An arcjet rocket or arcjet thruster is a form of electrically powered spacecraft propulsion, in which an electrical discharge (arc) is created in a flow of propellant[1][2] (typically hydrazine or ammonia).
When the energy is available, arcjets are well suited to keeping stations in orbit and can replace monopropellant rockets.
Aerojet MR-510 series arcjet engines are currently used on Lockheed Martin A2100 satellites using hydrazine as a propellant,[3] providing over 585 s average specific impulse at 2 kW.
[4] In Germany, researchers at the University of Stuttgart's Institute of Space Aviation Systems have been working with arcjets for years and have developed various hydrogen-powered arcjet engines capable of power outputs from 1 to 100 kW.
The heated hydrogen reaches exit speeds of 16 kilometres per second (9.9 mi/s).