DARPA to Recycle 'Graveyard' of Satellites

The orbit of GEO satellites is about 20,000 miles further from the surface than the International Space Station, which NASA discovered is better for communication because a high orbit allows satellites' speed to closely match the rotation speed of Earth. Photo: NASA

The Defense Advanced Research Projects Agency (DARPA) is planning to recycle billions of dollars worth of non-working satellites that float in a “graveyard” above our planet, the agency announced last week.

Right now, more than $300 billion worth of satellites are drifting through space in geosynchronous orbit (GEO) – or 22,000 miles from Earth’s surface – but many of these have been “retired” due to normal end of useful life, obsolescence or failure.

Retired satellites are typically put into a GEO-disposal or “graveyard” orbit, but many of them still have working component parts. Through its Phoenix Program, the agency plans to harvest antennas and other components from retired satellites and reuse them in new projects – a move that could save the Defense Department millions of dollars, DARPA said.

“If this program is successful, space debris becomes a space resource,” said Regina E. Dugan, director of DARPA.

Today, the Defense Department spends millions of dollars to deploy new replacement satellites, and one of the biggest expenses is launch costs, which depends on the weight and volume of antennas.

Repurposing antennas from retired satellites already in orbit would dramatically reduce launch costs and keep working components from going to waste, DARPA said.

While the idea of recycling satellite parts sounds promising, the technology needed for GEO recycling still needs some work, the agency said. Since the harvesting and reattaching of parts will take place while satellites are still in orbit, advanced robotics will be needed to put the plan in motion.

“Satellites in GEO are not designed to be disassembled or repaired, so it’s not a matter of simply removing some nuts and bolts,” said David Barnhart, DARPA program manager. “This requires new remote imaging and robotics technology and special tools to grip, cut and modify complex systems.”

“For a person operating such robotics, the complexity is similar to trying to assemble via remote control multiple Legos at the same time while looking through a telescope.”

To get the job done, the agency plans to build on technology that already exists – like a ground-based robotics system that allows surgeons to perform telesurgery on a patient thousands of miles away and advanced remote-imaging systems that can view the ocean floor through thousands of feet of water.

If reengineered for zero-gravity, high-vacuum and harsh radiation, these technologies could be used to collect and repurpose satellite parts in space, DARPA said.

Initially, DARPA will develop “satlets,” or nanosatellites, that can be sent in to orbit at low costs – likely by hitching a ride on commercial satellites. Through remote operating systems, satlets will harvest parts from nonworking satellites and attach them to replacements after they’ve been launched into orbit.

The agency hopes to eventually set up a “tender,” or satellite servicing station, to recycle parts and repair malfunctioning satellites in the long term.

DARPA said the success of the program depends on active participation from both the U.S. and international communities involved in advanced technology. The agency will host two industry days in November to give more information to interested participants.