In the future, spacecraft could be propelled by air. It’s a prediction that sounds like a child’s wild imaginings, but the idea could become reality if research by scientists at the UK’s University of Surrey is successful.
Funded to the tune of £250,000 from the UK Space Agency, the new system proposed by the university’s space centre relies on the development of a new type of spacecraft that can suck in air from Earth’s atmosphere and treat it in a specialized ionization chamber. The air particles, zapped with energy, are transformed into plasma, which can then be used as a propellant. Removing the need to carry fuel on board, the system is essentially self-sustaining, meaning that mission lifetimes for satellites and other craft in orbit, need not be dictated by fuel capacity.
Air-breathing spacecraft
The so-called “air-breathing electric propulsion” (ABEP) spacecraft will operate in very low Earth orbit (VLEO) between about 150 km and 402 km up (95 and 250 miles). In fact, the system relies on the very thin air in low orbit.
We’ve been developing a cathode, or neutraliser, to work in electrostatic thrusters operating in the thin air found in ultra-low Earth orbit.
Mansur Tisaev, postgraduate research student at the University of Surrey
“By collecting and compressing the gases at that altitude, we can create a propellant flow that is ionized and accelerated using combinations of electric and magnetic fields, harnessing electrical power from solar panels,” explained Mansur Tisaev, a postgraduate research student at the university.
Advantages and challenges of very low orbit
Operating satellites and other craft in very low Earth orbit has potential advantages, the team believes. As well as being a relatively uncongested part of space, opportunities for close quarters views of our planet, climate monitoring, and improved communications could be unlocked by the innovation.
VLEO offers the chance of “Earth observation at much higher resolutions than offered at present,” Dr Andrea Lucca Fabris, Senior Lecturer in Electric Propulsion at the university, said. Not only that, but “It could also mean faster telecommunications, and it opens the door to new scientific discoveries about conditions in the ionosphere, which could help develop more accurate atmospheric models.”
Operating in VLEO conditions presents difficulties for today’s satellites, due to the increased atmospheric drag at low altitude, but, if the Surrey researchers can prove their minimal propulsion ABEP technology, then potentially infinite propulsion satellites could be coming to a Very Low Earth Orbit near you.
