Inflatable, Rigidized Collectors and Related Components for Solar Thermal Propulsion

Solar Thermal Propulsion (STP) and Integrated Solar Upper Stage (ISUS) concepts are being evaluated which may have significant technical and economical benefits for transporting payloads to higher energy orbits. The performance and economy of solar thermal propulsion in this application are dependent upon deployable solar collectors of low weight and high accuracy. Collectors in which the optical shape is maintained via pressurization is a primary candidate; however, this approach involves risks from meteoroid or debris damage. A candidate approach to reduce this risk, involving foam-rigidizing the reflector surface after deployment, has been proposed by SRS Technologies and Thiokol Corporation. Inflatable concentrators have a long history of interest for use as large space structures due to the high packaging efficiency and simple deployment. However, gas inflated structures deployed on long term missions require make-up gas due to the inherent permeability and leakage caused by punctures from small particle impacts. This proposed effort will exploit recent successes in constructing inflatable concentrators and foam rigidizing efforts. The proposed work consists of foam shrinkage minimization and in-vacuum inflatable concentrator deployment and foam rigidization. Optical testing in vacuum will be performed to characterize the shape of the concentrator after inflation and rigidization.| Benefits: A higher performance and lower cost means for delivering payloads will be of benefit for both government and commercial payload launches. The film fabrication technologies are being applied in the commercial market of transparent aircraft canopies, composite molds, and commercial film manufacturing.|