Patent ID: 7637457

Claim:
An aircraft powered by the heat of the sun comprising: an aircraft body; a Rankine-Brayton hybrid thermodynamic cycle heat engine carried by said aircraft body for producing power, said heat engine having a pump for pressurizing a sub-critical pressure liquid-phase working fluid to a supercritical pressure; heat storage means for storing thermal energy and using the stored thermal energy to heat the supercritical pressure liquid-phase working fluid to a supercritical temperature, supercritical pressure phase; an expander for substantially isentropically expanding the supercritical temperature, supercritical pressure working fluid to reduce the pressure of the working fluid back to a sub-critical pressure level; and an air-cooled condenser in thermal contact with the ambient environment for condensing the sub-critical pressure working fluid back to the sub-critical temperature liquid phase; propulsion means powered by said heat engine means for enabling sustained flight of said aircraft; solar concentration means movably connected to said aircraft body for receiving and concentrating solar energy; solar tracking means including means for determining whether said solar concentration means is optimally aligned with the sun, and means for actuating said solar concentration means into optimal alignment with the sun based on said determination; and heat collection/transport means for collecting the concentrated solar energy and transporting heat to said heat storage means.