  Understanding dust dynamics in the vicinity of asteroids is key for future
science missions and, in the long-term, for asteroid exploitation. This paper
analyzes the feasibility of manipulating asteroid material by means of solar
radiation pressure. A novel method is proposed for passively sorting material
as a function of its grain size or density, where solar radiation pressure is
used as a passive in-situ "mass spectrometer". A simplified analysis shows that
in principle this method allows an effective sorting of regolith material. This
could have immediate applications for a sample return mission, and for
industrial scale in-situ resource utilization to separate and concentrate
regolith according to particle size or composition.
