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According to the Japan Aerospace Exploration Agency, Japan’s “Moon Sniper” lander has defied all odds for the third time, surviving another long, frigid moon night despite not being designed to withstand such harsh conditions.
According to NASA, temperatures during the lunar night can drop to minus 208 degrees Fahrenheit (minus 133 degrees Celsius). And Moon Sniper was not expected to survive even one lunar night, which is a period of darkness on the moon that lasts about two weeks.
The robotic vehicle, also known as SLIM, or the Smart Lander for Investigating Moon, first landed on the lunar surface on January 19. This historic achievement made Japan the third country this century, and the fifth country ever, to land on the moon. The spacecraft landed near the Shioli Crater, about 200 miles (322 kilometers) south of the Sea of Tranquility, an area near the lunar equator where Apollo 11 first landed humans on the moon.
But things didn’t quite go according to plan.
During descent, the spacecraft experienced an anomaly and landed on its nose, meaning its solar panels were facing west instead of upright and were not receiving the necessary sunlight to generate power. The lander had just enough energy to send back a mosaic of images before switching off. The mission team in Japan remained hopeful that once sunlight reached the solar panels again, the spacecraft could wake up again.
So far, Moon Sniper, who earned his nickname because of the precision technology that allowed him to land about 55 meters from his target, continues to pleasantly surprise the team by waking up after every lunar night, taking new photos and sending them back. before it goes back to sleep. The vehicle’s resilience in the face of extreme lunar conditions is unique among missions that have landed on the moon in the past year, and experts have some ideas about why that might be so.
Riding out the moon night
The mission team communicated with Moon Sniper on April 23 after the lander completed its third lunar night. The spacecraft was able to transmit more images of its landing site.
“SLIM retained its main functionality even after 3 nights on the moon, which was not anticipated in the design!” the team shared Xformerly known as Twitter.
In addition to surviving the extreme cold of the lunar night, Moon Sniper also endured Monday’s scorching temperatures, which could reach 250 degrees Fahrenheit (121 degrees Celsius), according to NASA.
The team said it is closely monitoring the condition of SLIM to identify which parts of the spacecraft could deteriorate over time as it experiences more of the moon’s day and night environments.
JAXA engineers have been careful about how they communicate with SLIM when it first wakes up because the spacecraft operates at such high temperatures, which could heat up and damage the cameras. As a result, the mission team usually waits about a day after SLIM wakes up before ordering images to be returned.
So far, one of SLIM’s navigation cameras and the spacecraft’s Star Tracker have provided images of Moon Sniper’s experiences on the lunar surface. The Star Tracker is not an actual camera and was instead used to measure the direction of the spacecraft by tracking the alignment of the stars as the lander traveled to the moon. But the team took smart measures to make the most of Moon Sniper’s shaky landing.
“It was not originally intended to be used on the lunar surface, but in principle it can take pictures just like a camera, which led to its operation via ‘secret commands’,” the agency shared on X.
The spacecraft has two navigation cameras mounted in different directions. Considering how Moon Sniper landed, one of those cameras looks into space, but the other has a view of the landing site from the spacecraft’s perspective.
According to the agency, the sun set again near Shioli Crater and Moon Sniper went back into hibernation on April 29.
“We plan to try to resume work in mid to late May, when SLIM’s solar cells will start generating electricity. We appreciate your continued support,” the agency shared on X as Moon Sniper went back to sleep.
Members of the mission team recently composed a song in honor of Moon Sniper’s inspiring journey that they called “15 degree slope.” The song covers every step of the surprise mission, from launch and journey to the moon to the unexpected landing and “resurrection awakening,” team members shared on X.
The song takes its name from the steep slope where Moon Sniper would land. Now the mission team believes the slope on which Moon Sniper landed was about 10 degrees, which is still “surprisingly steep.”
A story about two moon landings
In February, Houston-based space exploration company Intuitive Machines landed its unmanned IM-1 mission, also known as Odysseus, on the moon’s south pole, making it the first commercial spacecraft ever to soft-land on the moon and the first in US made spacecraft. vehicle to reach the lunar surface since Apollo 17 in 1972. But like SLIM, the ‘Odie’ mission had something of a rollercoaster ride on the moon, relying on experimental technology to land and ultimately landing on its side.
On February 29, after seven days of surgery, Odie went to sleep because he wasn’t supposed to survive the moon night. The Intuitive Machines team listened for Odie to wake up in March, but the spacecraft never called home again.
“Odie was designed to support only its payloads, none of which were suitable for lunar night, so we didn’t design it for anything more,” said Jack Fischer, former NASA astronaut and vice president of manufacturing and operations at Intuitive Machines. “There are measures we could have taken to potentially last longer, but we were focused on economical, fast-flown support of our payloads, as opposed to a nation-state sponsored mission.”
The fact that Odie landed near the moon’s south pole while SLIM landed near the equator could affect the lunar night’s chances of survival, Fischer said.
“It still depends on the terrain, but the equator will generally have fewer problems with shadows and more productive solar energy generation (due to the higher angles of incidence) than Odie experienced at the South Pole,” he said.
Other factors that could increase survivability include protecting a chemical battery that can withstand extreme temperatures and a design that can deliver solar energy directly to the power system, both of which could be implemented in the future.
“Night survival is critical to any effort to build meaningful infrastructure on the moon, and IM is working on a host of options with experiments once our IM-3 mission takes place,” Fischer said. “Our goal is to first ‘survive’ the night during which the spacecraft goes into a kind of hibernation (as SLIM has done) and wakes up on the other side. Ultimately, we want to be able to ‘thrive’ throughout the night, and that is exactly what we are doing with our Lunar Terrain Vehicle program, where the vehicle can do meaningful work during the lunar night.”
Fischer offered JAXA a tip of his hat about the continued success of his mission.
“While I am not an expert on the design of their vehicle, it is quite an achievement for their spacecraft to have survived three lunar nights, regardless of the conditions,” Fischer said.
A race to the moon
Japan’s success with Moon Sniper is just one entry in a renewed race to land on the moon that has been happening in recent years.
India became the fourth country to land a robotic mission on the moon in August 2023 when the Chandrayaan-3 mission landed near the moon’s south pole. The Vikram lander and the Pragyan six-wheeled rover it deployed studied the moon for almost two weeks before falling asleep during the lunar night – but attempts to wake them up were unsuccessful.
And the push for lunar exploration continues as China attempts to land a sample-collecting mission on the far side of the moon, or the side facing away from Earth, and NASA aims to establish a sustainable human presence at the south pole of to settle the moon through its ambitious Artemis program. .
Moon Sniper’s continued success comes during what Noah Petro, NASA project scientist for both the Lunar Reconnaissance Orbiter and Artemis III, calls an “amazing new era of lunar exploration.”
Six of the groundbreaking Apollo missions returned lunar samples from various landing sites on the moon, but all were on the near side of the moon. Exploring new lunar regions offers new insights into understanding Earth’s satellite.
“For me it is a great joy to see missions landing on the moon’s surface,” Petro said. “Every time we land on the surface, we learn more about this unique lunar environment we enter. Building this database of lunar knowledge about what it means to be and work on the lunar surface will help us be better prepared for the Artemis missions.”
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