A doctoral candidate at the University of Sydney designed an ion thruster — a system that propels spacecraft by expelling ions to create thrust — that destroys the fuel efficiency world record set by NASA’s space propulsion system.
NASA ground tested its High Power Electric Propulsion (or HiPEP) ion thruster in 2003 and set the fuel efficiency record of 9,000 seconds (give or take 200 seconds) of specific impulse, which is a measure of thrust or efficiency.
Patrick Neumann, the Australian doctoral student at the University of Sydney, recently smashed that record by creating an ion thruster with a fuel efficiency record of 14,690 seconds (give or take 2,000 seconds), the University of Sydney’s student paper the Honi Soit first reported. Even by conservative estimates, Neumann’s ion thruster (dubbed the Neumann drive) blows NASA’s system out of the water.
NASA’s HiPEP was designed for the Jupiter Icy Moons Orbiter, a spacecraft meant to explore Jupiter’s moons, which was canceled in 2005. The main target at the time was to reach Europa, the sixth-closest moon of Jupiter, which could be habitable for life. (The European Space Agency is planning to launch its Jupiter Icy Moons Explorer in 2022, which would get it there by 2033).
The Neumann Drive could be ideal for space travel because of its improved efficiency, making it better for long trips (say, to an icy moon near Jupiter). Neumann himself suggested that his ion thruster could get to “Mars and back on a tank of fuel.”
Unlike the HiPEP, which can only run on xenon gas, the Neumann Drive can run on a variety of metals. This means the system could recycle “space junk” or use discarded metals from satellites and other debris to continue running.
So far, the Neumann Drive runs best on magnesium, but tests have been performed on vanadium, titanium and carbon. It should be able to run on anything that can conduct electricity.
Although the Neumann Drive may be better for the long haul, the HiPEP is better when it comes to acceleration. On his website, Neumann notes that his ion thruster is not good at throwing a lot of power over time, meaning it would be used to keep satellites in their orbit or send probes into space rather than launch a spacecraft.
The Neumann Drive runs based on a reaction between electricity and metal. Electric arcs strike magnesium (or whatever other chosen fuel works) causing ions to spray. A magnetic nozzle focuses the ions to create thrust.
Being fuel efficient is cost effective, Neumann notes on his website. To send a kilo of anything into space, it can cost anywhere between $US10,000 to $US50,000. An International Space Station (ISS) requires seven tonnes of fuel to keep course in space, bringing that cost up to a minimum of $US70 million. “A more efficient engine would require less fuel needing to be brought up — which would result in a dramatic reduction in costs,” Neumann writes on his website.
Neumann has lodged a patent and is currently securing funding for the next stage of research and development.