During the Electric Propulsion Space Experiment (ESEX) mission, eight firings of the 26 kW ammonia arcjet were performed. Data from on-board systems, GPS, and radar ranging taken during these firings are used in this paper to determine thruster performance. The on-board Servo Accelerometer Assembly (SAA) measured spacecraft acceleration continually at 10 Hz. Although the design prohibited precise acceleration measurement in the range nominally expected during the firings, estimates of acceleration were obtained. The uncertainties of the acceleration estimates are on the order of 5% of nominal due primarily to the discretization error of the A/D converter. Mean performance figures are calculated based on acceleration and other on-board measurements. The final estimates of specific impulse and thrust efficiency are 787.0 +/- 49.8 seconds and 0.284 +/- 0.029, respectively.
Preliminary Orbital Performance Analysis of the Air Force Electric Propulsion Space Experiment (ESEX) Ammonia Arcjet
1999
10 pages
Report
No indication
English
Electric & Ion Propulsion , Arc jet engines , Image processing , Flight testing , Experimental data , Space environments , Accelerometers , Emission spectra , Optical detectors , Analog to digital converters , Thrusters , Servomechanisms , Specific impulse , Saa(Servo accelerometer assembly) , Esex(Electric propulsion space experiment)