Solar Thermionic Space Power Technology Testing: A Historical Perspective

This paper provides a brief overview of both the past and recent efforts aimed at the development and testing of solar thermionic space power systems. Recently, the Air Force has been investigating the feasibility of developing a thermionic generator, heated with a large inflatable solar concentrator, for orbital space power missions with electrical power requirements that exceed 50 kWe. This concept analysis follows a similar study by the NASA Jet Propulsion Laboratory in the 1960’s where the objective was a 500 We power generator for interplanetary probes. Details of the potential missions, system designs, and power specifications, as well as results of ground tests and demonstrations are detailed and compared for each era.