Defying the odds, Japan's SLIM lander survives 2nd night on the moon

Japan's SLIM moon lander captured this view of its landing site shortly after surviving its second lunar night. The mission team posted this photo via X on March 27, 2024.
Japan's SLIM moon lander captured this view of its landing site shortly after surviving its second lunar night. The mission team posted this photo via X on March 27, 2024. (Image credit: JAXA)

SLIM's not dead yet.

The SLIM spacecraft, Japan's first-ever successful moon lander, has survived the long, cold lunar night for the second time.

Mission team members announced the news via X on Wednesday (March 27), in a post that also featured a photo newly snapped by the lander's navigation camera.

SLIM, whose name is short for "Smart Lander for Investigating Moon," launched last September and landed on Jan. 19, making Japan just the fifth nation to pull off a soft lunar touchdown. (The other four are the Soviet Union, the United States, China and India.)

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The solar-powered SLIM landed on its nose that day, a less-than-optimal orientation for harvesting sunlight. The 440-pound (200 kilograms) probe went dark shortly thereafter but then woke up on Jan. 28 and began gathering data.

The mission team put SLIM into hibernation a few days later ahead of the two-week-long lunar night, during which surface temperatures at its locale dropped to around minus 208 degrees Fahrenheit (minus 130 degrees Celsius).

SLIM had already achieved its primary mission goals — making a precision touchdown, deploying two tiny rovers and conducting a variety of science work — by that point and was not expected to open its eyes again. But the probe did so, waking up late last month.

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SLIM now has a second revival under its belt, though the extreme conditions are beginning to take their toll on the plucky little robot.

"According to the acquired data, some temperature sensors and unused battery cells are starting to malfunction, but the majority of functions that survived the first lunar night was ma[i]ntained even after the second lunar night!" mission team members said in another X post on Wednesday night.

SLIM's January touchdown was followed a month later by that of Odysseus, which was built and operated by Houston-based company Intuitive Machines. Odysseus' lunar touchdown was the first ever by a private spacecraft and the first for an American vehicle since Apollo 17 in 1972.

Odysseus operated for a week on the lunar surface, then went silent ahead of its first lunar night. And that silence is forever; Intuitive Machines announced earlier this week that Odysseus' mission is over.

Originally posted on Space.com.

Mike Wall
Space.com Senior Writer
Michael was a science writer for the Idaho National Laboratory and has been an intern at Wired.com, The Salinas Californian newspaper, and the SLAC National Accelerator Laboratory. He has also worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz.