NASA’s Psyche Spacecraft Using Backup Fuel Line

Engineers with NASA’s Psyche mission have developed a solution to address the decrease in fuel pressure they detected recently in the spacecraft’s propulsion system: They have successfully switched to a backup fuel line, which is operating as expected.

Powered by two large solar arrays, Psyche’s thrusters ionize and expel xenon gas to gently propel the spacecraft, which gradually picks up speed during its journey. The team paused the four electric thrusters in early April to investigate an unexpected drop in pressure. They determined that a mechanical issue in one of the valves, which open and close to manage the flow of propellant, caused the decrease. Through extensive testing and diagnostic work, the team concluded that a part inside one of the valves is no longer functioning as expected and is obstructing the flow of xenon to the thrusters.

Now that the swap to the backup fuel line is completed, engineers will command the spacecraft’s thrusters to resume firing by mid-June.

The spacecraft was designed with a redundant backup propellant line that is identical to the primary propellant line. Engineers plan to keep the backup line’s valve in the open position to ensure propellant flow and avoid any potential mechanical issues in the future.

The orbiter remains on course to reach the asteroid Psyche as planned in August 2029. The spacecraft launched from NASA’s Kennedy Space Center in Florida in October 2023 and already has flown 628 million miles (1 billion kilometers). In May 2026, Psyche will fly by Mars, using the planet’s gravity as a slingshot to help speed the orbiter along to the metal-rich asteroid it was built to explore.