Ion thruster

Of all the electric thrusters, ion engines have been the most seriously considered commercially and academically. Ion engines use accelerated beams of ions for propulsion.

Ion engines are best used for missions requiring very high delta-V's (the overall change in velocity, taken as a single value), interplanetary missions, for example. This is because the more performance required of the propulsion system, the faster a high efficiency system like an ion engine will pay off.

NASA has developed an ion engine called NSTAR for use in their interplanetary missions. This engine was tested in the highly successfull space probe Deep Space 1. Hughes has developed the XIPS ([[Xenon Ion Propulsion System]]) for performing stationkeeping on geosynchronous satellites.