LIDAR for Asteroid Explore Hayabusa: Development and on Board Evaluation

Hayabusa, launched May 2003, is the first Japanese spacecraft to explore the small asteroid Itokawa (1998SF36) and touched down on Itokawa twice to sample of the surface material. LIDAR (LIght Detection And Ranging) is an important navigation sensor for the asteroid explorer to measure distance between the spacecraft and the asteroid. Since it is carried in a planetary exploration spacecraft, the weight of LIDAR is very lightweight of 3.7kg. In the rendezvous and touchdown operation, LIDAR supplied the ranging data to the spacecraft navigation system to approach Itokawa down to 50m and its total shots number of laser pulse was more than 4 million. The composition and basic performance of LIDAR are explained and this paper also reports the ranging data at the time of landing to asteroid Itokawa of the autumn of 2005.