Compact, efficient thermoelectric module for a space reactor

The thermoelectric module for the Space Reactor (SPAR) program is a compact annular unit that provides high heat fluxes with a minimum of heat losses. All interfaces are fully bonded to minimize extraneous temperature drops. In order to reduce stresses within the module, the thermoelectric material is circumferentially segmented and a radial stress relief member is provided. An enhanced silicon-germanium material allows high temperature operation and provides a high figure-of-merit. By using a titanium silicate sublimation coating, the hot junction temperature can be increased further. Thus, a module with reasonably high thermoelectric efficiency, high reliability, and low weight is produced. Since 66 of these thermoelectric ring modules comprise a generator, and 90 generators make up the SPAR conversion system, adequate redundancy is also provided