Radioisotope Thermoelectric Generators (RTGs) and Heater Units (RHUs) Based on Americium-241 for Science and Exploration

摘要

Radioisotope thermoelectric generators (RTG) and heater units (RHU) are under development by the European Space Agency (ESA). Aimed at enabling or significantly enhancing challenging space, planetary science and exploration missions, this programme relies on the cost-effective production of americium-241 as the radiogenic heat source and an iterative engineering approach to developing the systems which include isotope containment architectures, and in the case of RTG systems, thermoelectric generators. The RTG and RHU containment systems rely on the use of inner platinum-rhodium alloy cladding, insulation layers and carbon-carbon composite outer aeroshells. The RTG heat source configuration is designed to deliver 200 W. The modularity of the RTG design allows the 200 W heat source to build scalable RTG systems with electrical power outputs ranging between 10 W and 50 W per RTG unit. RHUs are being developed for thermal management applications. These are designed to deliver 3 W of thermal power per unit. This paper describes the most recent updates in system designs and provides the results of recent laboratory prototype test campaigns.