Private Japanese moon lander crashed after being confused by a crater
The private Japanese lunar lander Hakuto-R crashed during its milestone landing attempt in late April because its on-board altitude sensor was confused by the edge of a lunar crater.
Representatives from the Tokyo-based company ispace, which built the spacecraft, revealed that the unexpected terrain feature caused the lander’s on-board computer to decide that its altitude measurement was wrong and instead rely on a calculation based on its expected altitude at that point in time. mission. As a result, the computer was convinced that the probe was lower than it actually was, leading to the April 25 crash.
“While the lander estimated its own altitude as zero, or on the lunar surface, it was later determined to be an altitude of about 5 km [3.1 miles] above the lunar surface,” ispace said in a statement released Friday (May 26). “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-falled to the moon’s surface.”
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The company said in a briefing that insufficient consideration of terrain topography around the landing side contributed to the failure, in part due to a landing site change several months before the mission’s liftoff.
Launched on a SpaceX Falcon 9 rocket in December 2022, the lander was due to touch down on April 26 on the floor of the 54-mile-wide (87 km) Atlas Crater in the Mare Frigoris (“Sea of Cold”)- region of the moon’s near side. Earlier this week, NASA’s Lunar Reconnaissance Orbiter spotted the Hakuto-R wreckage near the intended landing site.
If successful, Hakuto-R would have been the first privately powered lunar lander to achieve a lunar landing. Only NASA, China and Russia have so far soft-landed spacecraft on the moon’s surface.
Ispace emphasized that the mission successfully completed eight of its nine mission milestones and failed only in the final stages of its powered descent. The accident, company representatives said, will not affect the planned launches of ispace’s second and third missions in 2024 and 2025, respectively.
Because the failure was traced to a software issue, the future missions will not require a hardware redesign.
“Now we have been able to identify the problem during landing and have a very clear picture of how to improve our future missions,” ispace founder and CEO Takeshi Hakamada said in the statement.