Abstract: A thermal solar rocket that includes a solar energy receiver having two sections (a thermal energy storage section and a direct gain section), a solar concentrator, and a propulsion nozzle. In one embodiment, the focus of the solar energy between the storage section and the direct gain section is controlled by mechanical means such as movable insulation. In another embodiment, the focus of the solar energy between the storage section and the direct gain section is controlled by an optical switch in the form of relative motion between the solar concentrator and the solar energy receiver.

Abstract: A solar thermal rocket that includes a thermal energy storage section, a radiant inter-heater, a primary solar concentrator, and a propulsion nozzle. The primary solar concentrator is selectively movable to direct solar energy to either the thermal energy storage section or to the radiant inter-heater. The thermal energy storage section, along with insulation, is arranged to define a cavity such that a focused beam of solar rays can enter the cavity through an aperture in the insulation. The thermal energy storage section typically absorbs and stores solar energy during the non-propulsion portion of the orbital period. The solar rays are captured and absorbed and thereby heat the thermal energy storage section to very high temperatures. A radiant inter-heater directly receives concentrated solar rays and transfers the heat to the propellant during the propulsion phase.