This study has been made to assess the needs, potential benefits and the applicability of early (circa year 2000) Nuclear Electric Propulsion (NEP) technology in conducting NASA science missions. The study goals are: to obtain the performance characteristics of near term NEP technologies; to measure the performance potential of NEP for important OSSA missions; to compare NEP performance with that of conventional chemical propulsion; to identify key NEP system requirements; to clarify and depict the degree of importance NEP might have in advancing NASA space science goals; and to disseminate the results in a format useful to both NEP users and technology developers. This is a mission performance study and precludes investigations of multitudes of new mission operation and systems design issues attendant in a NEP flight.

A phase 2 study has been initiated to investigate surfactant- assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the fourth quarter of work. The major accomplishments were (1) Completion of coal liquefaction autoclave reactor runs and related analysis with Illinois {number_sign}6 coal with time as a variable at 375{degree}C, and pressures of 1800 psig; (2) an investigation into the mechanism of the effect that the lignosulfonate surfactant has in enhancing liquefaction yields; and (3) completion of a bench-scale test with the surfactant in the continuous flow Catalytic Two Stage Liquefaction Process (CTSL) reactor at HRI.