Radiometric Analysis from the 26-kW Electric Propulsion Space Experiment (ESEX) Flight
Abstract
The United States Air Force Research Laboratory's Electric Propulsion Space Experiment (ESEX) was launched and operated in early 1999 in order to demonstrate the compatibility and readiness of a 30 kW class ammonia arcjet for satellite propulsion applications. As part of this flight, an array of on-board contamination sensors was used to assess the effect of the arcjet and other environments on the spacecraft. The sensors consisted of microbalances to measure material deposition, radiometers to assess material degradation due to thermal radiation, and solar cell segments to investigate solar array degradation. Over eight firings of the ESEX arcjet, (3 minutes, 26 seconds operating time) the radiometer near the thruster, viewing the arcjet plume and body, experienced a change in the thermal properties of its coating (repetitive) Radiometers with no view of the arcjet, or a view of only the plume, show no change. In general, contamination effects are observed only on sensors near the thruster exhaust nozzle, a location unlikely to be used in an operational high-power electric propulsion system. No contamination effects are observed in the backplane of the thruster. For future programs, while engineering measures may be needed for spacecraft equipment in the immediate vicinity of the thruster body, the arcjet environment is generally benign.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 11, 2001
- Accession Number
- ADA405912
Entities
People
- D. R. Bromaghim
- Gg. G. Spanjers
- J. H. Schilling
Organizations
- Air Force Research Laboratory