Katharine Gammon, at Popular Science, reports on the DARPA Phoenix Project, to reuse of components of obsolete or non-working satellites, here,

Approximately 1,300 nonfunctional satellites sit in a graveyard orbit 22,000 miles above Earth—and DARPA has plans for them. Recycling dead satellite parts in space could be 10 times cheaper than building and sending up new satellites, says DARPA program manager Dave Barnhart. Earlier this year, the agency started the Phoenix project, which will use robots to salvage parts from decommissioned satellites as soon as 2015.

When a satellite in orbit 22,000 miles above earth fails it doesn’t fall to earth. And many components such as antenna and solar arrays,  remain functional. Rather then launch a spacecraft to ship a whole new replacement satellite into orbit, DARPA the Defense Advanced Projects Research Agency, the government agency that brought us the Internet. is planning on reusing these components – at 10% of the cost of a new satellite.