Asteroid sample and return spacecraft WSES-C has some newly-developed light weight optical sensors, in order to approach, rendezvous with, and land on the asteroid 1989ML. ONC-T is a multi-spectrum optical band camera with 8 filters, 5.7degrees x 5.7degrees FOV, and 20 arcsec/pixel resolution. It is used for scientific observation and the precise global mapping of the asteroid to select a landing point. Both ONC-W1 and W2 are wide angle camera with 60degrees x 60degrees FOV and used for autonomous guidance onboard. LIDAR is used for measurement of distance to the asteroid surface from 50 km to 50 m. LRF provides relative distance and attitude to the asteroid surface using four beams at the range less than 100 m. Four sets of FBS detect obstacle under solar cell panels to avoid unexpected collision to the surface. In this paper, after brief description of rendezvous and landing scenario, aims, requirements, and design specifications of each sensor are shown. Present status of development, function and performance test results of some prototype sensors are also reported. (C) 2002 Elsevier Science Ltd. All rights reserved.
