VLEO: The new battleground in the space tech race – Here’s what it means

Professor Sven Bilén from Penn State says satellites in VLEO send faster data. They also capture sharper images and reduce orbit congestion. But keeping satellites in this region is not easy.

Bilén leads a project funded by DARPA’s Charge Harmony programme. His team at Penn State works alongside Georgia Tech researchers. Together, they are developing a new thruster to help satellites remain in VLEO, according to a report by EurekAlert.

Solving Big Challenges in Tiny Orbits
Satellites in VLEO struggle with aerodynamic drag. This slows them down and pulls them out of orbit. They need constant thrust to stay in place.

Traditional fuels can’t last long at such altitudes. That’s where “air-breathing” electric thrusters come in. These systems collect thin air around them to use as fuel.

Another problem is the lack of power. Sunlight gets blocked by Earth during parts of the orbit. This limits the energy available for propulsion.

Bilén’s team is working to fix both problems. Their solution uses rarefied air and a self-neutralising system. The thruster design also cuts power demands.

A Closer Look at the AMPT Thruster
The team’s thruster is called the “air-breathing microwave plasma thruster” (AMPT). It gathers air, heats it using microwaves and pushes it out for thrust. The expelled gas is self-neutralised, avoiding complex equipment.

Other systems need external devices to handle charged gases. AMPT doesn’t need that. It also avoids using a cathode, which wears down in oxygen-rich air.

This makes the AMPT more suitable for long missions in VLEO. It runs on a thermal heating process instead of electrical discharge.

Early Success and What Comes Next
In the first year, the team tested the AMPT in labs. They used vacuum chambers at Penn State and Georgia Tech. The thruster produced more thrust per kilowatt than usual systems. In some cases, it performed hundreds of times better.

Now, DARPA has asked the team to scale it down. The smaller thruster will fit into compact satellite platforms. A future satellite using this tech will orbit lower than ever before.

The team is also planning a full satellite design. This will support the AMPT and test real-world missions.

Exploring a New Layer of Orbit
For Bilén, the thrill lies in new possibilities. This tech may create the lowest orbiting satellite ever made. At the same time, it could be the highest-flying air-breather.

The edge of Earth’s atmosphere could soon become very busy. And with AMPT, satellites may stay there longer than ever.