Peregrine Spacecraft Suffers Propellant Leak After Successful Rocket Launch

January 11, 2024

An image of Peregrine in space taken from a camera mounted on top of one of its payload decks. (Image: Astrobotic)

Astrobotic's Peregrine lunar lander suffered a failure within its propulsion system after deploying from the United Launch Alliance (ULA) Vulcan Centaur rocket on its intended journey to the Moon. The company released a series of updates about the Peregrine mission, which was successfully launched on Jan. 8 with the intention of becoming the first U.S.-launched landing on the Moon since the Apollo program.

Peregrine was successfully deployed into space following its launch onboard the Vulcan rocket on what was planned to be a 46-day journey to the lunar surface. However, after separating from the rocket, the lunar lander's propulsion system experienced an anomaly that prevented it from achieving a stable sun-pointing orientation.

According to several updates released by Peregrine on its X account, the Peregrine mission team was eventually able to reorient the spacecraft's solar array toward the Sun to recharge the battery and give it full operational power. But the team discovered that the failure in Peregrine's propulsion system lead to a critical loss of propellant that will likely prevent it from making the intended lunar surface landing it was launched for.

One of Astrobotic’s latest reported updates on the mission noted the following on Jan. 9:

"Given the propellant leak, there is, unfortunately, no chance of a soft landing on the Mon. However, we do still have enough propellant to continue to operate the vehicle as a spacecraft. The team has updated its estimates, and we currently expect to run out of propellant in about 40 hours from now...We are in a stable operating mode and are working payload and spacecraft tests and checkouts. We continue receiving valuable data and proving spaceflight operations for components and software relating to our next lunar lander mission, Griffin."

Peregrine was launched with 21 different payloads from governments, companies, universities, and NASA’s Commercial Lunar Payload Services (CLPS) program. It was originally intended to attempt a soft landing at the Gruithuisen Domes on the Moon and support lunar surface payload operations for 10 days. CLPS is also a central part of NASA's Artemis lunar exploration program.

NASA released a statement following the discovery of the propulsion system issue, noting its intention to support Astrobotic's attempt to understand the root cause of the failure.

“There are many challenges with spaceflight, and we’re incredibly proud of the Astrobotic and NASA teams that have put us one step closer to a robotic return to the lunar surface as part of Artemis. This delivery service model is a first for the agency and with something new, there is a higher risk,” said Joel Kearns, Deputy Associate Administrator for Exploration at NASA’s Science Mission Directorate. “NASA is committed to supporting our commercial vendors as they navigate the very difficult task of sending science and technology to the surface of the Moon.”

Copies of four of the NASA payloads aboard Peregrine are expected to fly on future flights including the Laser Retroreflector Array, Near-Infrared Volatile Spectrometer System, Neutron Spectrometer System, and Linear Energy Transfer Spectrometer. The Peregrine Ion-Trap Mass Spectrometer is not currently on a future CLPS flight, according to NASA.

One working theory released by Astrobotic about the cause of the propulsion system failure is that a valve between the helium pressurant and the oxidizer failed to reseal after actuation during initialization. Astrobotic’s working theory further posits that this lead to a rush of high-pressure helium that spiked the pressure in the oxidizer beyond its operating limit and ruptured the tank.

A formal review board is working on a full analysis report of the propulsion system failure.

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