NASA has resolved a propulsion issue on its Psyche asteroid mission by switching to a backup xenon propellant line, allowing the spacecraft to resume operations with its electric thrusters by mid-June, the agency said Tuesday.
The spacecraft, which launched in October 2023 to study the metal-rich asteroid Psyche, experienced a drop in pressure in early April that forced a shutdown of its ion propulsion system. NASA engineers later identified the cause as a malfunctioning valve obstructing xenon flow in the primary propellant line.
“In a recent analysis, engineers concluded that a component in a valve is no longer functioning as expected and is obstructing the flow of xenon to the thrusters,” NASA said in a statement. The agency opted to switch to a backup line, where the same type of valve will be kept open to avoid a repeat of the issue.
The ion thrusters are critical to Psyche's long-duration cruise through deep space. Combined with a gravity assist maneuver around Mars in May 2026, they will help guide the spacecraft to its destination — the asteroid Psyche — by August 2029.
The mission, valued at $1.2 billion, is part of NASA's Discovery-class planetary science program. It has previously faced delays and cost overruns due to development issues, pushing its launch back more than a year and inflating its original budget by 20%. The recent valve problem was the first major anomaly reported since launch.
Once at its target, Psyche will enter orbit around the asteroid to study its composition and structure. Scientists believe the metallic body may be the exposed core of an early planetesimal, offering a unique window into the building blocks of terrestrial planets.