The Mobile Asteroid Surface Scout (MASCOT) - System & Mission Engineering and Surface Operations Concept

The Mobile Asteroid Surface Scout (MASCOT) is currently under development as a DLR contribution to the Japanese Hayabusa 2 mission, a sample return mission to the C-type near-Earth asteroid 1999JU3. MASCOT is a small about the size of a shoe box deployable package with a total mass of 10 kg. It enhances the missions scientific return by providing ground truth information from different surface sites by relocating itself with a hopping mechanism. It is, thus, complementing the sample return mission. MASCOT will also accomplish stand-alone science which can only be provided by a surface element and will serve as reconnaissance and scouting vehicle. Challenges to the design of a small-body landing package are the geo-technical properties of these bodies, which are a priori basically unknown. The shape and rotational state is assumed to be irregular, resulting in a complex gravity field, whereas the surface properties could even differ largely across the surface of one asteroid. The marginal knowledge of the environmental conditions affects mainly the mobility capabilities and guidance control performance. To fulfill its mission objectives while satisfying the tight mass and volume budget constraints in view of a highly uncertain environment, MASCOT is designed as a highly integrated small landing package with some degree of autonomous robotic operations capability on the asteroid surface. This paper introduces the system design as well as the payload suite of MASCOT and then focuses on mission design aspects and the surface operational concept. Hereby, the interaction of the mobility subsystem, the attitude motion determination sensors and the payload, coordinated by MASCOT's onboard decision making entity, is discussed. An outlook to functional endto-end simulation and testing is given.