Ispace publishes results of its investigation into Hakuto-R1 lunar landing failure

Before and after images of Hakuto-RI, taken by Lunar Reconnaissance
Orbiter (LRO). Click for original blink image.
Ispace today published the results of its investigation into the failure of its Hakuto-R1 lunar landed to touch down on the moon successfully, stating that the cause was a software error which thought the spacecraft was closer to the ground than it was.
At the end of the planned landing sequence, it approached the lunar surface at a speed of less than 1 m/s. The operation was confirmed to have been in accordance with expectations until about 1:43 a.m., which was the scheduled landing time.
During the period of descent, an unexpected behavior occurred with the lander’s altitude measurement. While the lander estimated its own altitude to be zero, or on the lunar surface, it was later determined to be at an altitude of approximately 5 kms above the lunar surface. After reaching the scheduled landing time, the lander continued to descend at a low speed until the propulsion system ran out of fuel. At that time, the controlled descent of the lander ceased, and it is believed to have free-fallen to the Moon’s surface.
The company believes the software got confused when the spacecraft crossed over the rim of Atlas Crater.
The resulting crash produced the debris seen by LRO to the right.
Before and after images of Hakuto-RI, taken by Lunar Reconnaissance
Orbiter (LRO). Click for original blink image.
Ispace today published the results of its investigation into the failure of its Hakuto-R1 lunar landed to touch down on the moon successfully, stating that the cause was a software error which thought the spacecraft was closer to the ground than it was.
At the end of the planned landing sequence, it approached the lunar surface at a speed of less than 1 m/s. The operation was confirmed to have been in accordance with expectations until about 1:43 a.m., which was the scheduled landing time.
During the period of descent, an unexpected behavior occurred with the lander’s altitude measurement. While the lander estimated its own altitude to be zero, or on the lunar surface, it was later determined to be at an altitude of approximately 5 kms above the lunar surface. After reaching the scheduled landing time, the lander continued to descend at a low speed until the propulsion system ran out of fuel. At that time, the controlled descent of the lander ceased, and it is believed to have free-fallen to the Moon’s surface.
The company believes the software got confused when the spacecraft crossed over the rim of Atlas Crater.
The resulting crash produced the debris seen by LRO to the right.