Development of small radioisotope heaters.
A design study was conducted to (1) determine potential applications of small (1 to 50 watt) radioisotope heaters in manned spacecraft thermal control and life support systems and (2) develop designs for an optimum group of heaters to fulfill a maximum number of applications with mission times from 14 days to 5 years. Thirty-seven potential application areas were identified requiring up to 300 heaters ranging in size from less than 1 to over 100 watts. Safety and design criteria were selected and reference heater designs developed. Optimization analysis indicated that two heater sizes, 10- and 50-w, and two fuels, promethia and plutonia, would most efficiently meet the majority of identified applications.