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.