Solar Thermal Technologies for Orbit Transfer Vehicles and Space Mobility

Physical Sciences Inc. proposes to develop an innovative solar thermal propulsion system for application to orbit change and mobility for small spacecrafts. In the proposed Phase II program an engineering system will be built and tested. In the proposed system solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the optical waveguide transmission line consisting of low-loss optical fibers. The optical waveguide cable transmits the high intensity solar radiation to the thermal receiver for efficient, high performance thrust generation. The features of the proposed system are: 1) highly concentrated solar radiation can be transmitted via flexible optical waveguide transmission line to the thruster's absorber cavity; 2) the flexible optical waveguide linkage de-couples the thruster from the concentrator to provide freedom from the constraints of previous solar propulsion system designs; 3) the configuration of the solar receiver can be optimized for efficient heat transfer with minimal re-radiation loss; 4) aiming and tracking for the concentrator become significantly easier by moving the termination of the optical fiber cable to follow the focal point of the concentrator; and 5) high intensity solar radiation can be switched to different receivers to deploy several thermal thrusters as necessary.