Mission Capabilities of Ion Engines Using SNAP-8 Power Supplies

Mission performance capabilities of ion engines powered by the 30 kw and 60 kw SNAP-8 power supplies are compared for the following missions: a 24-hr equatorial satellite, a 100 n mi lunar satellite, a 500 n mi Mars satellite, a Mercury probe, and an out-of-the-ecliptic probe. The capabilities of arc- jet engines and chemical engines for the same missions are compared with those of the ion engines. The majority of the comparisons are for 8500-lb spacecraft which are boosted into a 300 n mi orbit by the Atlas-Centaur. Variations in initial orbit altitude, the use of actual launch dates rather than dates based on simplifying assumptions, and the combined use of chemical and electrical propulsion systems were also evaluated in terms of their effect on mission performance.