There is—as you may have noticed from recent reports of giant objects falling from the heavens—a lot of junk in space. But all those retired satellites contain valuable parts, and there's no reason that they should be considered trash. So the Defense Advanced Research Projects Agency (DARPA), the government agency that plans on bringing us flying Humvees and mind-controlled prosthetic arms, has stepped in to figure out how to harvest components from dead satellites—and save the U.S. from spending excess cash and resources on brand-new ones.
The Phoenix program, launched this month, aims to robotically remove valuable parts from decommissioned satellites still in geosynchronous orbit, some 22,000 miles above Earth. Here's what DARPA envisions: a new class of nano satellites—adorably named "satlets"—could hitch a ride to orbit alongside commercial satellites. At the same time, a separate satellite-servicing satellite, decked out with remote vision and mechanical arms, could be launched into space. Once in orbit, the satlets could link up with the servicing satellite to become what part of what DARPA calls a "tool belt" for fixing up satellites.
Satellite antennas are large and require a lot of fuel to send up to space, so the servicing satellite could grab old (but functioning) antennas from dead satellites and attach them to the antenna-less satlets, generating a cheaper satellite pieced together from space junk and new parts.
This is no easy task. It requires all sorts of new technology from multiple disciplines—technology from medical micro-surgical tele-presence tools refashioned to work in space, for example. Nevertheless, DARPA hopes to have the ability to break off retired satellite parts using grappling tools controlled from Earth by 2015. It's an ambitious goal, but if any agency knows how to pull off a stunt like this, it's DARPA.
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