Atmosphere-breathing electric propulsion

[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.

This assumption, however, is not applicable to ion thrusters operating in low Earth orbit, where ambient gas enters the ionization chamber at high velocities.

This adaptation has been significant for the theoretical modeling of ion propulsion systems, particularly those that operate in the rarefied conditions of low Earth orbit.

By accounting for the high-velocity ambient gas that enters the ionization chamber in low Earth orbit, the modified law allows for more accurate theoretical modeling.

Such a device has the main advantage of no components in direct contact with the plasma, this minimizes the performance degradation over time due to erosion from aggressive propellants, such as atomic oxygen in VLEO, and does not require a neutralizer.

With fully diffuse reflection properties, efficiencies are generally lower, but with a trapping mechanism the pressure distribution in front of the thruster can be enhanced as well.

This breakthrough enables the propulsion system to generate enough thrust to overcome atmospheric drag in very low Earth orbit, allowing sustainable spacecraft operation at altitudes below 200 km.