Friday, February 02, 2024

Japan's SLIM moon lander snaps final photos before going dormant during lunar night

Andrew Jones
Thu, February 1, 2024 

Black and white photos of the rocky grey surface of the moon.


Japan's historic SLIM moon lander has powered down ahead of a likely mission-ending cold lunar nighttime — but not before grabbing some final images and loads of science data.

SLIM, short for "Smart Lander for Investigating Moon," nailed its precision touchdown on the rim of Shioli crater on Jan. 19, despite engine troubles that saw it land nose-down. As a result, the spacecraft's solar cells face westward and are unable to receive the expected levels of sunlight, initially cutting operations on the lunar surface very short. But SLIM triumphantly reawakened nearly 10 days after landing, as the sun finally shone on its panels.

Related: Japan's SLIM moon lander photographed on the lunar surface — on its nose (image)


Image of the lunar surface captured by a japanese lander, showing gray dirt, small rocks and a hill in the distance. Some of the rocks are circled in yellow.


The Japan Aerospace Exploration Agency (JAXA), which operates SLIM, has spent recent days scanning the nearby lunar surface with the spacecraft's Multi-Band Camera (MBC) to learn about its composition.

MBC is designed to scope out olivine and other minerals through analyzing the light signatures, or spectra, of reflected sunlight, according to the nonprofit Planetary Society.

JAXA's SLIM account on X, formerly Twitter, posted a final image taken by SLIM's navigation camera on Jan. 31 Japan time, while stating that the agency confirmed the spacecraft had entered a dormant state as expected.

JAXA will need to wait out the roughly 14.5-Earth-day-long lunar nighttime and then wait for favorable lighting and temperature conditions later in the next lunar daytime (which starts around Feb. 15) before SLIM can potentially be revived once more. For the probe to awake again, however, its electronics must hold up in the face of equatorial lunar nighttime temperatures of around minus 208 degrees Fahrenheit (minus 130 degrees Celsius).

But whether or not SLIM wakes up, the spacecraft has hit its full and extended mission goals by achieving a precision landing, deploying a pair of small rovers and demonstrating their interoperability, and obtaining a wealth of science data.

SLIM's X account also posted labeled images of targets of MBC's spectroscopic imaging, showing the various rocks and regolith that are being studied.


closeup view of a large rock on the lunar surface, with smaller rocks surrounding it.

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"Based on the large amount of data we have obtained, we are proceeding with analyses to identify rocks and estimate the chemical composition of minerals, which will help solve the mystery of the origin of the moon," a Google machine translation of a Feb. 1 JAXA statement read.

"We will announce scientific results as soon as they are obtained," the statement added.

Lunar night puts Japan's lander back to sleep

AFP
Thu, February 1, 2024 

Japan's SLIM lunar lander seen in an image credited to JAXA, Takara Tomy, Sony Group Corporation and Doshisha University (Handout)


After a brief awakening, Japan's Moon lander is out of action again but will resume its mission if it survives the two-week lunar night, the space agency said Thursday.

The unmanned Smart Lander for Investigating Moon (SLIM) touched down last month at a wonky angle that left its solar panels facing the wrong way.

As the sun's angle shifted, it came back to life for two days this week and carried out scientific observations of a crater with its high-spec camera.

"After completing operation from 1/30 (to) 1/31, #SLIM entered a two week dormancy period during the long lunar night," space agency JAXA said on X, formerly Twitter.

"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."

JAXA said SLIM was able to "successfully complete observations... as originally planned" with its multiband spectroscopic camera and could study more target areas than initially expected.

The space agency also on Thursday posted a black-and-white photo of the rocky surface taken by the spacecraft.

It followed other grainy images sent back from the mission to investigate an exposed area of the Moon's mantle, the inner layer usually deep beneath its crust.

SLIM, dubbed the "Moon Sniper" for its precision landing technology, touched down within its target landing zone on January 20.

The feat was a boon for Japan's space programme after a string of recent failures, making the nation only the fifth to achieve a "soft landing" on the Moon, after the United States, the Soviet Union, China and India.

But during its descent, the craft suffered engine problems and ended up on its side, meaning the solar panels were facing west instead of up.

Russia, China and other countries from South Korea to the United Arab Emirates are also trying their luck to reach the Moon.

US firm Astrobotic's Peregrine lunar lander began leaking fuel after takeoff in January, dooming its mission. It likely burned up in the Earth's atmosphere on its return.

NASA has also postponed plans for crewed lunar missions under its Artemis programme.


Japan’s SLIM Lunar Lander Is Still Alive, Despite Landing Upside-Down

Cassidy Ward
Wed, January 31, 2024 

The events of SYFY’s The Ark (streaming now on Peacock) take a few liberties with their portrayal of space exploration, but the show gets one thing absolutely correct: things go wrong in space. All of the planning, testing, and dress rehearsals can’t compare to actually launching something into the abyss, and it’s almost guaranteed that mission controllers will run into problems they didn’t account for.

The 4.2 light-year trip to Proxima centauri provides plenty of opportunities for our fictional crew to encounter mishaps, but real-world scientists run into similar problems much closer to home. Recently the Japan Aerospace Exploration Agency (JAXA) launched a lunar lander to the surface of the Moon, and things didn’t go according to plan. For a minute there, it seemed that the agency’s SLIM lander, short for Smart Lander for Investigating Moon, was basically dead on arrival.

In actuality, it just needed a little nap while waiting for more favorable conditions. After more than a week in stasis, SLIM woke up and is busily snapping pictures from the surface of the Moon.
SLIM’s Trip to the Moon was a Mixture of Failure and Success

SLIM launched September 6, 2023, and took a leisurely, several-month trip to the Moon. It entered into lunar orbit toward the end of the year and made its final approach, landing on January 19, 2024. After a tense descent, SLIM touched down at Shioli Crater, near the Moon’s equator. The achievement made Japan only the fifth nation to successfully soft-land a craft on the lunar surface, but it wasn’t without speed bumps.

For More on the Moon:
The Moon Is Shrinking, Triggering Fault Lines and Moonquakes
Watch Russia's Crashed Luna-25 Punch a New Crater into the Moon's Surface
India's Chandrayaan-3 Successfully Lands on the Moon's South Pole

An image of the SLIM lander on the Moon, captured by Lunar Excursion Vehicle 2 (LEV-2)
Photo: JAXA

Something went wrong in the last moments of descent, and it wasn’t immediately clear what had happened. Mission controllers knew that the solar cells weren’t collecting energy from the Sun as planned, but it took days to figure out why. Over the course of the first few hours, the lander’s onboard battery fell to 12% charge and JAXA made the decision to power the lander down. It was a strategic move, leaving enough energy in the batteries to power the lander back up if and when the solar cells caught light.

In the meantime, JAXA confirmed that SLIM achieved its primary mission, landing approximately 55 meters from its intended target, making it the most precise landing ever achieved on the Moon. For contrast, Apollo 11 touched down roughly 6 kilometers (3.7 miles) away from its target.


JAXA's SLIM Lander Wakes Up After 9 Days in Stasis

An ongoing investigation into the cause of the Moon mishap suggests that one of the lander’s main engines lost thrust about 50 meters from the surface. It seems that the engine loss caused the lander to start flying sideways, tip over, and land on the Moon upside-down. Fortunately, two autonomous probes that detached from SLIM before things went sideways provided an outside perspective into what went wrong.

One of the probes, dubbed LEV-2, was able to snap a photo of the lander on the surface (above), confirming its upside-down orientation. Moreover, the solar cells were pointed away from the Sun, explaining why they didn’t start juicing the batteries after landing. That’s obviously not what JAXA was hoping for, but it also provided some hope that the lander might wake up at some future date. To understand why, let’s consider the sundial.

Sundials work by casting a shadow to mark the time. It’s an effective, if archaic, way of telling time because the sunlight’s angle of approach changes as a planet (or moon) rotates around its axis. On Earth, that happens once every 24 hours (give or take), but a day on the Moon is much longer. Because the Moon is tidally locked to the Earth, it only completes a circuit once every orbit, roughly every 29.5 Earth days. If SLIM had any chance of waking up, it would be when the Sun’s angle of attack shifted to hit the solar cells.


Surface of the moon.

A lunar surface scan mosaic image captured by the SLIM-mounted MBC. Rocks of interest have been given nicknames taken from various dog breeds. Photo: JAXA, RITSUMEIKAN UNIVERSITY, THE UNIVERSITY OF AIZU

On January 28, JAXA announced on X (the website formerly known as Twitter) that the lander had woken up. After 9 days in limbo, the solar cells picked up sunlight and the topsy-turvy lander made contact. Despite being head over heels, SLIM fired up its multi-band camera and started taking pictures of the nearby lunar surface. It will keep snapping photos, investigating the mineral composition of the nearby landscape, until the Sun sets on that part of the Moon and SLIM goes to sleep, probably forever.

Already, the precision landing made SLIM an incredible success and a feather in JAXA’s cap, but its ability to land on its head and just keep going is a monument to engineering. Not bad, SLIM. Not bad.

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