Performance Measurements of the Submillimeter Wave Astronomy Satellite (SWAS) Solar Array Deployment System

This paper discusses some unique features of the solar array deployment system used on the Submillimeter Wave Astronomy Satellite (SWAS). The mechanism system is highly optimized, incorporates no single-use components, and is fully testable in a one-"g" environment. A single High Output Paraffin (HOP) linear actuator drives the mechanisms used to deploy and lock each wing of solar array panels. The solar arrays open slowly, requiring only enough force to overcome inefficiencies and friction. Load cells measure the force required to open the solar arrays. The system's margin is easily determined by comparing the maximum capability of the HOP actuator to the load cell readings. The method of direct measurement of the force required to open the solar array makes this system unique. These measurements account for, but do not differentiate between sources of friction, misalignment and inefficiency. During assembly these measurements helped simplify hinge alignment. Throughout the environmental test program, they were used to identify failures, and over time, they helped indicate any degradation of the mechanisms. Additional performance data will be available after the solar arrays deploy in orbit. SWAS is scheduled to launch in 1995 on a Pegasus-XL launch vehicle.