Analysis of Possible Stratagems for Enhancing the EOM Power of RTGs for the CRAF Mission

摘要

The upcoming CRAF and Cassini missions originally were each baselined to use two RTGs identical to those flown on the recent Galileo and Ulysses missions. Fairchild analyses showed that two such RTGs could meet JPL's originally specified power demands. However, JPL subsequently raised both the power demand profile and the duration for both missions, to the point where two standard RTGs could no longer provide the desired power margin. Each mission can be satisfied by adding a third RTG, and in the case of the Cassini mission the use of three RTGs appears to be unavoidable. In the case of the CRAF mission, there appeared to be a possibility that modest modifications of the RTGs' design and/or operating scheme may meet the missions' power demand (including specified contingency reserves) without the addition of a third RTG. The potential saving in cost and schedule pressure prompted Fairchild to undertake a study of various obvious and not-so-obvious power-enhancing stratagems to determine whether they could reach the desired goals, either singly or in combination. The present paper describes the various stratagems investigated by Fairchild, and discusses their drawbacks and their effectiveness.