Atmosphere-breathing plasma engine concept could sustain satellites in orbit

Researchers at the University of Stuttgart have developed a plasma engine concept that could allow satellites to remain in Very Low Earth Orbit (VLEO) indefinitely by using atmospheric gases as fuel.

Developed by Francesco Romano as part of PhD research, the technology falls under atmosphere-breathing electric propulsion (ABEP). The system uses an intake to collect thin atmospheric molecules, converts them into plasma, and expels them to generate thrust. This approach could eliminate the need for satellites to carry heavy, expensive propellants like xenon.

Operating in VLEO (100–450 km) offers advantages such as higher-resolution Earth observation and lower power requirements for communications, but atmospheric drag typically forces satellites to descend. The proposed engine uses a radio-frequency helicon-based plasma thruster with a parabolic intake. Laboratory and computer modeling indicate high efficiency, with one tested intake variant capturing approximately 94.3% of particles.

A significant engineering hurdle remains the presence of atomic oxygen in the upper atmosphere, which is highly oxidative and can corrode engine components like electrodes and acceleration grids.