U-M researchers develop technology to make smaller, more efficient 'H9 MUSCLE' thrusters for satellites

A team of University of Michigan (U-M) researchers is experimenting with thruster technology that could potentially power a crewed mission to Mars.

According to a press release from the University of Michigan, researchers have found that smaller Hall thrusters can generate more thrust than previously thought, making them viable solutions for interplanetary missions. 

“People had previously thought that you could only push a certain amount of current through a thruster area, which in turn translates directly into how much force or thrust you can generate per unit area,” said Benjamin Jorns, U-M associate professor of aerospace engineering who led the new Hall thruster study, according to the press release.

Jorns’ team was able to run their thruster, named the H9 MUSCLE, up to 45 kilowatts using krypton, a lighter gas. The thruster was able to achieve a maximum thrust of about 1.8 Newtons, an overall efficiency of 51%, which is on par with much larger 100-kilowatt-class X3 Hall thrusters. 

“We named our thruster the H9 MUSCLE because essentially, we took the H9 thruster and made a muscle car out of it by turning it up to 11—really up to a hundred, if we’re going by accurate scaling,” said Leanne Su, a Ph.D. student in aerospace engineering who will present the study, according to the press release. 

Nested Hall thrusters, like the X3, are usually considered for cargo transports since they are much larger and heavier than other solutions which makes it difficult for them to transport humans. With these new developments, however, ordinary Hall thrusters may be considered for crewed journeys. 

During testing, the thruster would get extremely hot, but the team was able to cool it with water. According to Jorns, a space-worthy cooling solution will need to be implemented if the Hall thrusters are to run at such high output. 

The team will continue to pursue solutions to the cooling issue while also continuing their work to develop both Hall thrusters and magnetoplasmadynamic thrusters.