NASA has activated Psyche's electric Hall thrusters as it softly approaches a metal-rich asteroid in the main asteroid belt beyond Mars.
6 months after launching on October 13, 2023, on a standard SpaceX rocket, the agency claims Psyche is in “full cruise” mode.
While traveling, NASA tested laser-based deep space communications with Psyche. NASA's first communications laser was fired from nearly 10 million miles away.
NASA will receive data from its two-year orbit around the Psyche asteroid, which it will reach by 2029. Scientists believe Psyche is a planetesimal, or planet precursor.
Ion propulsion is new and old for NASA. Since 1964, when the CIA tested its first ion thruster, it has worked on the technology.
They generate thrust by energizing xenon particles and propelling them out of the thruster without moving parts. This NASA ion propulsion document (PDF) explains them.
Psyche uses magnetic Hall thrusters, one of many ion propulsion methods. Psyche's Spacecraft Chief Engineer described the distinctions between those and other ion thrusters, arc jets, and microwave thrusters in 2018.
NASA first employed ion propulsion for Deep Space 1, a 1998 mission to test “various advanced technologies for future interplanetary missions.”
Dawn was NASA's “first exclusively science-focused” mission to use ion thrusters in 2007, flying until its orientation thrusters ran out of hydrazine. It needed those to spin itself around and communicate with NASA.
Though not powerful enough to launch a rocket from Earth, ion propulsion can attain great speeds over time. NASA estimates that Psyche is flying at 23 mph (84,000mph) and will reach 124,000mph.
Without moving parts, thrusters like Psyche's are durable and require less fuel, making them lightweight and suitable for smaller spacecraft. Additionally, they look nice when on.