Latest Developments in the Advanced Photovoltaic Solar Array Program

In 1985, the Jet Propulsion Laboratory (JPL), under sponsorship from the NASA Office of Aeronautics, Exploration and Technology (OAET), initiated the Advanced Photovoltaic Solar Array (APSA) Program to demonstrate a producible array system by 1990 with a specific power greater than 130 W/kg at a 10 kW (BOL) power level. This establishes an intermediate near-term goat in anticipation of the eventual need by the year 2000 for an array with a specific power of 300 W/kg at a power level of 25 kW (BOL). The near-term goal represents a significant improvement over existing rigid panel flight arrays (20 to 40 W/kg), the first-generation flexible blanket NASA/OAET SAFE I array of the early 1980s which was projected to provide about 66 W/kq (BOL), and the proposed flexible blanket arrays for Space Station Freedom at 40 W/kg (BOL). The latest program phase completed fabrication and initial functional testing of a prototype wing representative of a full-scale 5 kW (BOL) wing (except truncated in length to about 1 kW), with weight characteristics that could meet the 130 W/kg (BOL) specific power goat using thin silicon solar cell modules and weight efficient structural components. This paper continues the status reporting on the program presented in the last three IECEC symposia. The wing configuration and key design details are reviewed along with results from key component-level and wing-level tests. Projections are shown for future performances enhancements that may be excepted through the use of advanced solar cells and structural components. Performance estimates will be shown for solar electric propulsion orbital transfer missions through the Van Allen radiation belts. The latest APSA program plans are presented.