SLIM Does It Again — Survives Another Lunar Night

Japan’s lunar lander is defying all the odds, surviving yet another bitter cold lunar night. The Smart Lander for Investigating Moon, or SLIM, landed in January and was expected to survive for only a few days. Instead, it woke up yesterday after a third 14-day lunar night and sent back another photo of its surroundings.

SLIM landed upside down on the lunar surface on January 19, 2024 Eastern Standard Time (January 20 in Japan) after losing an engine during descent. Most of its solar panels are facing away from the Sun and the Japan Aerospace Exploration Agency (JAXA) initially expected it would have a very short lifetime.

But once the sun angle changed and the solar panels received enough energy to recharge the lander’s batteries, it came to life and fulfilled its main task of sending back data and images. SLIM is one of the new generation of small, comparatively inexpensive lunar landers that do not have radioisotope heating units to keep batteries and instruments warm during the bitter cold 14-day lunar nights. Engineers do not expect them to survive and two others — India’s Chandrayaan-3 and the U.S. company Intuitive Machines’ Odysseus — did not.

SLIM is holding on, however. Not only did it reawaken in February after one lunar night, but again in March, and now in April after a third night.

In a post on X, JAXA posted a new image and said “Last night (4/23), we were able to communicate with #SLIM again and confirmed that it had survived its third night. Here is a photo of the surface of the moon taken last night with the navigation camera. Since this photo was taken at the earliest lunar age so far after the night, the moon is bright overall and the shadows are very short.” (translated by Google)

昨晩(4/23 夜)、再び起動した #SLIM と通信することに成功し、SLIMが３回目の越夜を達成したことを確認しました。早速航法カメラにて撮影した昨晩の月面の様子がこちらです。越夜後としてはこれまでで最も早い月齢での撮影のため、全体的に明るく影が非常に短くなっています。 #JAXA #たのしむーん pic.twitter.com/U0f88xNK9S

— 小型月着陸実証機SLIM (@SLIM_JAXA) April 24, 2024

The U.S. Lunar Reconnaissance Orbiter, in orbit around the Moon since 2009, has sent back images of SLIM on the surface. Now a camera on India’s Chandrayann-2 has been used to get another view. In a post on X, Chandra (tckb), who identifies himself as a “hobbyist/researcher nerd with a deep interest and passion for Planetary sciences, Remote Sensing and GIS,” said he located SLIM in images taken by Chandrayaan-2’s high resolution camera in March and posted three images.

???? I found @SLIM_JAXA using the Orbital high-resolution camera of @isro on board Chandrayaan-2. The below picture was captured on 2024.03.16 at a pixel resolution of 16cm per pixel! Because of the low elevation of the sun, you see long-drawn shadows.

I’ve shared three… pic.twitter.com/9PIeAoFuVb

— Chandra (tckb) (@this_is_tckb) April 24, 2024