The conclusion of the Peregrine lunar lander mission by Astrobotic signals the company’s shift towards a comprehensive analysis of the spacecraft’s failure and the integration of necessary modifications into a significantly larger lander designed for NASA, and a second private mission of the company.
On Jan. 19, 2024, the U.S. Space Command officially confirmed that Peregrine reentered Earth’s atmosphere on the previous day, withholding specific details regarding the time and location of reentry. Astrobotic’s initial plan aimed for a reentry in the South Pacific around 4 p.m. Eastern on Jan. 18.
News from the company
During a Press Briefing held on Thursday, John Thornton, Astrobotic’s CEO, disclosed that telemetry from the spacecraft was lost at 3:50 p.m. Eastern (20:50 UTC), followed by a loss of ranging with the spacecraft nine minutes later.
This coincided with the projected reentry at 4:04 p.m. Eastern. Independent confirmation of the reentry came later during the call through a statement from the Space Command.
The conclusion of the reentry marked the end of Peregrine’s mission, which started over 10 days prior with a successful launch atop a United Launch Alliance Vulcan Centaur rocket. A propellant leak hours after liftoff prevented a lunar landing, and the decision of allowing the spacecraft to reenter Earth’s atmosphere during its elliptical orbit was made to avoid risking a maneuver that could have corrected its trajectory.
Thornton emphasized the difficulty of the decision: “should we send this back to Earth or should we take the risk to operate it in cislunar space?” Concerns about space safety and potential catastrophic situations led to the choice of Earth impact to avoid generating more orbital debris.
The decision-making process involved consultation with NASA, the primary customer through its Commercial Lunar Payload Services (CLPS) program. Joel Kearns, NASA’s deputy associate administrator for exploration, Science Mission Directorate, noted that NASA provided recommendations on how to proceed with the mission.
Mission concludes, investigation starts
With the mission concluded, Astrobotic now focuses on investigating the causes of the failure. The leading hypothesis points to a valve failure (of course, it’s always the valves…) in a helium pressurization system, causing a rush of helium into the oxidizer side of the propulsion system, leading to a rupture.
A review board is set to convene to analyze data and confirm the cause of the propellant leak. This investigation will determine necessary corrective actions for Griffin, the larger lander being developed to transport NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) to the moon’s south polar region.
Despite Peregrine’s setback, Griffin remains on schedule for a November launch. Kearns emphasized the importance of not rushing findings that could affect the upcoming Griffin mission.
NASA will await the review results before deciding on potential modifications to the CLPS award for VIPER’s moon transport. Kearns stressed the need for a thorough understanding of the root cause: “We want to make sure we really understand the root cause and contributing factors of what happened on Peregrine.”
Thornton praised more than one time the Astrobotic team for their resilience during the truncated mission. While the primary goal of landing on the moon was not achieved, he highlighted the team’s victories in overcoming challenges, ensuring the spacecraft’s functionality in space, and collecting valuable data from onboard payloads. The data collected during flight sets the stage for future CLPS flights, providing insights into how instruments behave in space’s harsh environment.
Lastly, on a side note, we want to sincerely thank Astrobotic for their timely, precise, and comprehensive updates throughout the Mission. The company has done a great job of keeping the Press, the public, and the broader Space Community well-aware of what was happening.