Nuclear thermal propulsion system with reactor direct drive of cryocooler turbine

A method for operating a cryocooler turbine in a nuclear thermal propulsion (NTP) rocket, the method comprising:

• heating a first thermal working fluid via thermal communication of the first thermal working fluid with a nuclear reactor core of the NTP rocket;
• circulating the first thermal working fluid along a first fluid circuit to the cryocooler turbine of a cryogenic fluid management (CFM) system;
• driving the cryocooler turbine with the heated first thermal working fluid;
• driving a first compressor of the CFM system via a shaft rotated by the cryocooler turbine;
• circulating the first thermal working fluid from the cryocooler turbine along the first fluid circuit and through the first compressor;
• circulating the first thermal working fluid from the first compressor back to thermal communication with the nuclear reactor core;
• cooling a second thermal working fluid via thermal communication of the second thermal working fluid with a heat exchanger;
• circulating the second thermal working fluid along a second fluid circuit to a cryogenic tank storing propellant;
• cooling the propellant via thermal communication of the second thermal working fluid with the cryogenic tank;
• driving a second compressor of the CFM system via the shaft rotated by the cryocooler turbine;
• circulating the second thermal working fluid from the cryogenic tank along the second fluid circuit and through the second compressor;
• and
• circulating the second thermal working fluid from the second compressor back to thermal communication with the heat exchanger.