Have you ever wondered what we are doing with all those old satellites orbiting the earth, which are now no more than space junk? Usually they are simply left inoperable and are worthless, however, now researchers from DARPA (Defense Advanced Research Projects Agency, USA) have a novel idea. They want to refit and reuse them. 

"Today, when a communication satellite fails, it usually means the only solution is the expensive prospect of having to launch a brand new communication satellite to replace the old one," DARPA's Phoenix Program web page says. 

Their plan is to use small mini-satellites, called "satlets", which will attach themselves to large parts of the old non-working satellites, currently in geosynchronous orbit (GEO) above earth.  They include such objects as antennas and solar arrays. The plan is to remove them and then take them to a spacecraft for servicing, where robotic arms controlled from earth, will use them to build a "new" satellite. The project, named Phoenix, is planned to go into operation by 2015. 

"The goal of the Phoenix program is to develop and demonstrate technologies to cooperatively harvest and re-use valuable components from retired, nonworking satellites in GEO and demonstrate the ability to create new space systems at a greatly reduced cost."