Numerical simulations of surface package landing on a low-gravity granular surface: application to the landing of MASCOT onboard HAYABUSA 2

Kurzfassung

The asteroid sample return mission, Hayabusa2 JAXA) was launched on December 3rd, 2014. It will reach the C-type near-Earth asteroid (162173) Ryugu in 2018 and bring back samples from its surface to Earth in 2020. Hayabusa2 will release the European (DLR/CNES) lander MASCOT (Mobile Asteroid SCOuT) on the asteroid surface to perform in-situ measurements [1]. Ryugu’s surface is expected to be composed of a gran- ular layer (regolith), whose physical properties are currently unknown. MASCOT’s behavior at landing, in particular its possible bounces, the traces left at the impact site, and the distance it may travel, will provide essential information about the nature of the regolith. To predict and support the landing site selection, as well as to be able to interpret the outcomes of the land- ing, we ran a first campaign of about 450 numerical simulations of MASCOT landing and interacting with Ryugu’s surface [2], accounting for its low gravity. Both MASCOT’s and the soil’s parameter spaces are investigated over a reasonable range to estimate their influences on MASCOT’s trajectory.