Japan’s uncrewed "moon sniper" lander has encountered a serious technical issue with its solar cells immediately after touching down on the lunar surface, which could see its lithium-ion batteries run dry in a matter of hours.
The Japanese space agency’s (JAXA) Smart Lander for Investigating Moon spacecraft - known colloquially as "moon sniper," or SLIM - launched in September 2023 with a mission to perform the most accurate lunar landing in history. According to JAXA, missions to the Moon usually attempt to touch down within 7-10 km of the desired landing point using autonomous systems that compare images of the Moon's surface with maps stored aboard the descending spacecraft. SLIM, meanwhile, was set the target of landing within 100 meters of its desired landing site - the edge of an impact site known as the Shioli crater, which is located in the Mare Nectaris region near the lunar equator.
This location was chosen due to its potential to play host to ancient matter ejected from deep within the Moon's mantle, an analysis of which could shed light on the theory that the Moon was formed from material cast into space in the distant past, following an impact between Earth and an unknown protoplanet.
＼Finally from 23:00 JST today／
— JAXA Institute of Space and Astronautical Science (@ISAS_JAXA_EN) January 19, 2024
[SLIM Moon landing: live broadcast ?]
Jan. 19 (Fri) 23:00~ JST
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Please support SLIM as they take on the challenge of a high-precision pinpoint landing✨
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On January 19, the SLIM spacecraft began its final descent from a height of 15 km above the moon’s surface. At 5 km, the spacecraft orientated its two main engines towards the ground, and began its vertical descent. Minutes later, at just 50 meters above the surface, SLIM initiated a brief hover manouvre, while using its cameras to scan the landing zone for potential hazards. In the final stages, the spacecraft was meant to fire a secondary set of thrusters designed to pitch it onto a set of supports arrayed on one side, which would absorb the impact of landing. However, It is not yet clear whether this stage of the mission unfolded exactly as expected.
In a press conference following the landing, JAXA revealed that it was able to successfully establish communication with the spacecraft, and confirm that it had successfully deployed two rovers to the lunar surface. However, it was also revealed that the spacecraft’s solar cells, which cover the upper side of the spacecraft, had encountered an issue, and were not generating the electricity needed to replenish the probe’s lithium ion batteries.
At the time of writing the SLIM lander’s batteries are thought to have ‘several hours’ of energy remaining, leaving JAXA racing to transmit as much information as possible back to Earth in the form of navigational data and imagery before they run dry. JAXA representatives also emphasised that there is a chance that the lander could be revived in a few weeks following a period of lunar night, when a shift in the angle of sunlight could allow SLIM’s solar cells to obtain more light, and recharge the batteries.
It is also possible that mission handlers could attempt to communicate and perform operations using the two small rovers deployed to the lunar surface, one of which has a transmitter of its own. It will take time for JAXA to analyze the data from SLIM in order to discover the cause of the anomaly, and to gauge how successful the pinpoint landing approach truly was. However, regardless of the scientific output, Japan has successfully made history by becoming only the fifth nation to have a spacecraft survive a "soft" landing attempt on the Moon.
The first ever spacecraft to survive the journey to the lunar surface was the then Soviet Union’s Luna 9 (Lunik 9) spacecraft on February 3 1966, which was followed mere months later by America’s Surveyor 1 lander. Over half a century later the Chang’e 3 mission would mark China’s first mission to the Moon, while India’s lunar debut would come in 2023, courtesy of the Chandrayaan-3 lander.
Anthony is a freelance contributor covering science and video gaming news for IGN. He has over eight years experience of covering breaking developments in multiple scientific fields and absolutely no time for your shenanigans. Follow him on Twitter @BeardConGamer
Image credit: NASA/Goddard/Lunar Reconnaissance Orbiter
