A TESTBED FOR THE MSX ATTITUDE AND TRACKING PROCESSORS A Testbed for the MSX Attitude and Tracking Processors

he Midcourse Space Experiment (MSX) spacecraft employs infrared, ultraviolet, and visible light sensors to collect images and spectrographic signatures on a variety of targets, especially missiles, other satellites, and auroral phenomena. These instruments are fixed in the satellite body and face in a common direction. Their fields of view vary, with some of them being quite small (1 3 3°). Thus, as MSX travels in its orbit, the entire satellite must be precisely rotated to keep the target in view. In fact, a pointing accuracy requirement of 0.1° was imposed on the satellite’s design. To help meet this requirement, APL designed and built an elaborate testbed for the key elements of the MSX attitude and tracking subsystems. The testbed provides the means to assess the performance of these subsystems through simulations of missile encounters and other data collection events. T