William R. Clayton

Optical components for solar and laser thermal bimodal propulsion and power systems

The use of Solar Thermal Propulsion (STP) as an upper stage propulsion system requires the use of large primary concentrators. The size of the primary concentrators, ranging in size between 2–10 meters in diameter, depends upon the configuration of the propulsion system. Three concepts being pursued for the concentrators are inflatable, foam rigidized, and rigid concentrators. Inflatable concentrators are deployed by inflation, and their shape is maintained by a pressure inside the concentrator canopy. Foam rigidized concentrators are deployed by inflation. They differ from inflatable concentrators, in that they are rigidized by a foam which is injected between two membranes. This paper will discuss the current state of the technology for the fabrication and use of inflatable and foam rigidized concentrators and integration of these concentrators into an optic system. The use of a secondary concentrator to integrate the primary concentrator with an absorber system will also be presented.