Yes, that was my 1st question as well.. If there is no 'oxygen' in Space, where does it get the air from? They want to fly these in a lower Earth orbit.

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By Elizabeth George

A new kind of satellite would use a system to make fuel from the air around it in very low Earth orbit. This would, among other things, make the device lighter and extend its lifespan.
SpaceX launches European satellites
Credits: 123RF

We cannot see them with the naked eye, but there are currently thousands of satellites above our heads. They take photos, provide Internet connections, spot methane leaks, gather various information… It’s starting to get a little crowded up there. This is why scientists are very interested invery low earth orbitOr VLEO. It is a space located between Approximately 100 and 450 km altitude, and much less populated with machines than above. On the other hand, there is still air at this heightwhich means that satellites must be propelled to stay in orbit. Except that once all the fuel is used up, they necessarily have to be replaced.

The solution would therefore be to use a abundant source of energy. And there is one: the air, quite simply. Using it as fuel would make it possible to “reduce the mass of the satellites or allow the difference in mass to be devoted to other aspects of the device. It could also extend the life of the device“, explains Yevgeny Raitses, physicist at the Princeton Plasma Physics Laboratory. But how would this work?

The idea is as follows: a device on board the satellite absorbs air from the atmosphere around it and sends the particles into a ionization chamber which creates plasmacomposed of charged particles. The latter are accelerated then expelled outside, propelling the machine. This is not the first time that we have talked about what we call a aerobic plasma engine. The laboratory’s mission is precisely to create a prototype that will serve as proof of concept. However, there are still points to be resolved.