Scientists have announced a breakthrough with an ion thruster that could one day take humans to Mars.
It’s called the X3 thruster, a type of ion propulsion known as a Hall thruster. This technology is alluring because it can theoretically achieve higher speeds than conventional chemical propulsion.
In a series of tests at NASA’s Glenn Research Center, researchers said they had now achieved a record power output for a Hall thruster, opening up new avenues of research.
"We have shown that X3 can operate at over 100 kW of power," Alex Gallimore, the project’s lead, told Space.com. "It generated 5.4 Newtons of thrust, which is the highest level of thrust achieved by any plasma thruster to date." (The previous record was 3.3 Newtons.)
Ion thrusters are alluring because they promise high thrust with little fuel input. With little propellant needed, they can theoretically operate for much longer than conventional thrusters, achieving much higher speeds.
We’ve tested out quite a few, too. The longest-running is on NASA’s Dawn spacecraft, which is currently in orbit around the dwarf planet Ceres and launched in 2007. However, that has a thrust of just 90 microNewtons (0.00009 Newtons). Hall thrusters offer a much higher thrust.
Artist's impression of Dawn. NASA/JPL-Caltech
They involve accelerating plasma at extremely high speeds. Electrons are used to bump into atoms, normally of xenon gas. This knocks off more atoms, producing positive ions and thrust. Slowly, over time, this continually increases the speed of a spacecraft.
In theory, a Hall thruster could get a spacecraft up to 40 kilometers (25 miles) per second, eight times faster than a chemical propulsion spacecraft with a top speed of 5 kilometers (3 miles) per second.
Thus, they are hugely promising for spaceflight. If used on manned missions to Mars, for example, the spacecraft could require less propellant and thus more easily be launched into orbit. However, Gallimore noted such an engine would need a lot of power, which is why the X3 thruster is so promising.
By using a bigger thruster, the team said they use multiple channels of plasma rather than just a single channel – called a nested channel. This could allow for these high speeds to be achieved.
This is not the only ion thruster research being conducted. NASA has several other projects on the go, to try and improve methods of spaceflight. Maybe the first humans that go to Mars will have a revolutionary ion thruster to thank.
