MOP:: A space debris and interplanetary dust sample return mission

Our knowledge of the dynamics and composition of interplanetary dust particles is mainly based on theoretical models. Only for a few dust grains that were captured in low Earth orbits (< 2000 km) the composition and mineralogy has been studied. The additional contribution of space debris at low altitudes is rather well understood, but the flux of small space debris in higher orbits could not yet be determined. The MOP spacecraft will have a geostationary transfer orbit (i.e. an apogee distance of approximate to 42000 km) and will collect on aerogel plates both species, the interplanetary as well as the artifical grains in high altitudes far away from atmospheric influence. After a reentry manoeuvre, these particles can be investigated in laboratories on Earth. Their traces in the aerogel can be used to determine velocities and impact directions. Moreover, the MOP satellite will carry a new instrument to detect in-situ nano-particles, i.e. particles with masses in the range between 10(-17)-10(-21) grams. Thus, for the first time, the MOP mission will provide direct information (a) on interplanetary dust particles and space debris in high altitudes up to geostationary orbits, (b) on their phase space vectors, and (c) on the fluxes of nano-particles.