600 Volt Stretched Lens Array for Solar Electric Propulsion

Over the past six years, ENTECH, Auburn, NASA, and other organizations have developed a new space photovoltaic array called the Stretched Lens Array (SLA), which offers unprecedented performance (e.g., >80 kW/cu.m. stowed power, >300 W/sq.m. areal power, and >300 W/kg specific power in the very near term) and cost-effectiveness (>75% savings in $/W compared to planar high-efficiency arrays). SLA achieves these outstanding attributes by employing flexible Fresnel lenses for optical concentration (e.g., 8X), thereby minimizing solar cell area, mass, and cost. SLA's small cell size (85% less cell area than planar high-efficiency arrays) also allows super-insulation and super-shielding of the solar cells to enable high-voltage operation and radiation hardness in the space environment. Recent studies show that SLA offers a 3-4X advantage over competing arrays in specific power for many NASA Exploration missions. ENTECH and Auburn, with Aerojet support, propose to develop and demonstrate a special version of SLA, specifically optimized for Solar Electric Propulsion (SEP) missions. This SLA for SEP will operate at 600 V to direct-drive an Aerojet Hall-effect electric thruster. Such a combination of an ultra-light, high-voltage, radiation-hard SLA with a high-specific-impulse electric thruster will have widespread applicability to many NASA, DOD, and commercial missions.