World's First Air-Breathing Satellite Thruster Set for Test, Unlocking Very Low Earth Orbit

The popular conception of spaceflight assumes that once a satellite reaches orbit, it floats effortlessly in a perfect vacuum. The reality is far more abrasive. In low Earth orbit (LEO), spacecraft constantly wade through a tenuous but persistent thermosphere, experiencing aerodynamic drag that steadily saps their momentum.[1]

To avoid falling back to Earth, traditional satellites must carry heavy tanks of chemical propellant or xenon gas to periodically boost their altitude. This creates a hard physical limit on a mission's lifespan: the moment a spacecraft exhausts its onboard fuel reserves, its operational life is effectively over, and gravity reclaims it.[2][3]

A new orbital demonstration aims to bypass that limitation entirely. Spanish aerospace startup Kreios Space has contracted Lithuanian manufacturer Kongsberg NanoAvionics to supply the satellite bus for the world's first commercial test of an Air-Breathing Electric Propulsion (ABEP) system. The mission is designed to prove that a spacecraft can scoop up the very atmosphere that causes drag and use it as infinite fuel.[1][4]

The 200-kilogram demonstration satellite will be built around a modified NanoAvionics MP42 microsatellite bus. According to the flight plan, the spacecraft will deploy at an altitude between 300 and 350 kilometers and slowly drift downward, firing its engine at various altitudes to study atmospheric conditions in the largely unexploited Very Low Earth Orbit (VLEO) regime.[1][4]

The mechanics of the ABEP system represent a significant departure from standard electric thrusters. Instead of drawing from an internal pressurized tank, the satellite features a specialized forward-facing intake designed to capture residual oxygen and nitrogen molecules from the upper atmosphere.[1][2]

Once collected, these trace gases are channeled into a helicon plasma thruster, where they are ionized and accelerated out the rear of the spacecraft using a solenoidal magnetic field. By generating continuous thrust from the ambient environment, the system theoretically allows a satellite to maintain an altitude of 150 to 300 kilometers indefinitely without the mass penalty of carrying its own propellant.[1][4]

The commercial stakes for unlocking VLEO are substantial. Operating closer to the planet's surface provides unmatched advantages for Earth observation, allowing relatively small, inexpensive optical payloads to capture sub-meter resolution imagery that would normally require massive telescope mirrors at higher altitudes.[1]

For telecommunications, flying below 300 kilometers dramatically reduces signal propagation latency and improves link budgets. It also offers a pristine operating environment. Traditional LEO has become increasingly congested, with over 10,900 working satellites currently in orbit—the vast majority belonging to broadband mega-constellations. VLEO, by contrast, is virtually empty.[1][4]

Furthermore, VLEO is naturally self-cleaning. If a satellite fails at 200 kilometers, atmospheric drag will pull it into a fiery reentry within weeks, entirely sidestepping the space debris crisis that threatens higher orbital lanes.[4]

Despite the marketing promises of "sustained operations" and multi-year mission lifespans, the upcoming demonstration is fundamentally a sprint rather than a marathon. Because the off-the-shelf MP42 bus is not aerodynamically optimized for the severe drag of VLEO, the initial test flight is only expected to survive for six to ten months before succumbing to orbital decay.[1][4]

Operating in the upper thermosphere is brutally difficult. Spacecraft face severe aerodynamic torques that can cause violent tumbling, requiring heavy modifications to attitude control systems and mass properties just to keep the intake pointed forward.[2][4]

Kreios Space intends to use the telemetry gathered during this short-lived descent to design a fully custom, drag-compensated satellite bus by 2029. If the air-breathing thruster proves viable in actual flight conditions, it could fundamentally alter satellite economics, trading the cost of heavy fuel tanks for the engineering challenge of flying aerodynamically in space.[1][4]