An autonomous navigation and guidance system for MUSES-C asteroid landing

摘要

ISAS plans to launch an asteroid sample and return spacecraft MUSES-C in 2002 and the spacecraft arrives at near earth asteroid 1989ML in 2003. To approach, rendezvous with, and land on the asteroid safely, the spacecraft has an autonomous navigation, guidance, and control system. That is, it has some functions of station keeping at the distance of about 20 km, landing guidance using optical camera and laser altimeter, hovering at about 20 m above the surface to synchronize the rotation of the asteroid and adjust touchdown attitude, and final descent control including obstacle detection and touch down sensing for reliable and safe collection of asteroid samples. In this paper, at first, the navigation, guidance, and control system onboard MUSES-C is presented, and then, rendezvous and landing scenario are described. Performance and robustness of the system are verified by numerical simulations, GRAphical computer Simulator (GRAS), and hardware simulator called TRAnslational Motion simulator (TRAM). A example of numerical simulation results and brief description of GRAS and TRAM are also shown.