WASHINGTON — NASA’s Marshall Space Flight Center is gathering information for the possible development of a demonstration satellite to track pieces of orbital debris that are too small to be seen by current systems but still pose a threat to operating spacecraft. Spurred by the new U.S. National Space Policy that emphasizes tracking and mitigating orbital debris, Huntsville, Ala.-based Marshall may partner with industry and academia to field a low Earth orbiting satellite as soon as 2014, said Bruce Wiegmann, an engineer in Marshall’s Advanced Concepts Office (full story at http://www.spacenews.com/civil/101022-marshall-ponders-debris-tracking-demo.html)
This is an interesting concept, as, in my opinion, there isn't enough of this going on at the moment. Debris in GEO is not as well modeled as lower orbits because of the difficulties of tracking stuff that far away; but there are only a few satellites being used to obtain data on GEO (at least as I understand the situation).
This demo satellite is aimed at tracking debris from 1-10 cm in diameter, what's known as the medium-sized class. The stuff above 10 cm is well tracked from Earth. The problem with the medium debris size class is that collision with a piece can cause a lot of damage to a functioning spacecraft, and even mission failure. And there's far more of it than the big stuff, so collision is far more likely.
I will have to keep an eye on this development to see if there are implications for space heritage.