ALBUQUERQUE, N.M. — It’s a lesson every kid learns: clean up after yourself.
A Colorado company and the Air Force Research Laboratory in Albuquerque are trying to put that advice to work when it comes to outer space.
The laboratory, in partnership with MMA Design LLC in Colorado, has come up with a device to keep spacecraft from adding to the man-made junk that buzzes around in low-Earth orbit.
Called the dragNET, it drags spacecraft back into the atmosphere faster than the pull of gravity alone. It can force re-entry of satellites and launch vehicles by 30 to 50 percent faster than craft that rely just on gravitational pull to return to Earth’s atmosphere, where they burn up.
The dragNET works like a parachute attached to the back of a race car. It’s basically a compact, lightweight membrane, or thin film, that is stored in a box attached to spacecraft. It deploys once a satellite has reached the end of its life, or in the case of a launch vehicle, immediately after reaching space.
The stored material springs outward into a square shape and remains attached to the craft. That adds drag as the craft continues to orbit, said Mitch Wiens, MMA president and chief operating officer.
“It’s stored in a box essentially, and the sides unfold once the restraint is released,” Wiens said. “The four legs of the structure spring out radially, allowing it to unfold into a full sail. It’s stored in a telephone book-sized box when it goes up, but it spreads out up to 24 square meters once fully deployed, creating enough extra drag to cause a change in orbit to help get the vehicle down quicker.”
The device adds only about six pounds to spacecraft, greatly reducing the costs for using it, said Lt. Col. Steve Lindsay, program manager for the dragNET project at the research lab’s Space Vehicles Directorate.
“It’s very lightweight and it has lots of flexibility to scale up and down as needed for small or large satellites and launch vehicles,” Lindsay said. “It’s designed for low-Earth orbit of between 99 and 1,200 miles out. That’s where you can still have drag before getting too high up outside the pull of gravity.”
Trash clean-up is critical in that range. Some 11,000 pieces of debris are in low-Earth orbit, thanks to fragments created by collisions among space junk and on-board explosions on spacecraft. That creates significant risk to satellites and other vehicles.
The dragNET won’t shrink the field of debris already in space, but it can help slow the growth of space trash, said Benjamin Kyle Henderson, chief of the spacecraft component technologies branch of the Space Vehicles Directorate.
“If we don’t clean up the junk we put up, it can impact something else up there and create even more junk,” Henderson said. “We want to be good custodians and clean up after ourselves. We need to be good neighbors.”
The U.S. Department of Defense has set a 25-year deadline for military-launched craft to return to Earth’s atmosphere once vehicles stop working. The dragNET can help meet those goals, while providing a useful tool for other government agencies and commercial launch operators as well.
MMA designed the dragNET with nearly $900,000 in Department of Defense Small Business Innovation Research grants, plus funding and technical assistance from the Space Test Program at Kirtland Air Force Base. The dragNET was integrated in Albuquerque onto both a military satellite and its launch vehicle, which went to space in November 2013.
The dragNET was deployed immediately on the launch vehicle, helping that craft return from orbit in December 2015. The Starfire Optical Range at Kirtland, which houses high-powered telescopes capable of tracking and photographing satellites and other craft, followed the launch vehicle to confirm the dragNET deployed as planned,
The dragNET is now stored on the satellite still in space, awaiting deployment.
“We’re operating that satellite from here in New Mexico,” Lindsay said. “We’re not just testing the dragNET. We’re using it as part of a space mission.”