Description: This Phase IIE program will demonstrate an innovative, module-level encapsulation technology that will lower encapsulation costs by up to 90% and enhance the performance of space-grade solar arrays. Conventional solar cells for space use specialized coverglass that provides essential environmental protection from high-energy particle and ultraviolet solar radiation but is expensive to apply and has high fragility. Next-generation coverglass replacement materials have been explored by several groups over the past decade. For example, pseudomorphic glass (PMG) uses glass microbeads embedded in a silicone matrix that can be formed into sheets or sprayed on interconnected modules. This flexible encapsulation is synergistic with the thin-film, inverted metamorphic multi-junction (IMM) solar cells currently manufactured by MicroLink Devices, enabling a pathway to truly flexible solar modules. The central challenge to using silicone-based encapsulations such as PMG is to provide suitable protection against UV degradation. In the Phase I and II efforts MicroLink has demonstrated a low-cost dielectric coating process that protects the silicone from UV as well as atomic oxygen. The coating is enabled by the prismatic texturing of the silicone surface, which also provides an important improvement in optical transmission of up to 4%. This process was developed using expensive, space-grade silicones that include DC 93-500. In this Phase IIE program, MicroLink will expand this work to include a broader range of silicone and fluoropolymer materials that will have a cost structure that is 10x lower, while continuing to meet NASA outgassing requirements. MicroLink will also explore new module fabrication approaches that can further mitigate outgassing and exceed NASA requirements by 10X, for potential use in missions with high sensitivity to outgassing.

Benefits: Spacecraft, Lunar and Planetary Missions – Lightweight, flexible roll-up power modules for Lunar VSAT. Large-scale SEP (solar electric propulsion) spacecraft with high specific power solar arrays for a variety of NASA science missions. Satellites – The IMM solar modules are low cost and have low mass with high output power and will be beneficial for large-scale deployment of constellation satellites.

Unmanned Aerial Vehicles (UAVs) – High-altitude long-endurance (HALE) solar UAVs such as the Airbus Zephyr, which have variable sun incident angles depending on time of day/year & latitude. Commercial Satellites – Flexible “roll-out” arrays, LEO constellation satellites that require low cost and visibility for reduced light pollution. Textured sheets can be applied to all solar cell technologies.