DARPA’s investments are aimed at addressing key challenges associated with the skyrocketing costs and complexity of launching large satellites. The research arm also is focused on the challenge of space situational awareness, or tracking objects in space.

Rethinking satellite size is a big government priority, given that a typical U.S. Department of Defense satellite today takes as long as two decades to launch from the time it’s conceived, says David Neyland, director of DARPA’s Tactical Technology Office. “On top of that, you have got the cost of getting these (satellites) into orbit, which is typically $200 million to $400 million to launch.” That’s the impetus behind DARPA’s System F6 (Future, Fast, Flexible, Fractionated, Free-Flying Spacecraft United by Information Exchange) program, which looks at the feasibility of building fractional spacecraft that focus on a single capability (data processing or storage, communications, imaging). These wirelessly-interconnected, smaller space modules fly in formation and share resources. “They’re all discrete separate satellites communicating across wireless communications and performing a function,” says Neyland. “The advantage of doing fractional spacecraft is they reduce the risk of launch. If one of the elements goes bad, you can replace it without affecting any of the other elements. We think in the long term that’s going to be a very cost-effective approach to tackling the problem of complexity and the cost per launch of these complex satellites.”

 

DARPA also is examining ways to lower the cost and risk of launching satellites, especially with the need for more frequent launches. Specifically, DARPA is revisiting horizontal launches, or launching payloads from existing turbojet aircraft from conventional runways. This launch approach, which relies on adding a liquid or solid propellant booster system as a second stage so it can launch the space asset into low-Earth orbit, was employed widely in the early days of manned spaceflight. “We think if we can do that, we open up an opportunity for commercial industry to get into launch operations in a big way because of the low-cost infrastructure. Our desire is for there to be no special infrastructure at all,” he says.

 

To address the space object tracking challenge, DARPA is testing its new Space Surveillance Telescope before handing it off as an operational system to the U.S. Air Force in 2012. The telescope will increase dramatically the amount of objects that can be tracked from low-Earth orbit to geosynchronous orbit, which DARPA estimates at about a million objects ranging in size from a BB to rocket bodies. Today, only about 20,000 objects are tracked by U.S. and worldwide telescopes. “Our space surveillance telescope will be able to detect objects all the way out to geosynchronous orbit that we couldn’t see before,” says Neyland, who hopes the technology will reduce the likelihood of incidents such as the Iridium-Cosmos collision that occurred over Siberia in February 2009. Neyland notes that the new tracking capability creates a data management challenge, since operators of the telescope now will have 50 times the data they had before. DARPA also is starting a follow-on program this year called Space Domain Awareness-Data Fusion, where it will take the data coming out of the telescope and “marry it with sensor data from other Air Force and civilian sensors, fusing them together to provide a comprehensive picture of what we can detect, see and track in orbit,” he says.

 

DARPA is not the only research entity committed to sensor-based tracking in space. The Space Dynamics Lab (SDL) at Utah State University Research Foundation developed the Wide-area Infrared Survey Explorer (WISE), which NASA launched into space in December 2009. “What excites me most about WISE is the number of new discoveries and the complexity of our instrument that functioned as planned,” says Niel Holt, director of SDL. NASA scientists “have discovered hundreds of asteroids and comets that had never been seen. The science community will be pouring over that data for decades.” SDL’s specialty is miniaturized sensors for small satellites. Increasingly, the technology is finding its way to the ground on small UAVs and even handheld UAVs that weigh less than a pound and are carried by soldiers, says Holt. “We have done work largely with the Naval Research Laboratory on ways we can miniaturize sensors and processing units so warfighters can get the data they need in near real-time.” 

 

 

Micro Gyros to Ease GPS Issues

Northrop Grumman is tackling another R&D challenge — low-power precision navigation in GPS-denied or GPS-challenged locations. The prime contractor is in phase four of a four-phase project for DARPA to further enhance the performance of a demonstration miniature navigation-grade gyro unit for DARPA. Once fully tested and fielded, it would give ground troops, vehicles and aircraft the ability to maintain precision navigation in urban or indoor environments. “Navigating very accurately and knowing your precise location is very important as we progress into the future. That’s not only true for satellite applications but also for soldier-borne applications,” says Doug Meyer, director, advanced sensor development, at Northrop Grumman’s Navigation Systems Division. Since October 2005, Northrop Grumman has been working on the DARPA NGIMG (Navigation Integrated Microgyro) program. The technology, which is based on atom physics, has been around since the late 1960s when first pioneered by scientists at Litton Industries (now part of Northrop Grumman). The breakthrough today is containing the atoms in a “very small gas cell” and using lasers to shrink the electronics dramatically, says Meyer. “It’s enabled us to take something that was for a single-gyro axis the size of two Coca-Cola cans stacked on top of one another to roughly the size of two sugar cubes stacked on top of one another.” Meyer estimates that it will be 2015 to 2016 before the gyro is in the hands of soldiers, and he also sees application for the technology with first responders such as firefighters who would be able to navigate in a GPS-denied environment such as a burning building.
 

 

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