Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

Abstract

This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated space power generators. Those generators employed general purpose heat source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC's revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator's 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator's performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack.