On June 24, Japanese company ispace held a press conference on the reasons for the crash of the Resilience spacecraft. Experts confirmed the initial assumption that the accident was caused by a malfunction in the laser range finder.
The Resilience spacecraft was launched in January 2025. It was ispace’s second attempt to reach the moon. Its first lunar lander, Hakuto-R, crashed in 2023 during descent. The cause of the accident was a software error in the lander.
After a 3.5-month flight, which included several gravitational maneuvers, Resilience entered orbit around the Moon. Over the next month, the spacecraft gradually lowered its orbit while engineers prepared for its landing.
Resilience began landing on June 5. For most of the operation, the Japanese spacecraft descended normally. However, shortly before landing, contact with it was lost. Later, the American LRO probe photographed the trace left on the lunar surface after Resilience’s fall.
Immediately after the accident, ispace reported that they believed the most likely cause of the accident was a malfunction in the laser range finder used to determine the exact distance to the surface. At a press conference held on June 24, company representatives confirmed this assumption. According to experts, the range finder transmitted data with a delay, which led to an incorrect determination of the distance to the surface. At the moment of losing contact, Resilience was at an altitude of 192 meters, descending at a speed of 42 meters per second. Five seconds later, it crashed.
According to calculations by astronomer Scott Manley, if Resilience had been just 200 meters higher at the moment of communication loss, the spacecraft would have been able to make a soft landing, taking into account its braking.
Based on a deceleration of 2.4m/s^2 they would have taken 17.5 seconds to decelerate – 368metres would be the stopping distance. They had 192m left at that point.
So after flying millions of km they missed their deceleration point by less than 200m
— Scott Manley (@DJSnM) June 24, 2025
ispace engineers considered two main versions of a possible malfunction of the range finder. The first is an error in the installation of the equipment or incorrect orientation of the device during descent. The second hypothesis suggests that the device degraded during flight or that its performance was initially lower than expected. For now, experts tend to favor the second version.
Of the seven attempts to land on the moon undertaken by private companies in recent years, only one can be considered completely successful. We are talking about Firefly Aerospace’s Blue Ghost spacecraft, which landed on the moon in March. Blue Ghost was launched together with Resilience on a Falcon 9 rocket.
Despite two consecutive failures, ispace continues to prepare for its third attempt to land on the moon. It is scheduled for 2027. The landing site for the spacecraft will be the 320-kilometer Schrödinger crater, located near the Moon’s South Pole.
According to Phys.org
