Kreios Space

Kreios Space is a Vigo, Spain-based propulsion startup founded in 2021 developing Air-Breathing Electric Propulsion (ABEP) systems that enable satellites to operate in Very Low Earth Orbit (VLEO) altitudes of 150-250 km — altitudes that offer dramatically superior Earth observation resolution (sub-10 cm potential) and lower signal latency for communications, but where atmospheric drag normally causes rapid orbital decay within days or weeks.

The ABEP system operates without onboard propellant: an intake scoop collects ambient molecular oxygen and nitrogen from the tenuous upper atmosphere, compresses and ionizes the collected gas into plasma using an RF or microwave discharge, and accelerates the plasma through an ion thruster to produce thrust that exactly counteracts atmospheric drag — enabling indefinite station-keeping without consumable propellants. This propellant-free approach theoretically enables multi-year VLEO missions that are impossible with conventional chemical or ion propulsion limited by propellant mass.

The core engineering challenges Kreios is addressing include intake geometry optimization to maximize neutral gas collection efficiency at hypersonic flow speeds, plasma generation from variable-composition mixed-species gas (unlike pure xenon or krypton used in conventional ion thrusters), and thruster efficiency scaling to the millinewton thrust levels needed for drag compensation at VLEO. Kreios has received ESA funding through the Basic Activities and Discovery Elements programs, positioning the technology within the European VLEO Earth observation roadmap.

Competing ABEP approaches are under development at the University of Tokyo (RAM-EP), SITAEL in Italy, and the European Space Agency's Advanced Concepts Laboratory, making VLEO propulsion one of the more competitive emerging propulsion research niches.