Bombardment thruster investigations at the Lewis Research Center.

Abstract

The current s t a t u s of various research programs on mercury electron-bombardment thrusters i s reviewed. Future thruster ,requirements as predicted from mission analysis are b r i e f l y discussed t o establish the relationship with present programs. Thrusters ranging i n size from 5 t o 150 cm diameter are described. These thrusters have possible near t o far term applications extending from station keeping t o primary propulsion, respectively. power-to-thruSt r a t i o of 220 kW/lb; the 15 cm diame t e r SERT I1 thruster; and, a 30 cm thruster designed t o produce a 1.5 ampere beam at 2,700 sec sp6cific impulse.components are reported i n the context of the various thruster programs. These include glass-coated, single acceleratdr grids that have a c c m a t e d more than 500 hr operating time; higbcurrent h o l l m cathodes of 10 amperes emission; and, a minim-B discharge chamber. Included i s a 5 cm thruster having a Research a c t i v i t i e s on thruster