Nuclear Gas Turbine Propulsion System for a Long Endurance Titan Aerial Vehicle

An innovative propulsion system concept that enables powered flight on Saturn’s largest moon, Titan, is discussed. This propulsion system concept uses waste heat from a NASA Multi-Mission Radioisotopic Thermoelectric Generator (MMRTG) to power a gas turbine engine. The propulsion system captures MMRTG waste heat by utilizing the in-situ resources of Titan’s cold dense nitrogen atmosphere as a working fluid, passed through a heat exchanger. The heated gas is then run through a turbine to extract electrical power significantly greater than that available from the MMRTG’s thermoelectric effect. In addition to analysis, an experimental system was constructed to validate the feasibility of the proposed concept. This investigation compares the results obtained with this experimental system to analytic predictions. Experimental system performance exceeding 500 watts of measured power output was achieved. This propulsive performance enables consideration of a robotic vertical takeoff and landing vehicle with an altitude ceiling of 15 km, range of 50 km, endurance of 3-4 months, payload capacity of 25 kg, and a gross mass of 400 kg as a future Titan aerial platform.