LightSail which will be launched from, and followed by, Prox-1. Once launched, the tiny nano-satellite will itself deploy a 32-square-meter solar energy-absorbing “sail” designed to power the vehicle during its flight.

Prox-1 will re-locate LightSail and determine its orbit using infrared imaging. It will then follow the satellite from a relatively short distance --100 to 150 meters. Spencer says successful demonstration of concept on this mission will greatly benefit future space travel.

“If we can accurately control one spacecraft’s trajectory relative to another, we can do on-orbit inspections of other spacecraft. This would be great when we launch Orion. We’ll be able to use CubeSats to inspect it for micro-meteor impacts,” he said.

“And the use of passive imaging is of great interest to the Air Force Research Lab. In the past, they’ve use LIDAR and RADAR, but this will really lower the cost if we can successfully demonstrate it.”

Find out more about Prox-1 in this video.

Prof. David Spencer's work on the $1.2 million Prox-1 project has been supported, in part, by a $220,000 grant from the Air Force Office of Scientific Research through the University Nanosat Program.

Department of Defense representatives were in attendance during a recent event where two of the low-power devices, which can change beam directions in a thousandth of a second, were demonstrated in an aircraft during flight tests held in Virginia during February 2014. One device, looking up, maintained a satellite data connection as the aircraft changed headings, banked and rolled, while the other antenna looked down to track electromagnetic emitters on the ground.

“We were able to sustain communication with the commercial satellite in flight as the aircraft changed headings dramatically,” explained Matthew Habib, a GTRI research engineer. “The antenna was changing beam directions to compensate for the aircraft headings. At the same time, we were maintaining communication with a device on the ground.”

In addition to rapidly altering its beam direction, the antenna’s frequency and polarization can also be changed by switching active components. The prototype used in this test operates from 500 to 3000 MHz with a plus or minus 60-degree hemispherical view. The latest prototypes have been able to provide gain to 6 GHz, opening more communication options to the end user. For the flight test, GTRI collaborated with SR Technologies, Inc. (SRT), a Florida company specializing in wireless engineering products.  SRT provides mobile communications hardware including L-Band mobile satellite, 802.11 (WiFi), and cellular solutions. 

For this effort, the A3 was matched with an SRT software defined radio focused on the L-Band mobile satellite frequency range. GTRI also collaborated with Aurora Flight Sciences to fly the antennas on their Centaur optionally piloted aircraft. 

Beyond its ability to be easily reconfigured, the low power consumption and flat form make the Agile Aperture Antenna ideal for aircraft such as UAVs that have small power supplies and limited surface area for integrating antennas.

“If you have a large ship or aircraft with lots of power, you can afford to use a phased-array or other type of steerable antenna,” noted Habib. “But when you are using small vehicles, especially robotic aircraft and self-sustaining vehicles that don’t include an operator, our antenna is a great solution.”

Composed of printed circuit boards, the antenna components weigh just two or three pounds.

“It’s not just about the low power and weight,” said James Strates, also a GTRI research engineer. “The simplicity of the system, the low fabrication cost and the ability to retrofit the A3 to an existing system also make it attractive to operators.”

Beyond use on aircraft, ships and ground vehicles, the antenna concept could also find application in mobile devices, where the dynamic tunability could help cut through congestion on cellular networks, noted Ryan Westafer, a GTRI research engineer.

“A small electronically tunable antenna could provide a lot of new opportunities for mobile devices,” he said.

As configured for the flight tests, the upward-looking A3 antenna had a beam 30 degrees wide that could be shifted up to 60 degrees in either direction to maintain contact with the satellite. For the downward-looking antenna, the beam was automatically adjusted to “stare” at a point on the ground, reducing the interference from nearby emitters, Westafer explained.

Because it doesn’t require mechanically moving a metal dish, the A3 can change beam direction 120 degrees in a thousandth of a second, which gives it a significant response time advantage over gimbaled antennas.

The A3’s weight and complexity are also much less than for a phased-array antenna with similar capabilities. The A3 antenna uses just one static feed point, while a phased-array must feed and control each element separately. Because of its low power consumption, the A3 requires no cooling system.

The Agile Aperture Antenna has also been tested on a Wave Glider autonomous ocean vehicle. Together with previous testing on a moving ground vehicle, the new evaluations demonstrate the operational flexibility of the antenna, Habib said. So far, the A3 has operated successfully at temperatures as low as 10 degrees below zero Fahrenheit, and as high as 100 degrees Fahrenheit.

To track the satellite, the antenna uses an inertial measurement unit to provide information about the aircraft’s pitch, roll and yaw – as well as its longitude, latitude and altitude. That information is sent to a controller that turns elements off and on to the change the beam direction to maintain communication. Before takeoff, the researchers had programmed into the device the location of the commercial satellite with which it was communicating.

The challenge ahead is to take advantage of the antenna’s unique capabilities – and to affect the way operators place antennas onto ground, air and sea vehicles.

“This is changing the way that we think about integrating antennas onto systems to provide new solutions,” Habib said. “Users have not had these capabilities before, and we are excited to see how our partners will be able to take full advantage of this antenna.”

Research News
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Media Relations Contacts: Lance Wallace (404-407-7280) (lance.wallace@gtri.gatech.edu) or John Toon (404-894-6986) (jtoon@gatech.edu).

Writer: John Toon

The epoch of reionization began about 200 million years after the Big Bang and astrophysicists agree that it took about 800 million more for the entire universe to become reionized. It marked the last major phase transition of gas in the universe, and it remains ionized today.

Astrophysicists aren’t in agreement when it comes to determining which type of galaxies played major roles in this epoch. Most have focused on large galaxies. However, a new theory by researchers at the Georgia Institute of Technology and the San Diego Supercomputer Center indicates scientists should also focus on the smallest.  The findings are reported in a paper published today in the journal Monthly Notices of the Royal Astronomical Society.

The researchers used computer simulations to demonstrate the faintest and smallest galaxies in the early universe were essential. These tiny galaxies – despite being 1000 times smaller in mass and 30 times smaller in size than the Milky Way – contributed nearly 30 percent of the UV light during this process.

Reionization experts often ignored these dwarf galaxies because they didn’t think they formed stars. It is assumed that UV light from nearby galaxies was too strong and suppressed these tiny neighbors.

“It turns out they did form stars, usually in one burst, around 500 million years after the Big Bang,” said John Wise, a Georgia Tech assistant professor in the School of Physics who led the study. “The galaxies were small, but so plentiful that they contributed a significant fraction of UV light in the reionization process.”

The team’s simulations modeled the flow of UV stellar light through the gas within galaxies as they formed. They found that the fraction of ionizing photons escaping into intergalactic space was 50 percent in small (more than 10 million solar masses) halos. It was only 5 percent in larger halos (300 million solar masses).  This elevated fraction, combined with their high abundance, is exactly the reason why the faintest galaxies play an integral role during reionization.

“It’s very hard for UV light to escape galaxies because of the dense gas that fills them,” said Wise. “In small galaxies, there’s less gas between stars, making it easier for UV light to escape because it isn’t absorbed as quickly. Plus, supernova explosions can open up channels more easily in these tiny galaxies in which UV light can escape.”

The team’s simulation results provide a gradual timeline that tracks the progress of reionization over hundreds of millions of years. About 300 million years after the Big Bang, the universe was 20 percent ionized. It was 50 percent at 550 million years. The universe was fully ionized at 860 million years after its creation.

“That such small galaxies could contribute so much to reionization is a real surprise,” said Michael Norman, distinguished professor of physics at UC San Diego and one of the co-authors of the paper. “Once again, the supercomputer is teaching us something new and unexpected; something that will need to be factored into future studies of reionization.”

The term reionized is used because the universe was ionized immediately after the fiery Big Bang. During that time, ordinary matter consisted of hydrogen atoms with positively charged protons stripped of their negatively charged electrons. Eventually, the universe cooled enough for electrons and protons to combine and form neutral hydrogen. They didn’t give off any optical or UV light. Without the light, astrophysicists aren’t able to see traces of how the cosmos evolved during these Dark Ages using conventional telescopes. The light returned when reionization began, allowing experts like Wise to pinpoint the youngest galaxies and study their features.

The research team expects to learn more about these faint galaxies when the next generation of telescopes is operational. For example, NASA’s James Webb Space Telescope, scheduled to launch in 2018, will be able to see them.

This research was supported by the National Science Foundation (NSF) (AST 1211626, AST 1333360 and AST 1109243). Any conclusions expressed are those of the principal investigator and may not necessarily represent the official views of the NSF.

AEgis Technologies, specialists in modeling and simulation, contracted GTRI’s Applied Systems Laboratory to collaborate with MDA on testing high-altitude air defense missiles. ASL is in its second phase of a multi-year project utilizing “hardware-in-the-loop” testing to enable more accurate modeling and simulation for its customer. 

“Testing a missile can be very expensive,” said GTRI Senior Research Engineer and principal investigator Glenn Parker. “Additionally, because of the large number of control variables in a real exercise, it isn’t technically feasible to get complete testing coverage. High-fidelity simulation addresses many of these concerns, but even with modern processors it can take days to compute the trajectory and heat signature of a complex ballistic target.”

Hardware-in-the-loop simulations use portions of the real missile hardware, such as the seeker, with any missing pieces made up by simulated components.

“We use the missile’s actual guidance system and manipulate simulated inputs to make the hardware think it is flying,” Parker said. “By using real hardware in tests, confidence in the results is much higher than in fully simulated models. For non-reusable portions of the missile like the motor and warhead, the use of simulation models makes it possible to run thousands of test cycles without leaving the laboratory, and for less than the cost of one live test.”

With current testing models, thermal signature databases must be computed offline prior to the test, and can take up to three days for a mere fifteen minutes of simulation time. Any alteration to the parameters—altitude, weather, terrain, or even the position of the sun—requires a total re-coding of the database. Testing a missile launch from Hawaii, for example, to intercept a target at a certain distance, altitude and speed takes a long time to calculate all of the missile hardware inputs that are used in the test.

What GTRI is working on, according to Parker, will enable the simulated components to be “looped in” for real-time calculation, eliminating the need for database computation ahead of time. Using off-the-shelf NVIDIA graphics cards, the group will work to provide the seeker with simulated thermally emissive ballistic targets heated by atmospheric effects in real time. The team will be using CUDA, NVIDIA’s parallel computing architecture.

“Our goal is to calculate and provide inputs at up to 200 Hz, which means simulated measurements are sent to the seeker unit 200 times each second,” Parker said. “This will allow us to run dozens of tests in the amount of time we used to spend calculating data for a single run. Test parameters can be changed on the fly—MDA will be able to run many more ‘what if’ scenarios before fielding a defense system.”

AEgis Technologies in Huntsville is the prime contractor of the project. They will operate the Army-owned, hardware-in-the-loop test bed and generate scenarios for use in simulations.

GTRI provides the expertise in real-time computing. Prior to this, AEgis had worked indirectly with GTRI’s Electro-Optical Systems Laboratory (EOSL) on the same program, which supported ultraviolet sensor testing.

“We selected GTRI based on what I knew of EOSL’s capabilities, and their expertise in GPU technology,” said AEgis Program Manager Dennis Bunfield. “GTRI’s CUDA expertise is a great value, and their expertise in verification and validation is invaluable.”

The system will be scalable, and the plan is to take what they learn from this project and use it elsewhere in the defense industry. The thermal solver aspect of the project, for example, will be useful for any simulation requiring a real-time solution for thermal image simulation.

“I think with some enhancements to the code framework, the capabilities can be extended to generate signatures in other regions, such as UV, the visible spectrum and for LADAR,” Bunfield said. “Aside from military applications, it could be possible to use the thermal solver to commercial and manufacturing applications, such as thermal analysis simulation.”

“We’re working with AEgis Technologies to best model and simulate firing and the performance of these missiles by providing scenario inputs at the true hardware rate,” Parker said. “Our main goal—writing a massively parallel NVIDIA CUDA thermal differential equation solver—will enable faster and more effective testing of high-cost components at hardware-in-the-loop testing centers.”

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Media Relations Contacts: Lance Wallace (lance.wallace@gtri.gatech.edu) (404-407-7280) or John Toon (jtoon@gatech.edu) (404-894-6986).

Writer: Robert Nesmith

New research at the Georgia Institute of Technology indicates that ultraviolet photons emitted by the sun likely cause H₂O molecules to either quickly desorb or break apart. The fragments of water may remain on the lunar surface, but the presence of useful amounts of water on the sunward side is not likely.

“Overall, the Moon will lose water efficiently when the solar photons are hitting it,” said Thomas Orlando, the Georgia Tech professor who led the study. “The water also desorbs thermally. When they photodesorb or thermally desorb, the velocities are too low for the water to escape so it will bounce around until it gets trapped in the permanently shadowed regions and the poles or break apart in transit.”

The Georgia Tech team built an ultra-high vacuum system that simulates conditions in space, then performed the first-ever reported measurement of the water photodesorption cross section from an actual lunar sample. The machine zapped a small piece of the moon with ultraviolet (157 nm) photons to create excited states and watched what happened to the water molecules. They either came off with a cross section of ~ 6 x 10⁻¹⁹ cm²  or broke apart with a cross section of  ~ 5  x 10⁻¹⁹ cm^2.. According to the team’s measurements, approximately one in every 1,000 molecules leave the lunar surface simply due to absorption of UV light.

Georgia Tech’s cross section values can now be used by scientists attempting to find water throughout the solar system and beyond.

“The cross section is an important number planetary scientists, astrochemists and the astrophysics community need for models regarding the fate of water on comets, moons, asteroids, other airless bodies and interstellar grains,” said Orlando, professor in the School of Chemistry and Biochemistry. 

The number is relatively large, which establishes that solar UV photons are likely removing water from the moon’s surface. This research, which was carried out primarily by former Georgia Tech Ph.D. student Alice DeSimone, indicates the cross sections increase even more with decreasing water coverage. That’s why it’s not likely that water remains intact as H₂O on the sunny side of the moon. Orlando compares it to sitting outside on a summer day.

“If a lot of sunlight is hitting me, the probability of me getting sunburned is pretty high,” said Orlando, a professor in the School of Chemistry and Biochemistry and School of Physics. “It’s similar on the moon. There’s a fixed solar flux of energetic photons that hit the sunlit surface, and there’s a pretty good probability they remove water or damage the molecules.“

The result, according to Orlando, is the release of molecules such as H₂O, H₂ and OH as well as the atomic fragments H and O.  

 The research is published in two companion articles in the Journal of Geophysical Research: Planets. The first discusses the water photodesorption. The second paper details the photodissociation of water and the  O(³P_J) formation on a lunar impact melt breccia. 

Orlando is the associate director of Georgia Tech’s Center for Space Technology and Research (C-STAR). C-STAR is an interdisciplinary research center that serves to organize, integrate and facilitate the impact of Georgia Tech's space science and space technology research activities. The center brings together a wide range of Georgia Tech faculty, active in space science and space technology research, and functions as the Institute’s focal point for growth of the space industry in the state of Georgia.

This material is based upon work supported by NASA under award number NNX11AP13G. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NASA.

In a universe with tens of billions of galaxies, how would we see it? What would such a beacon look like? And how would we distinguish it from other bright, monumental intergalactic events, such as supernovas?

"Black holes by themselves do not emit light," said Tamara Bogdanovic, an assistant professor of physics at the Georgia Institute of Technology. "Our best chance to discover them in distant galaxies is if they interact with the stars and gas that are around them."

In recent decades, with improved telescopes and observational techniques designed to repeatedly survey the vast numbers of galaxies in the sky, scientists noticed that some galaxies that previously looked inactive would suddenly light up at their very center.

"This flare of light was found to have a characteristic behavior as a function of time. It starts very bright and its luminosity then decreases in time in a particular way," she explained. "Astronomers have identified those as galaxies where a central black hole just disrupted and 'ate' a star. It's like a black hole putting up a sign that says 'Here I am.'"

Using a mix of theoretical and computer-based approaches, Bogdanovic tries to predict the dynamics of events such as the black-hole-devouring-star scenario described above, also known as a "tidal disruption." Such events would have a distinct signature to someone analyzing data from a ground-based or space-based observatory.

Using National Science Foundation-funded supercomputers at the Texas Advanced Computing Center (Stampede) and the National Institute for Computational Sciences (Kraken), Bogdanovic and her collaborators recently simulated the dynamics of these super powerful forces and charted their behavior using numerical models.

Tidal disruptions are relatively rare cosmic occurrences. Astrophysicists have calculated that a Milky Way-like galaxy stages the disruption of a star only once in about 10,000 years. The luminous flare of light, on the other hand, can fade away in only a few years. Because it is such a challenge to pinpoint tidal disruptions in the sky, astronomical surveys that monitor vast numbers of galaxies simultaneously are crucial.

Huge difference

So far, only a few dozen of these characteristic flare signatures have been observed and deemed "candidates" for tidal disruptions. But with data from PanSTARRS, Galex, the Palomar Transient Factory and other upcoming astronomical surveys becoming available to scientists, Bogdanovic believes this situation will change dramatically.

"As opposed to a few dozen that have been found over the past 10 years, now imagine hundreds per year--that's a huge difference!" she said. "It means that we will be able to build a varied sample of stars of different types being disrupted by supermassive black holes."

With hundreds of such events to explore, astrophysicists' understanding of black holes and the stars around them would advance by leaps and bounds, helping determine some key aspects of galactic physics.

"A diversity in the type of disrupted stars tells us something about the makeup of the star clusters in the centers of galaxies," Bodganovic said. "It may give us an idea about how many main sequence stars, how many red giants, or white dwarf stars are there on average."

Tidal disruptions also tell us something about the population and properties of supermassive black holes that are doing the disrupting.

"We use these observations as a window of opportunity to learn important things about the black holes and their host galaxies," she continued. "Once the tidal disruption flare dims below some threshold luminosity that can be seen in observations, the window closes for that particular galaxy."

Role of supercomputer

In a recent paper submitted to the Astrophysical Journal, Bogdanovic, working with Roseanne Cheng (Center for Relativistic Astrophysics at Georgia Tech) and Pau Amaro-Seoane (Albert Einstein Institute in Potsdam, Germany), considered the tidal disruption of a red giant star by a supermassive black hole using computer modeling.

The paper comes on the heels of the discovery of a tidal disruption event in which a black hole disrupted a helium-rich stellar core, thought to be a remnant of a red giant star, named PS1-10jh, 2.7 billion light years from Earth.

The sequence of events they described aims to explain some unusual aspects of the observational signatures associated with this event, such as the absence of the hydrogen emission lines from the spectrum of PS1-10jh.

As a follow-up to this theoretical study, the team has been running simulations on Kraken and Stampede, as well as the Georgia Tech's high performance computing clusters. The simulations reconstruct the chain of events by which a stellar core, similar to the remnant of a tidally disrupted red giant star, might evolve under the gravitational tides of a massive black hole.

"Calculating the messy interplay between hydrodynamics and gravity is feasible on a human timescale only with a supercomputer," Cheng said. "Because we have control over this virtual experiment and can repeat it, fast forward, or rewind as needed, we can examine the tidal disruption process from many perspectives. This in turn allows us to determine and quantify the most important physical processes at play."

The research shows how supercomputer simulations complement and constrain theory and observation.

"There are many situations in astrophysics where we cannot get insight into a sequence of events that played out without simulations. We cannot stand next to the black hole and look at how it accretes gas. So we use simulations to learn about these distant and extreme environments," Bogdanovic said.

One of Bogdanovic's goals is to use the knowledge gained from simulations to decode the signatures of observed tidal disruption events.

"The most recent data on tidal disruption events is already outpacing theoretical understanding and calling for the development of a new generation of models," she explained. "The new, better quality data indicates that there is a great diversity among the tidal disruption candidates. This is contrary to our perception, based on earlier epochs of observation, that they are a relatively uniform class of events. We have yet to understand what causes these differences in observational appearance, and computer simulations are guaranteed to be an important part of this journey."

-- Written by Aaron Dubrow of the National Science Foundation.

“These competitively awarded research grants build on the strengths of both JPL and Georgia Tech,” said Georgia Tech Professor and C-STAR Director Robert Braun. “They are designed to foster future research collaborations between these two institutions, and are well aligned with our nation’s future needs in space science and space technology.”

The four faculty members and their projects are:

• Brian Gunter (Assistant Professor, Guggenheim School of Aerospace Engineering)

Utilizing nano-satellite technology for improved monitoring of Earth’s time-variable gravity

• David Spencer (Professor of the Practice, Guggenheim School of Aerospace Engineering)

Developing Mars technology demonstration missions in lower Earth orbit and deep space micro-spacecraft

• Panagiotis Tsiotras (Professor, Guggenheim School of Aerospace Engineering)

Autonomous energy-projecting systems for robotic exploration of extreme environments

• James Wray (Assistant Professor, School of Earth and Atmospheric Sciences)
  Icy satellite surface compositions from infrared spectroscopy
  
  

Each faculty member will partner with relevant JPL researchers during the summer.

"The C-STAR summer faculty program provides an excellent opportunity to connect leading Georgia Tech faculty with researchers at JPL,” said JPL Chief Scientist Daniel McCleese. “The exciting projects chosen this year will open up new collaborations, and enhance both JPL and Georgia Tech's space science efforts.”

JPL will also fund a summer experience for Woodruff School of Mechanical Engineering graduate student Peter Ngo to study low-cost, higher-risk flight projects.

C-STAR is an interdisciplinary research center that serves to organize, integrate and facilitate the impact of Georgia Tech's space science and space technology research activities. C-STAR brings together a wide range of Georgia Tech faculty, active in space science and space technology research, and functions as the Georgia Tech focal point for growth of the space industry in the state of Georgia. Braun serves as the director.  Professor Thomas Orlando is the associate director.

In 2012, Georgia Tech and JPL, a division of Caltech, formally entered into a strategic partnership designed to promote and encourage collaboration between the institutions, with a focus on research collaborations and personnel exchanges in science and engineering fields of mutual interest. C-STAR serves as the Georgia Tech focal point for this newly established partnership with JPL.
Written by Meghan Feeney, Institute Communications Student Assistant

Scientists believe Europa is one of the planetary bodies in our solar system most likely to have conditions that could sustain life, an idea reinforced by magnetometer readings from the Galileo spacecraft detecting signs of a salty, global ocean below the moon’s icy shell.

Without direct measurements of the ocean, scientists have to rely on magnetometer data and observations of the moon’s icy surface to account for oceanic conditions below the ice.

Regions of disrupted ice on the surface, known as chaos terrains, are one of Europa’s most prominent features. As lead author Krista Soderlund and colleagues explain in this week’s online edition of the journal Nature Geosciences, the chaos terrains, which are concentrated in Europa’s equatorial region, could result from convection in Europa's ice shell, accelerated by heat from the ocean. The heat transfer and possible marine ice formation may be helping form diapirs, or warm compositionally buoyant plumes of ice that rise through the shell.

In a numerical model of Europa’s ocean circulation, the researchers found that warm rising ocean currents near the equator and subsiding currents in latitudes closer to the poles could account for the location of chaos terrains and other features of Europa’s surface. Such a pattern coupled with regionally more vigorous turbulence intensifies heat transfer near the equator, which could help initiate upwelling ice pulses that create features such as the chaos terrains.

“The processes we are modeling on Europa remind us of processes on Earth,” says Soderlund. A similar process has been observed in the patterns creating marine ice in parts of Antarctica.

The current patterns modeled for Europa contrast with the patterns observed on Jupiter and Saturn, where bands of storms form because of the way their atmospheres rotate. The physics of Europa’s ocean appear to have more in common with the oceans of the “ice giants” Uranus and Neptune, which show signs of three-dimensional convection.

“This tells us foundational aspects of ocean physics,” notes co-author Britney Schmidt, assistant professor at the Georgia Institute of Technology. More importantly, adds Schmidt, if the study’s hypothesis is correct, it shows that Europa’s oceans are very important as a controlling influence on the surface ice shell, offering proof of the concept that ice-ocean interactions are important to Europa.

“That means more evidence that the ocean is there, that it’s active, and there are interesting interactions between the ocean and ice shell,” says Schmidt, “all of which makes us think about the possibility of life on Europa.”

Soderlund, who has studied icy satellites throughout her science career, looks forward to the chance to test her hypothesis through future missions to the Jovian system. The European Space Agency’s JUICE mission (JUpiter ICy moons Explorer) will give a tantalizing glimpse into the characteristics of the ocean and ice shell through two flyby observations. NASA’s Europa Clipper mission concept, under study, would complement the view with global measurements.

Soderlund says she appreciates the chance “to make a prediction about Europa’s subsurface currents that we might know the answer to in our lifetimes — that’s pretty exciting.”

Research funding was provided by the Institute for Geophysics, part of the University of Texas at Austin’s Jackson School of Geosciences.
Written by J.B. Bird, Jackson School of Geosciences, the University of Texas at Austin

Researchers at the Georgia Tech Research Institute (GTRI) produced the arrays using unique technology that grows bundles of vertically-aligned nanotubes embedded in silicon chips. In future versions of electrically-powered ion thrusters, electrons emitted from the carbon nanotube tips may be used to ionize a gaseous propellant such as xenon. The ionized gas would then be ejected through a nozzle to provide thrust for moving a satellite in space.

“The mission will characterize how well these field emission electron sources operate in the space environment relative to how well they work on the ground in vacuum chamber,” said Jud Ready, a GTRI principal research engineer. “Launch vibrations and exposure to a space environment that includes atomic oxygen and micrometeorites could have some unusual effects on the arrays. This mission will help us evaluate whether these carbon nanotube electron emitters could be used in ion thrusters.”

Existing ion thrusters rely on thermionic cathodes, which use high temperatures generated by electrical current to produce electrons. These devices require significant amounts of electricity to generate the heat, and must consume a portion of the propellant for their operation.
If the carbon nanotube arrays can be used as electron emitters, they would operate at lower temperatures with less power – and without using the limited on-board propellant. That could allow longer mission times for satellites, or reduce the weight of the micro-propulsion systems.

The carbon nanotube arrays are part of ALICE, a CubeSat micro-satellite developed and built by the Air Force Institute of Technology at Wright-Patterson Air Force Base in Ohio. On a mission scheduled for Dec. 5 from Vandenberg Air Force Base in California, ALICE will ride into space on an Atlas V rocket being used to launch a separate and much larger payload. Just 10 by 10 by 30 centimeters in size, ALICE will be part of an array of eight CubeSats – so named because they fit into small modular launchers attached to the main satellite.

The work could lead to improved micro-propulsion systems useful to small spacecraft, said Jonathan Black, director of the Center for Space Research and Assurance at AFIT.

“Technology like the devices being tested on ALICE is essential to our future ability to maneuver micro satellites or change their orbits,” he explained. “Being able to incorporate propulsion into microsatellites like CubeSats increases mission longevity and the types of missions they can perform. Successful demonstrations of advanced technologies like those being flown on ALICE will ultimately lead to smaller, lighter and more energy-efficient propulsion, resulting in decreased launch costs while increasing the performance of all satellites using electric propulsion.”

Utilizing a multi-departmental team, AFIT engineers in the Electrical Engineering Department developed a payload to directly expose the carbon nanotube arrays to the space environment while protecting an identical control array within the satellite. The arrays, which are approximately one centimeter square, will be switched on and off and their behavior studied. The payload experiment utilizes a sensor device known as the Integrated Miniaturized Electromagnetic Analyzer (iMESA), designed by engineers at the U.S. Air Force Academy (USAFA). The data collected from the satellite will be downloaded and processed at AFIT by students and technicians in the Department of Aeronautics and Astronautics.

The carbon nanotube arrays are excellent conductors and their geometry makes them ideal electron emitters.

“We use carbon nanotubes because they have a high aspect ratio and provide a nanoscale point that emits the electrons,” said Graham Sanborn, who worked on the project as part of his Ph.D. thesis in Georgia Tech’s School of Materials Science and Engineering. “The electric field focuses on the tip so we are able to get electron emission at lower voltages than might be required for other materials.”

GTRI uses a series of deposition and etching steps to fabricate the arrays in clean rooms at Georgia Tech. Each one-centimeter square array contains as many as 50,000 nanotube bundles, and each bundle is grown from a five-micron pit etched into the silicon.

“The design has specific geometry to prevent electrical shorting between electrodes that are very close together,” explained Sanborn.

Spacecraft are launched using chemical rockets that provide large amounts of thrust. Once in orbit, however, the vehicles can use electrically-powered thrusters to change orbits or make other maneuvers.

“Ion thrusters provide very low amounts of thrust,” Sanborn said. “They are just pushing out gas molecules, but they operate very efficiently. Ion thrusters can operate for thousands of hours at a time. Cumulatively, you can achieve a significant velocity change.”

The ALICE acronym is composed of several other acronyms. The “A” represents AFIT, while the “L” is for LEO – the low Earth orbit where the satellite will operate. The “I” represents the iMESA system; the “C” is for the carbon nanotubes, while the “E” represents “Experiment.”

The satellite, the first for AFIT, was designed, tested and integrated by a multi-departmental team of professors, students and technicians. The partnership with GTRI and USAFA provided students in each institution an opportunity to participate in ground-breaking research with the potential to impact numerous future satellites employing electric propulsion.

Other potential applications for Georgia Tech’s CNT-based electron emitters include displays, electrodynamic tethers, vacuum electronics and traveling wave tubes.

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Media Relations Contacts: John Toon (404-894-6986)(jtoon@gatech.edu) or Lance Wallace (404-407-7280)(lance.wallace@gtri.gatech.edu).

Writer: John Toon

The work is part of the U.S. Navy's Future Airborne Capability Environment (FACE™) project. The Navy’s FACE team is working with the FACE consortium, a government, industry and academia consortium managed by The Open Group®, to develop a new technical standard that governs how avionics software communicates with other avionics software and hardware components – to control aircraft sensors, effectors and other mission critical systems to deliver warfighting capability. 

Georgia Tech’s support of the FACE project is funded by the Naval Air Systems Command (NAVAIR) Air Combat Electronics Program Office (PMA-209) and the U.S. Army Aviation and Missile Research Development and Engineering Center (AMRDEC). Georgia Tech's work principally involves validating and maturing the FACE Technical Standard by producing reference software built according to the new FACE standards. 

"The FACE standard lets us streamline software production and software upgrades, which are vital for keeping U.S. pilots safe and delivering our military capabilities," said Douglas Woods, a research scientist leading the work at the Georgia Tech Research Institute (GTRI), Georgia Tech’s applied research arm. "In tackling this important work, we created a one-Georgia Tech team, uniting expertise from both GTRI and the School of Electrical and Computer Engineering.

“Basically, the FACE standard dictates how everything should fit together,” Woods said. “The FACE Technical Standard lets developers connect software and hardware in a uniform way, so that one software application can work with a variety of different hardware.”

The digital control portion of an avionics system is similar in some ways to the familiar personal computer, explained Woods, who is working on the FACE project with professor George Riley of the School of Electrical and Computer Engineering. That's because both computers and avionics use application software that runs on processing hardware; the application software communicates with the hardware via intermediary software known as an operating system.

Unlike a PC, however, the application software and operating system of an avionics system are very compact and robust for safety, security and performance reasons. 

For decades, these embedded applications have been uniquely designed to work with the specific operating system and hardware components contained in a given avionics system. Thus, the application software embedded in an avionics device worked with that device only, requiring significant rework or redundant development when similar capability is needed on new hardware or different hardware from another source.

This specialized software has also resulted in software modification having to be performed by the company or companies that created the software/hardware combination in the first place, reducing the opportunity for future competition.

That's where the FACE concept comes in. The FACE architecture specifies that designers use application programming interfaces (APIs) that are essentially a standardized software layer that translates between the application on one level and the other software applications, the operating system and hardware at other levels. The result is that designers can readily modify application software, integrate it back into the system, and expect it to work.  

"As long as you adhere to the standard software interfaces specified in the FACE Technical Standard, then changing the embedded application software to add capability to the system becomes straightforward," Woods said. "Any competent software engineer should be able to write an application that can talk to those interfaces, and that makes it possible to add in new capabilities quickly and easily."

Georgia Tech expects to be involved in tests that will demonstrate to the Navy the portability of capabilities using the FACE Technical Standard, he added.

The FACE Technical Standard takes advantage of the Portable Operating System Interface (POSIX), a group of open software standards aimed at making applications compatible with various operating systems. POSIX uses a uniform application programming interface (API), command line shells and utility interfaces that promote software compatibility among Unix, Linux and other Unix-like operating systems.

Georgia Tech has been working with the Navy FACE team for more than two years on the development of software code that provides an interface built to the FACE standard. Vanderbilt University, which is also involved in the effort, is creating a software developers' toolkit and conformance tools to be used with the FACE Technical Standard. 

"Our Georgia Tech/GTRI team has been successful in producing a FACE infrastructure prototype that is POSIX conformant and adheres fully to the standards developed by the FACE consortium," Riley said. "From a technical standpoint, this software can do the job that was assigned, which is to allow applications that conform to the FACE APIs to be interchangeable."

A contract that requires use of the FACE Technical Standard, Edition 1.0, in the Navy's C-130T aircraft has already been awarded, Woods said. The FACE Technical Standard, Edition 2.0, was recently released, and the FACE consortium is currently developing Edition 3.0 of the standard. 

The Navy's FACE team has been recognized with several awards, including two Naval Air Warfare Center, Aircraft Division (NAWCAD) Commander’s Awards, a NAWCAD Innovation Award, and the Defense Standardization Program Achievement Award.

"The FACE initiative represents a major step forward in rapidly integrating new capabilities for a variety of airborne defense systems," said Capt. Tracy Barkhimer, program manager for PMA-209. "The FACE initiative has benefited greatly from NAVAIR's partnership with Georgia Tech and Vanderbilt. They have brought a wealth of knowledge and experience that has been vital to the validation and rapid maturation of the FACE Technical Standard." 

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Writer: Rick Robinson

"Developing new sensor technologies that can be effectively employed from the air is a priority today given the rapidly increasing use of unmanned aircraft," said Michael Brinkmann, a GTRI principal research engineer who is leading the work. "Given suitable technology, small UAVs can perform complex, low-altitude missions effectively and at lower cost. The GAUSS system gives GTRI and its customers the ability to develop and test new airborne payloads in a rapid, cost effective way."

The current project includes development, installation and testing of a sensor suite relevant to many of GTRI’s customers. This suite consists of a camera package, a signals intelligence package for detecting and locating ground-based emitters, and a multi-channel ground-mapping radar.

The radar is being designed using phased-array antenna technology that enables electronic scanning. This approach is more flexible and agile than traditional mechanically steered antennas.

The combined sensor package is lightweight enough to be carried by the GAUSS UAV, which is a variant of the Griffon Outlaw ER aircraft and has a 13.6-foot wingspan and a payload capacity of approximately 40 pounds.     

The aircraft navigates using a high precision global positioning system (GPS) combined with an inertial navigation system. These help guide the UAV, which can be programmed for autonomous flight or piloted manually from the ground. The airborne mission package also includes multi-terabyte onboard data recording and a stabilized gimbal that isolates the camera from aircraft movement. 

Heavier sensor designs have several disadvantages, observed Mike Heiges, a principal research engineer who leads the GTRI team that is responsible for flying and maintaining the UAV platform. Larger sensors require larger unmanned aircraft to carry them, and those aircraft use bigger engines and must fly higher to avoid detection.

"Rather than have your design spiral upwards until you're using very large and expensive aircraft, smaller sensors allow the use of smaller aircraft," Heiges said.  "A smaller UAV saves money and is logistically easier to support. But most important, it can gather information closer to the tactical level on the ground, where it's arguably most valuable."

The GTRI team has developed a modular design that allows the GAUSS platform to be reconfigured for a number of sensor types. Among the possibilities for evaluation are devices that utilize light detection and ranging (LIDAR) technology and chemical-biological sensing technology.

"The overall concept for the GAUSS program is that the airplane itself will be simply a conveyance, and we can mount on it whatever sensor/communication package is required," said Brinkmann.

The radar package that GTRI is currently installing and testing is complex, he explained.  In addition to phased-array scanning capability, the radar operates in the X-band, is capable of five acquisition modes and can be programmed to transmit arbitrary waveforms.

"This radar is a very flexible system that will be able to do ground mapping, as well as detecting and tracking objects moving around on the ground," Brinkmann said. "These multiple sensing capabilities offer many possibilities for defense operations, along with search-and-rescue and disaster-recovery operations.”  

Possible applications include using the signals intelligence package to locate people buried in rubble by searching for cell phone signals, he said. In another scenario, a group of self-guided UAVs could be used to create an ad hoc cell phone network. That application could be potentially valuable in a post-disaster scenario where existing cell phone towers have been disabled, as happened after Hurricane Katrina, the Haiti earthquake and other events.

"The GAUSS platform is extremely helpful for proof-of-principle development and testing new concepts for airborne sensors," Brinkmann said. "It gives GTRI a convenient and flexible base from which to pursue significant research in a variety of disciplines."

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Writer: Rick Robinson

Known as an analog beam-former, the GTRI device is part of the radiometer, which is being tested by NASA on a Global Hawk unmanned aerial vehicle. The radiometer measures microwave radiation emitted by the sea foam that is produced when high winds blow across ocean waves. By measuring the electromagnetic radiation, scientists can remotely assess surface wind speeds at multiple locations within the hurricanes.

HIRAD could provide detailed information about the wind speeds and rain intensity inside hurricanes without the need to fly manned aircraft through the storms. In addition to the beam-former design, GTRI researchers also provided assistance to NASA with improvements aimed at a potential future, more advanced version of the radiometer.

“Improved knowledge of the wind speed field will enable the National Hurricane Center to better characterize the storm’s intensity,” explained Timothy Miller, Research and Analysis Team Lead for the Earth Science Office at the NASA Marshall Space Flight Center. “Better forecasts of storm intensity and structure will enable better warnings of such important factors as wind strength and storm surge. That would allow businesses and residents to prepare with more confidence in their knowledge of what is coming.”

HIRAD was flown above two hurricanes in 2010 and a Pacific frontal system in 2012. Data it gathered on wind and rain will be provided to the scientific community for use in numerical modeling, and could also guide development of a next-generation system that would provide information on wind direction in addition to measuring wind speed and rain intensity.

“We have verified the instrument concept in terms of sensitivity to wind speed and rain rate,” Miller said. “We have also learned a lot about the factors that need to be considered in developing calibrated images from the flight data. That work is still ongoing.”

GTRI researchers supported development of the radiometer with design of the beam-formers, which are part of the radiometer’s array antenna. The array antenna gathers microwave signals from the ocean and the GTRI-designed devices – several of which are required – form “fan” beams of electromagnetic energy across the ground path of the aircraft’s travel. The resulting signals are then fed into sensitive receivers developed by researchers at the University of Michigan and ProSensing, Inc., a Massachusetts company.

“There are different ways to build antennas to solve this problem, but array antennas provide multi-channel capability and greater sensitivity,” said Glenn Hopkins, a research engineer who headed up the GTRI design work. “Because this system is passive – it doesn’t send out radiation – we need to have maximum sensitivity and a focus on minimizing noise in the system.”

The HIRAD system, also known technically as a microwave synthetic aperture radiometer, is designed to operate in the microwave spectrum, from about 4 gigahertz to 7 gigahertz. Discrete parts of that range are used to enable discrimination between ocean surface emission and that from the rain located between the instrument and the surface.

“On the aircraft, the instrument would be flying a track over the storm, with a multitude of simultaneous beams,” explained Hopkins. “We would be pixelating the surface and could determine what radiation is coming from each area to generate a map of the intensity of the wind speeds as we fly over the storm.”

Beyond supporting the radiometer’s need for high sensitivity and low noise, the component also had to be as small and light as possible to be part of the Global Hawk payload. The GTRI design was manufactured by an outside company, and integrated directly onto the back of the instrument’s antenna. The circuitry is just 20 one-thousandths of an inch thick, printed on flexible circuit materials.

“This project is an example of the kinds of work we have been doing for the Department of Defense, and we’re pleased that this technology can be transitioned to assist with weather prediction and research,” Hopkins said.

As part of a small business innovation research (SBIR) project with Spectral Research, Inc., GTRI researchers also participated in an effort to increase the capability of the HIRAD array by designing a dual polarized array to replace the single polarized array that is part of the existing test system. The dual polarized array operates at the same 4 to 7 gigahertz range as the single polarized array, but provides both polarization channels in the same area.

The dual polarized design exploited fragmented antenna technology developed at GTRI to support this broad range of frequencies.

“One key challenge in the array study was to use the same footprint as the single polarization array,” said Jim Maloney, a GTRI principal research engineer. “Prototype dual polarization arrays were built and measured to confirm the ability of GTRI’s fragmented antenna technology to meet the bandwidth and form factor requirements.”

The Global Hawk can fly at altitudes of more than 60,000 feet, and can stay in the air for as long as 31 hours, allowing it to remain in the hurricane area as much as four times longer than piloted aircraft now used for monitoring hurricanes. It provides data that is more detailed than what satellites could provide.

“A UAV is able to stay over the storm for much longer,” Miller noted. “Compared to a satellite, the UAV observations are of much higher spatial resolution, and depending on the satellite’s orbit, generally of a much longer time period. A satellite instrument would be able to observe storms continually, over a much larger area, but would provide much coarser spatial resolution.”

Development of HIRAD was supported by NASA and the National Oceanic and Atmospheric Administration (NOAA). The project involved partnerships among NASA’s Marshall Space Flight Center, NOAA’s Unmanned Aerial Systems Program, the University of Michigan, the University of Central Florida and NOAA’s Hurricane Research Division.

Research News
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Media Relations Contacts: John Toon (404-894-6986)(jtoon@gatech.edu) or Lance Wallace (404-407-7280)(lance.wallace@gtri.gatech.edu).

Writer: John Toon