Remember the garbage-collecting Oscar the Grouch, from Sesame Street? Well, an orbital-debris-gathering spacecraft now bears his name. Known as OSCaR (for "Obsolete Spacecraft Capture and Removal"), the semi-autonomous craft is currently being developed at New York's Rensselaer Polytechnic Institute.

OSCaR will be a CubeSat, meaning that it will be a small, rectangular satellite.

In fact, it will be made up of three joined 10 x 10 x 10-cm (3.9-inch) CubeSat units. One unit will house its propellant and propulsion module; another will contain its data storage, GPS and communication systems; and another – the one in the front – will house four gun barrels that shoot out nets attached to tethers.

The idea is that multiple OSCaRs will be carried into orbit aboard larger spacecraft, and then released. Drawing upon a catalog of the locations of known bits of debris, each CubeSat will then head for one that's nearby, possibly with a small amount of remote guidance from an Earth-based operator.

As the OSCaR closes in on the debris, a combination of thermal, optical and radar imaging systems in its front unit will help it to target the item. It will then shoot out one of its nets, capturing the debris and holding onto it via the net's tether. Because the spacecraft will have four such nets, it'll be able to collect a total of four pieces of space junk per mission.

Once that mission is complete, the OSCaR will automatically steer itself out of orbit, burning itself and its collected debris up in Earth's atmosphere upon re-entry.

"There's an informal agreement that's been in place for a few years that people who put space objects up there should be practicing good citizenship," says Prof. Kurt Anderson, who is leading a student team that's designing the spacecraft. "We envision a day where we could send up an entire flock, or squadron, of OSCaRs to work jointly going after large collections of debris."