What Went Wrong with the Peregrine Moon Lander and What It Means for Future Lunar Missions

On January 8, 2024, the Peregrine lunar lander launched from Cape Canaveral aboard a next-generation Vulcan Centaur rocket.

The spacecraft was the latest in a surge of private sector efforts to return payloads and even humans to our nearest neighbour. Developed by lunar transportation firm Astrobotic Technology, it carried an ambitious payload of instruments, research projects, and commemorative items assembled by partners throughout the aerospace industry and beyond. Packed in the approximately 1,300-kilogram probe was a diverse array of scientific missions, technology demonstrations, educational experiments, and commercial offerings.

The lander was planned to touchdown in the Gruithuisen region of the Moon on February 23 and usher in a new era of low-cost access to lunar services. However, only seven hours after riding the fiery Vulcan rocket upwards from Florida’s Space Coast did initial signs of trouble for Peregrine begin to surface.

As mission control attempted to reorient Peregrine’s solar panels to point towards the Sun for charging, the spacecraft was sluggish to respond. The latest analysis has determined that this abnormal behaviour originated from a lander’s propulsion system failure.

Reports indicated that this breakdown was causing a gradual loss of fuel and propellant reserves. Peregrine’s attitude control thrusters worked overtime to maintain an essential Sun-facing position to prevent an uncontrolled spin and potential loss of communication or power. But their limited capacity, coupled with the fuel leak, positioned the Mission on borrowed time.

Above – An image released by Astrobotic shows damage to the craft

Propellant would only last an estimated 40 additional hours based on observed drain rates before the guidance system could no longer fight the tendency to tumble in space.

Timeline of propulsion and orientation issues after separation:

• Stable pointing failure 7 hrs after launch
• Off-nominal manoeuvre to reorient solar panels
• Gradual propellant leak identified as root cause
• Thrusters operating beyond expected capacity to maintain pointing
• Prediction of 40 hr lifespan based on depletion rate
• The first image shows external damage from issues

The fast depletion also doomed any prospect of achieving a controlled touchdown on the lunar terrain. Safely settling onto the surface requires precise alignment from the engine and carefully timed burns to arrest downward motion. With minimal capacity left in the tanks, there was no way for Peregrine to perform the necessary steps for a stable landing.

And unlike previous robotic Moon probes, this vehicle was not designed to withstand the frigid 14-day lunar night without power. Any high-speed crash landing would almost certainly spell doom for the sensitive components packed aboard. As electronics and science labs went dark, years of development work by contributing academic institutions and private companies would be lost instantly.

Faced with the inevitable, Astrobotic shifted to maximizing whatever extra value it could from Peregrine’s remaining moments of operation. With available thrust barely able to keep solar cells trained on their energy source, mission control decided to forgo the planned landing. Instead, they committed to guiding the ailing lander as near as possible to lunar orbit for its final days in space. From this distance, partners would still have an opportunity to gain insights into how their creations fared during launch and transit to deep space. Any telemetry returned could prevent future setbacks or spot flaws in resilience to extreme conditions.

Above – What the Peregrine would have looked like if it had touched down safely 

While this change of plans represented an optimistic attempt to rescue a mission that otherwise might have been a complete loss, it still dealt a blow to many who invested financially, professionally, or emotionally in Peregrine’s success. In addition to apparatus with scientific intent like radiation monitors, mineral detectors, a laser retroreflector, and navigation tools, the initial roster of payloads included more personal effects. Capsules of human ash, a children’s time capsule, digital archives of culture and language, a Bitcoin token, and small experimental rovers numbered among the lost items and experiments.

The demise of 2024’s first Moon shot serves as a reminder of the immense technical hurdles that persist in this unforgiving domain. And with NASA still planning over a dozen private robotic lander missions as precursors to eventual crewed Artemis flights, it highlights why redundancy and deliberate pacing must define our return to deep space exploration. Each attempt manufactures hard-learned wisdom about precision orbital insertion, resilient spacecraft construction, and navigation sensor design for guiding precise powered descents. Applying these painful lessons to future missions with crew aboard will prove essential to advancing humanity’s permanent expansion beyond Earth.