Japan’s Smart Lander Slim Successfully Lands on Moon but Lunar Mission at Risk of Ending Soon

A Japanese robot successfully landed on the Moon. However, the mission might be short-lived due to problems with its solar power system.

Japan's SLIM Landed on the Moon But With Some Glitch

Near an equatorial crater, the Smart Lander for Investigating Moon (Slim) gently touched down on the lunar surface on Jan. 19. With this accomplishment, the Asian nation joined the US, the Soviet Union, China, and India as the only other nations to soft-land on an Earthly satellite.

But now, engineers are fighting to keep the mission alive. The craft's solar cells will not produce electricity for reasons that are completely unknown now.

Due to the problem in its power system, Slim is solely dependent on its batteries, which will ultimately run out. Eventually, the lander won't be able to communicate with Earth or accept commands.

Engineers are setting priorities for their work. They are pulling down photos from the craft and turning off the heaters. Additionally, they are retrieving data that will indicate the effectiveness of the landing software.

If Slim goes silent, Japanese space agency (Jaxa) officials will not abandon it immediately. According to them, there's always a chance that the solar cells' orientation has changed, making it impossible for them to see the Sun. The officials were hopeful that Slim might resurrect when light angles on the Moon shift.

Hitoshi Kuninaka, vice president of JAXA, responded in the affirmative when asked if Japan could legitimately claim a soft landing during a press conference.

"If powered descent wasn't successful, then there would have been a collision with the surface at a very high speed and spacecraft function would have been completely lost," he told reporters.

"But it is still sending data properly to us, which means our original objective of a soft landing was successful."

Slim was carrying two small rovers, and telemetry indicates it managed to eject these as planned just before touchdown.

What Is Slim?

A Japanese H-2A rocket, which carried the SLIM moon lander and the XRISM space telescope, launched from Tanegashima Space Center on Sept. 7. The launch took place approximately ten days later than planned due to weather-related delays. After takeoff, one hour exactly, both spacecraft were deployed without incident. The lander landed on the Moon four months later.

SLIM is a tiny spacecraft with dimensions of just 5.6 feet (1.7 meters), 7.9 feet (2.4 meters) in height, and 8.8 feet (2.7 meters) in length. At liftoff, it weighed around 1,540 pounds (700 kg), although propellant made up roughly 70% of its weight.

XRISM (X-Ray Imaging and Spectroscopy Mission) is the principal spacecraft in low Earth orbit. The European Space Agency (ESA), NASA, and the Japan Aerospace Exploration Agency (JAXA) are collaborating on the XRISM project. As its full name implies, the telescope will study the universe using high-energy X-ray photons.

By enabling humans to land anywhere they choose, instead of where it's convenient, the SLIM lander will allow humanity to advance in this area significantly. This will enable human habitation of worlds with much lower resource levels than the Moon.

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