Colloid Microthruster Experiment.
Abstract
A colloid microthruster system was developed. It consists of a thruster, neutralizer, zero-gravity propellant feed system, and power and signal conditioning unit. Operating directly from 5 watts spacecraft input power, using external commands in the form of relay contact closures, it provides either 4 or 8 micropounds of thrust. The 7-pound system contains 0.5 pound of 19.3 percent by weight sodiumiodide in glycerol propellant. A metal ball seat valve protects propellant from atmospheric gases during storage periods, and provides on-off flow control during operation. System turn-on and turn-off response is limited by the fluid thermal actuators for the valve once the thruster has been filled with propellant after initial valve opening. Operation at 950-second specific impulse was demonstrated for the 8-micropound thrust level. System evaluation included thruster performance mapping, environmental test, electromagnetic compatibility testing, and thermal analysis. The system was operated for over 1750 hours during life test. Neutralizer operation was interrupted after 950 hours because of electron leakage through some insulator holes. The test was terminated upon loss of expulsion pressure in the feed system. Pulsed single-needle colloid operation demonstrated 60 percent efficiency at an estimated 1000-second specific impulse for a 20 percent duty cycle and a repetition rate of 60 pulses per minute. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1970
- Accession Number
- AD0873999
Entities
People
- Haywood Shelton
- John C. Beynon
- Robert F. Kemp
- Sidney Zafran
Organizations
- TRW Inc.