Atmosphere-breathing electric propulsion

Atmosphere-breathing electric propulsion, or air-breathing electric propulsion, shortly ABEP,^[1] is a propulsion technology for spacecraft, which could allow thrust generation in low orbits without the need of on-board propellant, by using residual gases in the atmosphere as propellant. Atmosphere-breathing electric propulsion could make a new class of long-lived, low-orbiting missions feasible.

The concept is currently being investigated by the European Space Agency (ESA) ^[2] and the EU-funded DISCOVERER project.^[3] Current state-of-the-art conventional electric thrusters cannot maintain flight at low altitudes for any times longer than about 2 years,^[4] because of the limitation in propellant storage and in the amount of thrust generated, which force the spacecraft's orbit to decay. The ESA officially announced the first successful RAM-EP prototype on-ground demonstration in March 2018.^[5]