[en] During recent years, Battelle has been engaged in research on impact members of radioisotope thermal generators (RTGs) for space use. Emphasis in the research to date has been on developing a materials technology. This effort has now reached a stage where consideration can be given to engineering measures for assessing and upgrading the performance of impact members in RTGs of current interest, including particularly General Electric Company's Multi-Hundred Watt (MHW) RTG and the General Purpose Heat Source (GPHS) being developed by Los Alamos Scientific Laboratory. New research goals have been set accordingly. The purpose of the report is to present these goals, give the rationale for them, and indicate the research approaches for meeting them