The European counterpart to NASA, the ESA, has been working on specialized thrusters for about a decade now. These would collect and store air from the upper layers of an atmosphere, and then shoot them back out as a propellant. This could totally change how many of our satellites work, and how we use them.
Even in the upper layers of the atmosphere, there is enough air to cause atmospheric drag. Over time, this slows down just about anything in orbit and will ultimately cause to crash back down. Thrusters can help, but they run on chemical fuel and need to be topped up every so often. This causes a lot of problems and requires many, many satellite launches as most of the objects in orbit cannot be filled back up once launched. This means that with the exception of larger structures like the International Space Station, everything in orbit around Earth has a finite lifespan. But that could change.
“This result means air-breathing electric propulsion is no longer simply a theory but a tangible, working concept, ready to be developed, to serve one day as the basis of a new class of missions,” one ESA scientists, Louis Walpot says.
Trying to find a way to gather enough of the scant air to make these engines work was a challenge. The basic idea isn’t too far off from the ion drive that many real-world spacecraft already use, but such a slow, steady speed increase isn’t quite enough for satellites dealing with orbital drag. But, with some tooling, the team managed to get a working prototype. First with Xenon gas, which has the best thrust potential of the readily usable gases on Earth. Then the team tried it with a nitrogen-oxygen mixture, then, finally, with the types of lightweight, scant gases that would found floating miles above the surface.
It will be some time before the system is ready for launch, but it offers lots of new possibilities — including permanent or near-permanent orbiters around other planets in the solar system. This could give us constant updates on all kinds of space weather and other phenomena that we’d never have been able to take advantage of before.
Now, to be clear, this isn’t generating power from nothing. The engines still require electricity, but generally, solar panels can collect enough juice to keep these systems working for, potentially, years and years on end. That’s pretty awesome.
