Electrostatic ion thruster

The gridded ion thruster is a common design for ion thrusters, a highly efficient low-thrust spacecraft propulsion running on electrical power. These designs use high-voltage grid electrodes to accelerate ions with electrostatic forces.

The ion engine was first demonstrated by German-born NASA scientist Ernst Stuhlinger, and developed in practical form by Harold R. Kaufman at NASA Lewis (now Glenn) Research Center from 1957 to the early 1960s.

The use of ion propulsion systems were first demonstrated in space by the NASA Lewis "Space Electric Rocket Test" (SERT) I and II. These thrusters used mercury as the reaction mass. The first was SERT-1, launched July 20, 1964, which successfully proved that the technology operated as predicted in space. The second test, SERT-II, launched on February 3, 1970, verified the operation of two mercury ion engines for thousands of running hours. Despite the demonstration in the 1960s and 70s, though, they were rarely used before the late 1990s.

NASA Glenn continued to develop electrostatic gridded ion thrusters through the 1980s, developing the NASA Solar Technology Application Readiness (NSTAR) engine, that was used successfully on the Deep Space 1 probe, the first mission to fly an interplanetary trajectory using electric propulsion as the primary propulsion. It is currently flying the Dawn asteroid mission. Hughes Aircraft Company (now L-3 ETI) has developed the XIPS (Xenon Ion Propulsion System) for performing station keeping on its geosynchronous satellites (more than 100 engines flying). NASA is currently working on a 20-50 kW electrostatic ion thruster called HiPEP which will have higher efficiency, specific impulse, and a longer lifetime than NSTAR. Aerojet has recently completed testing of a prototype NEXT ion thruster. At Giessen University and EADS the radio-frequency ion thrusters RIT were developed starting in the 1970s. RIT-10 engines are flying on ARTEMIS. Qinetiq (UK) has developed the T5 and T6 engines (Kaufman type), flying the GOCE mission (T5) and is baselined for BepiColombo mission (T6). In Japan, microwave engines µ10 flew on the Hayabusa mission.

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