A Concept For Elimination Of Small Orbital Debris

A concept for forced reentry of small orbital debris with characteristic dimension ~ 10 cm from the highly populated sun synchronous orbit by injecting micron scale dust grains to artificially enhance drag is discussed. The drag enhancement is most effective when dust grains counter rotate with respect to the debris resulting in hypervelocity dust/debris impacts. While the natural drag on small debris with ballistic coefficient ~ 5 kg/m2 in orbits with perigee above 900 km is negligible, it is sufficient to decay the orbit of the injected dust grains at a significant rate. This offers a unique opportunity to synchronize the rates of descent of the dust and debris to create a sweeping (snow-plow-like) effect on the debris by a descending narrow dust layer. The dust density necessary to de-orbit small debris is sufficiently low such that the orbits of active satellites which have larger ballistic coefficients are minimally affected. If deemed necessary, contact of the injected dust with active satellites may be avoided by maneuvering the satellite around the narrow dust layer.