Will Japan's Moon lander survive the freezing temperatures of the lunar night?

The country became the fifth nation to softly land on the lunar surface

Japan's Slim Moon vehicle landed upside down on the lunar surface. Photo: Jaxa

Japan's Moon lander has been put back to sleep for two weeks to help it survive the lunar night, when temperatures plunge to -183°C.

Japan became the fifth nation to softly touch down on the Moon with the Smart Lander for Investigating the Moon (Slim) vehicle on January 19, although images released a week later showed that it had landed upside down.

Jaxa, the country's space agency, said after the landing that Slim's solar cells were not working properly, probably due to the incorrect orientation, forcing the agency to put the vehicle in hibernation mode.

It was revived a few days ago, and some science data was beamed back to mission control, but now it has been put back to sleep.

“Slim entered a two-week dormancy period during the long lunar night,” Jaxa posted on X, formerly Twitter, on Thursday.

“Although Slim was not designed for the harsh lunar nights, we plan to try to operate again from mid-February, when the Sun will shine again on Slim’s solar cells.”

Slim used precision-landing technology that allowed it to touch down close to the designated spot on the surface.

The lightweight probe was sent to the Moon so engineers could improve the technology for exploration missions.

Before Japan, only the US, the former Soviet Union, China, and India in 2023, had managed a soft landing on the lunar surface.

Attempts were made in 2019 by India and Israel, Russia in 2022, by Japanese company ispace last year and an American company this year, but all failed.

India's moon lander Vikram and Pragyan rover operated on the Moon during the lunar day, which lasts about 14 days, but they did not survive the lunar night.

Soft landing is when a vehicle touches down gently on the Moon's surface without crashing, so that its hardware and instruments stay intact.

Moon-landing vehicles cannot use parachutes to slow for a touchdown as they can on Earth and Mars.

Instead, they need to use thrusters to brake and adjust their positioning to land softly on the surface.