A Landmark Based Position Estimation for Pinpoint Landing on Mars

~ b s t r a c t Real-time position estimation for a descent lander is a critical technological need for many of NASA's planned in situ missions including landing on a number of bodies at locations of greatest scientific interest and sample return. In particular, it enables the capabiliq to land precisely and safely in a scientiJically promising but hazardous site and is a key technology to be demonstrated by NASA in the next decade. The key challenge of pinpoint landing (PPL) is how to localize the lander by recognizing the landmarks (craters) in the landing area and match them positively to a preexisting landmark database while the spacecra$ is descending. In this paper, a real-;ime landmark based position estimation technique for pinpoint landing is suggested. This system includes three crucial components: ( I ) realtime landmark detection, (2) real-time landmark matching and (3) state (both position and velocity) estimation. We discuss the peformance anaIysis of this system. Finally, we show that the suggested technology is able to deliver a spacccraj6 tc less thar. 100 m from a pre-selected landing site on Mars.