Planetary mission applications for space storable propulsion

This paper presents the results of a study to compare space-storable with earth-storable spacecraft propulsion systems, space-storable with solid kick stages, and several space-storable development options on the basis of benefits received for cost expenditures required. The results show that, for a launch vehicle with performance less than that of Shuttle/Centaur, space-storable spacecraft propulsion offers an incremental benefit/cost ratio between 1.0 and 5.5 when compared to earth-storable systems for three of the four missions considered. In the case of VOIR 83, positive benefits were apparent only for a specific launch vehicle-spacecraft propulsion combination. A space-storable propulsion system operating at thrust of 600 lbf, 355 units of specific impulse, and with blowdown pressurization, represents the best choice for the JO 81 mission on a Titan/Centaur if only spacecraft propulsion modifications are considered. For still higher performance, a new solid-propellant kick stage with space-storable spacecraft propulsion is preferred over a system which uses space-storable propellants for both the kick stage and the spacecraft system.