Japan Moon lander survives lunar night

Japan's Moon lander, Slim, has survived the harsh lunar night and rebooted itself after a period of shut down.


Slim Survives Lunar Night

Japan's Moon lander, Slim, has successfully survived the sunless and freezing lunar night, which lasted equivalent to two Earth weeks. Despite an awkward landing in January that left its solar panels facing the wrong way and unable to generate power, the lander received a command and responded after being put into sleep mode.

Jaxa, the national space agency, said that Slim was not designed to endure the harsh lunar nights, but a change in sunlight direction allowed it to send pictures before shutting down again. The agency plans to resume operations in mid-February, when the Sun will shine on Slim's solar cells once again.

Dr Simeon Barber from the UK's Open University described the news of Slim's reboot as significant and explained that surviving lunar night is a key technological challenge to establish long-lived missions on the Moon.

Challenges of Lunar Night

Slim, which landed near the Moon's equator, experienced extreme temperature fluctuations during the lunar night. The lunar surface reached over 100C at noon and then plunged to -130C at night. According to Jaxa, communication with the lander was terminated due to high temperatures of the communications equipment during lunar midday.

Preparations are underway to resume operations once instrument temperatures have cooled sufficiently. During its previous re-awakening, Slim was able to study its surroundings and transmit new images to Earth, giving hope for continued work from the lander.

Dr Barber highlighted the need for 'active' thermal control in future landers to prevent extreme temperature variations. However, Slim's survival without such complex design may provide valuable insights into the behavior of electronics on the Moon.

Achievements and Congratulations

Jaxa congratulated the team behind the US spacecraft, the Odysseus Moon lander, for becoming the first privately built and operated robot to achieve a soft lunar touchdown. Although the landing was also awkward, the robot appears to be functional and is communicating with Earth.

This landing made Jaxa the fifth national space agency to achieve a soft touchdown on the Moon, following the US, the former Soviet Union, China, and India. No pictures from the Odysseus mission at the lunar surface have been released yet.