electron bombardment thruster
An electron bombardment thruster, also known as an electrostatic ion thruster, is one of the most promising forms of electric space propulsion and one of only two forms of ion propulsion currently employed aboard spacecraft, the other being the Hall effect thruster.
How it works
Research and developmentEarly research on this type of engine was carried out in the 1960s and 1970s used mercury or cesium gas as the propellant; an important example involved the SERT (Space Electric Rocket Test) spacecraft. However, it was found that the ions of these elements tended to adhere to and erode the grids. Further work showed that ions of the heavy inert gas xenon suffered less from this problem, and resulted in good engine efficiency with minimum erosion of the ion optics. Xenon has thus become the propellant of choice in all modern ion propulsion systems, both of the electron bombardment and Hall effect variety.
The two most significant operational forms of electron bombardment thruster are the NSTAR, developed by NASA, and used aboard Deep Space 1, and XIPS (xenon-ion propulsion system), developed by Hughes (now part of Boeing), and used for station-keeping on some geosynchronous satellites. NASA is also developing a 20–50 kW electron bombardment thruster, called HiPEP, which will have higher efficiency, specific impulse, and lifetime than NSTAR.
Related categories ADVANCED PROPULSION CONCEPTS
ROCKET ENGINE TYPES
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