Modular solar array flight experiment: A platform for rapid technology evaluation

The need to test new space solar array systems within their combined effects operational environment persists. Previous flight experiments have characterized cell electrical behavior, yielding valuable degradation and performance information-at the cell level. Unfortunately, many space vehicles experience failures at a higher level of integration. The Air Force Research Laboratory (AFRL) continues to invest in advanced cell, string, and structural technologies for solar arrays, which must be validated as a complete assembly within the space environment. This paper outlines engineering objectives and flight configuration for the Modular Solar Array (MSA) flight experiment. MSA in this application serves as an experimental platform but was also designed to address the current, labor intensive practice of fabricating custom solar arrays. This is accomplished by standardizing the module´s mechanical and electrical interfaces while retaining high photovoltaic cell packing factor. Commonality among modules facilitates rapid power system design, damaged module replacement and new technology insertion. As such this flight experiment has two principle thrusts: ground demonstration of the flexibility of modular architectures, and acquisition of string level performance data within a near earth orbit. The on-orbit data gathered will be compared to ground test data to improve confidence in scaling MSA for use on LEO, GEO spacecraft. **MSA is one of four experiment packages on STPSat-4, a free flying spacecraft ejected from the international space station. Launch is scheduled for late 2016.