Interferometry Program Flight Experiment #1: Objectives and Results

The Interferometry program EXPeriments (IPEX) I and II are a series of flight experiments designed to characterize microdynamics of structures in space. Of particular interest is potential thermal snapping when space structures undergo rapid thermal variations, such as a sun-to-shade transition. This information is needed to characterize uncontrollable high frequency disturbances in future space interferometry missions. Both experiments are performed on the German DARAIDASA free-flying platform Astra-Spas, which is sortied out of the shuttle with the robot arm and retrieved after a 10-day mission. IPEX-1, performed dunng the STS-80 mission in December 1996, was a suite of 12 micro-g accelerometers which monitored the on-board dynamics of the Astra-Spas during normal operations and quiescent periods. The paper will report the results of the IPEX-1 flight experiment. The paper will also describe the second flight experiment, IPEX-11, which will be performed during the STS-85 mission in August 1997, and will monitor the microdynamic behavior of an AEC-ABLE mast.