Description: Proposed is the development and validation in a laboratory environment of a photovoltaic (PV) array design of unique and enabling characteristics. Namely, smoothly deployed from compact stowage with one single, continuous sweep of motion, a total PV surface area up to and beyond 4000~m2 (the area associated with 1~MW power) is provided by two wings, with mechanical performance objectives also met. The PV cells are mounted on flexible strups that, assembled, constitute array disk pie segments between straight ribs and smoothly wrap between the latter on the central hub for stowage. The surface shears in stowage effected by this kinematics are absorbed by shear compliant hinge strips between the strips, and the PV cells are mounted on the latter ro precisely align in the roll. Deployed, the surface segments between the ribs are pretensioned with catenaries on the outer perimeter, supported by the rib tips which extend outward. A full mechanical design is developed to complete concept validation for a pair of wings 2000 m2 each, fabrication and operational issues are explored and addressed, and a working prototype wing is built to complete concept validation.

Benefits: NASA has been spearheading the strategy to develop a robust and advanced space infrastructure that, in the foreseeable future, could support the extensive exploration of the solar system and render human presence in space sustainable and affordable. One of the key technologies in this drive is solar electric propulsion (SEP), a technology with a mass efficiency an order of magnitude higher than conventional chemical engines. SEP which has already supported some missions (e.g., Deep Space 1 in 1998 and Dawn in 2007) will revolutionize navigation (i.e., velocity change, orbit revision) capabilities for spacecraft of traditional architectures. However, to be powerful enough to support equipment on a scale necessary for the infrastructure behind human presence is space, SEP has to be scaled up which directly requires solar arrays capable of producing up to 1~MW of power, the long term goal targeted by this NASA solicitation. It is this future market (currently) driven by NASA for large solar arrays that the product developed by the presently proposed effort targets.

For the large solar array structure here proposed, markets other than what has just been outlined will also arise. Some non-scientific space applications such as defense (the military use of space) and planetary defense (defending Earth against impact by space objects such as asteroids) have traditionally time and again entertained power-hungry mission scenarios. With the actual availability of a light weight, reliable, and easily scalable truly large solar array such as the one herein proposed, actual needs for this product in these additional markets will certainly arise.