Description: Spacecraft for NASA, DoD and commercial missions need higher power than ever before, with lower mass, compact stowage, and lower cost. While high efficiency, space-qualified solar cells are in themselves costly, integrating them into a high performance Photovoltaic Assembly (PVA) using conventional glassing, interconnecting, stringing, tiling and laydown techniques can double their cost in $/Watt. The cost of solar power could be significantly reduced if the design of the Photovoltaic Assembly could be modified, modularized and standardized to be compatible with automated electronic assembly and terrestrial solar panel manufacturing methods. Additional benefits of such an approach include higher quality and consistency, improved qualification traceability, and robustness on thin flexible as well as rigid arrays. During the Phase I effort Vanguard successfully demonstrated automated pick-and-place, electrical interconnection, and adhesive dispensing adapted to our lightweight flexible Thin Integrated Solar (THINS) PVA. THINS uses multi-cell covers and advanced interconnection and encapsulation technology, which enables automated integration of traditional and advanced space qualified solar cells. Engineering economic analysis showed the potential for >30% PVA $/Watt cost reduction, while the encapsulation approach associated with THINS showed enhanced durability in space environments, even at high voltages and extreme thermal cycle environments. During the Phase II Program we will further enhance our automated sub-module manufacturing, and scale the approach to the module level. Automated assembly scale up will be performed while integrating into an existing deployable space structure platform, enhancing the TRL of a high performance high power application of automated cell integration scalable from tens to hundreds of kilowatts, and providing a credible commercialization path, all while reducing solar array costs by more than $150/W.

Benefits: Low cost, lightweight, high power solar arrays with compact packaging and high voltage capability is an enabling technology for meeting the key NASA objective of implementing solar electric propulsion, which enables enhanced planetary, human exploration, and orbit transfer missions. With these missions projecting prime power growth to 25 - 300kW, the automated assembly of THINS arrays with today's space qualified triple junction cells meets these needs with improved specific power by a factor of >3X, an improved volumetric efficiency when stowed for launch by a factor of >8X, and a PVA cost reduction of >30% compared to today's solar arrays. The approach additionally prepares for the low cost integration of IMM solar cells as they become qualified. These improvements, together with demonstrated high operating voltage capability exceeding 300V, allow an affordable high power system up to hundreds of kW to be packaged into a single launch. The THINS Array also has the advantages of improved high voltage stability and electromagnetic cleanliness because of surface continuity available from encapsulation, with similar technology developed at Vanguard already transitioned through a NASA Phase III SBIR to the Magnetospheric MultiScale (MMS) mission.

The trend towards Solar Electric Propulsion to supplant chemical propulsion for orbit-raising and station-keeping, and the advent of "all-electric" spacecraft which use SEP for orbital transfer and stationkeeping, have driven the need for both higher power and higher voltage in commercial and DoD spacecraft. Commercial spacecraft have trended toward higher power to also provide more capability (e.g. more bandwidth or coverage) which translates directly to increased revenue for the spacecraft operator. Additional functionality for military spacecraft, including enhanced communication, reconnaissance, and on-orbit computational capabilities, as well as the maneuverability afforded by SEP also drive to higher power requirements. The implementation of a low mass, low volume, low cost array with improved cost and environmental robustness benefits all of these applications.