A new frontier in space exploration is emerging—not in deep space, but in the very edge of Earth’s atmosphere. Companies and researchers are racing to develop Very Low Earth Orbit (VLEO) satellites, which could revolutionize communications, Earth imaging, and scientific research.
The Promise and Challenge of VLEO
Traditional satellites operate in Low Earth Orbit (LEO) and beyond, at altitudes above 250 miles (400 km). But VLEO, which extends from just below the International Space Station (ISS) down to around 60 miles (100 km), offers a new opportunity. Satellites here can provide higher-resolution imagery, faster communication, and real-time atmospheric data. However, they must contend with the intense drag of Earth’s upper atmosphere, which can quickly pull them out of orbit.
“The atmosphere increases exponentially as you descend,” explains Hugh Lewis, a professor of astronautics at the University of Southampton. “If you don’t counteract drag, your satellite won’t last long.”
To survive in VLEO, new propulsion technologies are needed. One promising approach is Air-Breathing Electric Propulsion (ABEP), which collects air molecules from the atmosphere and converts them into fuel. If successful, this method could allow satellites to maintain orbit indefinitely without the need for onboard fuel.
The Race to Build Air-Breathing Satellites
Several companies are already developing VLEO satellites. Stellar Advanced Concepts, a UK-based firm, received a £390,000 ($510,000) grant to demonstrate ABEP technology by 2027. Similarly, Kreios Space, a Spanish start-up, aims to launch a prototype in 2026 to test how well satellites can sustain themselves at lower altitudes.
In the U.S., the Department of Defense’s Otter program has allocated over $20 million to support air-breathing VLEO satellites. One of the companies benefiting from this funding is Redwire, which is developing an “orbital drone” called SabreSat. Designed with aerodynamic solar panels, SabreSat could stay in VLEO for extended periods.
“The intent is to maintain orbit indefinitely,” says Spence Wise, senior vice president at Redwire.
Meanwhile, Redwire’s European division is working on a separate project called Phantom, part of the European Space Agency’s Skimsat initiative. Set for a 2027-2028 launch, Phantom won’t use air-breathing technology but will instead rely on a streamlined design to minimize drag.
Why VLEO Matters
VLEO satellites offer several advantages over traditional orbiters. Earth observation is a major application, as satellites closer to the planet can capture higher-resolution images for use in military, agriculture, disaster response, and climate research.
“There are lots of applications in maritime tracking, wildfire monitoring, and even atmospheric science,” says Adrián Senar Tejedor, CEO of Kreios Space.
Additionally, VLEO could transform satellite communications. Space-based internet services, like SpaceX’s Starlink, currently use satellites in higher orbits. Lower-altitude satellites could act like cell towers in space, providing faster and more direct connections.
“These lower orbits could enable a direct-to-cell constellation,” explains Tim Farrar, a satellite communications expert.
The Future of VLEO
While VLEO satellites are still in the experimental phase, companies and governments are investing heavily in the technology. If air-breathing propulsion proves viable, these satellites could remain in orbit for years or even decades—ushering in a new era of persistent, low-altitude space observation and communication.
“I expect VLEO to become increasingly popular,” says Alex Newsam of Stellar Advanced Concepts. “Whoever perfects the technology first will have a significant advantage in the market.”
With major players racing to unlock the potential of VLEO, the next chapter of space exploration may not be in deep space—but right above our heads.
