Solar-Powered Rocket Engine Optimized for High Specific Impulse.

摘要

Hercules Aerospace is currently developing a solar-powered rocket engine (SPRE) design optimized for high specific impulse (lsp). The SPRE features low loss geometry in its light-gathering cavity, which includes an integral secondary concentrator. The simple one-piece heat exchanger is made from refractory metal and/or ceramic open-celled foam The foam's high surface- area-to- volume ratio will efficiently transfer thermal energy to the hydrogen propellant The single-pass flow of propellant through the heat exchanger further boosts thermal efficiency by regeneratively cooling surfaces near the entrance of the optical cavity. These surfaces would otherwise reradiate a significant portion of the captured solar energy back out the cavity entrance. Such design elements promote a high overall thermal efficiency and hence a high operating lsp.