Pointing mechanisms for the Shuttle Radar Laboratory

In December of 1993, the Shuttle Radar Laboratory (SRL) is scheduled for launch on the first of its two missions. The SRL has three major radar instruments, two distribute phased-array antennas that make up the Spaceborne Imaging Radar-C System (SIR-C) and are capable of being electronically steered and one which is an X-Band Synthetic Aperture Radar which is pointed mechanically by a suite of mechanisms, This paper will describe these mechanisms and summarize the development difficulties that were encountered in bringing them from the design stage through prototype development and testing. INTRODUCTION The SRL is a Space Transportation System (STS or Space Shuttle) borne imaging radar laboratory that will be used in global scientific studies in geology, hydrology, ecology, oceanography and meteorology. The laboratory is the most massive flight instrument system ever designed, fabricated and assembled at the Jet Propulsion Laboratory Its mass is 10,400 kg including electronics ...