Parametric design study of ‘‘power stick’’ and its derivatives

The paper addresses some major concerns about the Power Stick concept proposed by Jet Propulsion Laboratory (JPL) personnel, and describes parametric studies of derivative designs to determine to what extent those concerns can be alleviated. The Power Stick and its derivatives are based on the use of the 1‐watt(t) Radioisotope Heater Unit (RHU) to power a thermoelectric multicouple. Our study concludes that: (a) while the RHU has been safety‐qualified as a low‐temperature heater, additional reentry analyses and test would be needed to qualify it as a higher temperature heat source for the Power Stick, (b) even after parametric design optimization, the efficiency of the Power Stick and its derivatives is only 2.2%, and, (c) all generators based on the 1‐watt heat source require a thermoelectric multicouple with a large number of extremely thin legs, of very doubtful fabricability.