The Psyche spacecraft launched nearly two years ago and is currently on its way to rendezvous with a unique asteroid in an effort to understand the origins of Earth. Although it’s still a few years away from orbiting the asteroid, which bears the same name, the Psyche mission has run into an issue with its propulsion system that forced it to power off its thrusters.
NASA engineers with the Psyche mission are investigating the root cause of a recent decrease in fuel pressure in the spacecraft’s propulsion system, an issue that needs to be resolved before mid-June so that it doesn’t affect the mission’s trajectory. “The mission team has chosen to defer thrusting while engineers work to understand the pressure decrease,” NASA wrote in an update.
Psyche launched in October 2023, beginning a 2.2 billion-mile journey to a metal-rich asteroid located in the main belt. The spacecraft began firing its thrusters in May 2024, using a solar electric propulsion system that relies on solar energy to generate power for four electric thrusters. On April 1, the spacecraft detected a pressure drop in the line that delivers xenon gas to the thrusters, which went from 36 pounds per square inch (psi) to about 26 psi, according to NASA. In response to the sudden decrease, the spacecraft automatically powered off its thrusters.
The mission can keep its thrusters turned off for another month and a half before it’s too late—when the probe needs to adjust its trajectory. As it works to figure out what may have caused the drop in fuel pressure, the team of NASA engineers is also considering switching to the spacecraft’s backup fuel line so that it can resume firing its thrusters.
If all goes well, the spacecraft will enter asteroid Psyche’s orbit in late July 2029 and begin its mission in August of the same year. The mission is scheduled for a flyby of Mars in spring 2026, using the planet’s gravitational pull to slingshot it toward the main asteroid belt that’s located between Mars and Jupiter. Psyche is a 140-mile-wide (226-kilometer) asteroid which may be the stripped-down core of a shattered planetesimal, one of the building blocks that come together to form a planet.
The mission has been a long time in the making, and has run into its fair share of issues. Psyche was originally scheduled to launch in 2022, but an issue with the spacecraft’s flight software delayed the mission until its next launch window the next year. The spacecraft’s flight software controls its orientation and trajectory, as well as its ability to send and receive data to Earth. A week before its original launch date on October 5, 2023, engineers discovered an issue with the Psyche spacecraft’s thrusters that could have caused it to overheat during its eight-year mission. As a result, the mission’s liftoff date was delayed by one week as the team resolved the issue.
NASA officials don’t seem too concerned about the problem. “This kind of thing happens and that’s why we build redundancy into our missions,” Louise Prockter, director of NASA’s planetary science division, said during a meeting of the Mars Exploration Program Analysis Group on Wednesday, SpaceNews reported. “We don’t have any concerns at the moment about it but we’re obviously keeping tabs on it.”