NASA’s ion thruster breaks power & propulsion records

NASA’s newest ion thruster has broken previous records of generating maximum power and propulsion in its latest test, suggesting the technology may become the future of deep space exploration.

The X3 thruster is being developed by researchers at the University of Michigan in collaboration with the US Air Force and NASA. The group has been working on the technology since 2009. They first developed a two-channel thruster, the X2, before the more powerful X3 was created.

The X3 thruster team said it broke records of generating maximum power output during recent testing at the Genn Research Center of NASA in Ohio. Project lead Alec Gallimore said the thruster generated 5.4 N of thrust, the highest value of thrust recorded using a plasma thruster.  

"We have shown that X3 can operate at over 100 kW of power," Gallimore told Space.com. "It operated at a huge range of power from 5 kW to 102 kW, with electrical current of up to 260 amperes. It generated 5.4 Newtons of thrust, which is the highest level of thrust achieved by any plasma thruster to date."

The X3 thruster is a Hall thruster, a type of system that uses a stream of ions to propel a spacecraft and expels plasma (a cloud of charged particles) to generate thrust. This allows for greater speeds than a traditional chemical propulsion rocket, and greater efficiency, as they require less propellant and can go about 10 times further on the same amount of fuel.

“You can think of electric propulsion as having 10 times the miles per gallon compared to chemical propulsion,” Gallimore said.

A chemical rocket has a maximum speed of 5km per second, and Hall thrusters can reach up to 40km per second.

This difference is particularly important when it comes to the future of long-distance space travel. According to the project’s team leaders, the ion propulsion technology could help blast humans to Mars within 20 years.

Ion thrusters have to operate for a long time to make a spacecraft reach high speeds.

“What we would need for human exploration is a system that can process something like 500,000 watts (500 kW), or even a million watts or more,” Gallimore said.

The X3 team are making the thruster bigger and creating a design that has multiple plasma channels so as to make the X3 more compact.

“We figured out that instead of having one channel of plasma, where the plasma generated is exhausted from the thruster and produces thrust, we would have multiple channels in the same thruster,” Gallimore said. “We call it a nested channel.”

The X3 faces a greater challenge next year, when it will be tested to see if it can operate at full power for 100 hours.