On-orbit validation of the roll-out solar array

The Roll-Out Solar Array (ROSA) is an unfurlable solar panel system that was flight tested on the International Space Station mobile servicing system during a seven day mission following a June 3, 2017 launch on the SpX-11 commercial resupply mission. On June 18, the wing unfurled as planned to the full 5.4 meter length under the power of the stored strain energy in the composite slit-tube booms. The two booms and a thin mesh blanket with III-V photovoltaic cells simultaneously unrolled themselves into a stiff, tensioned state in only a few minutes time. This space flight test confirmed the mechanisms and booms performed well after 10 months of storage, launch, and 215 on-orbit thermal cycles. Following deployment, the wing structural dynamics was measured and the mode shapes of fundamental vibration were observed in the heat of orbital daylight and the cold of night. Finally the power conversion efficiency of the III-V solar power modules was measured to be nominal before and after three complete deployment and retraction cycles at the end of the mission. This mission has validated analytical structural models and proven the robustness of this new class of deployable solar array. Due in part to this mission success, a scaled up version of ROSA is being planned for commercial use by multiple vendors including by Space Systems Loral on their 1300 series satellites.