There likely is little or no ice in the Moon’s permanently shadowed craters

Shadowcam-LRO mosaic
The floor of Shackleton Crater showing no obvious ice deposits,
as seen by Shadowcam. The black cross marks the south pole.
Click for original image.

This week the 55th annual Lunar and Planetary Science Conference is being held in Texas. The conference was originally established in connection with the Apollo missions to allow scientists to release their Moon research results. It quickly morphed into an annual event covering research from the entire planetary research community.

I have reviewed the abstracts for this year’s meeting, and culled what I think are the most significant new results from the conference, which I will report on in the next few posts.

We begin however with possibly the most important result from the conference, given by the science team for the ShadowCam instrument on South Korea’s Danuri lunar orbiter. That low-light camera was designed to take high resolution pictures of the permanently-shadowed craters of the Moon, to see if there was any visible or obvious ice hidden there. Though the science team presented a number of papers, the summary paper [pdf] by the instrument’s principal investigator, Mark Robinson of Arizona State University, gave the bottom line:

The data so far is finding very little evidence of water ice in these dark regions.
» Read more

Blue Origin is targeting a first unmanned landing of its manned lunar lander in 2025

Blue Origin's Blue Moon manned lunar lander
An early visualization of Blue Moon

According to one Blue Origin official, the company is now targeting its first unmanned landing of its manned lunar lander, Blue Moon, for sometime in 2025, far sooner than previously expected.

Jeff Bezos’ Blue Origin space venture is aiming to send an uncrewed lander to the surface of the moon in the next 12 to 16 months, according to the executive in charge of the development program. John Couluris, senior vice president for lunar permanence at Blue Origin, provided an update on the company’s moon lander program on CBS’ “60 Minutes” news program on Sunday. “We’re expecting to land on the moon between 12 and 16 months from today,” Couluris said. “I understand I’m saying that publicly, but that’s what our team is aiming towards.”

Blue Moon is shown in the graphic to the right. Though being built to provide NASA a second manned lander in addtion to SpaceX’s Starship, this first mission will simply bring cargo to the surface, as a test of the lander itself.

If Blue Origin can keep even somewhat close to this schedule, we will likely have two manned moon landers doing test flights at almost the same time.

A sidebar: Note the lander’s height, as well as the narrow footprint of its landing legs. New graphics of this lander from Blue Origin show the same high center of gravity with an even narrower footprint for the legs. One wonders why. Wouldn’t it make sense to have those legs deploy outward more?

This issue applies also to SpaceX’s Starship, which will also have a high center of gravity. When SpaceX’s rockets land on Earth (both Falcon 9 boosters and Starship), most of their fuel is gone so the bulk of the mass is near the bottom where the engines are, even though the boosters stand very high. On the Moon however these vehicles will be landing heavily loaded, with cargo and fuel. This raises a stability question that was illustrated sadly by the tipping over recently of Intuitive Machines Odysseus lander.

I am not an engineer, so I admit that my off the cuff analysis here is very questionable. Nonetheless, one wonders.

SLIM put back to sleep for second lunar night

Engineers at Japan’s space agency JAXA have put their SLIM lunar lander back to sleep on February 29, 2024 with the hope it might survive its second night on Moon.

“Although the probability of failure will increase due to repeated severe temperature cycles, SLIM plans to try operation again the next time the sun shines (in late March),” the update from JAXA read, automatically translated from Japanese to English by Google.

Like Intuitive Machines Odysseus lunar lander, SLIM’s overall mission was a success, as it proved it could land automatically within a very small target zone and do so softly enough that it could send back data to Earth. The failures and problems experienced by SLIM, such as having a nozzle fall off causing it land sideways are simply fixes that can be instituted on future missions.

Final images from Odysseus, lying on its side

One of three pictures downloaded after landing
Click for original picture.

In a press conference yesterday, NASA and the private company Intuitive Machines released three pictures taken by the Odysseus lunar lander after it came down a bit too fast, skidded on the ground so that one leg broke, and then tilted over.

The first images from the lunar surface are now available and showcase the orientation of the lander along with a view of the South Pole region on the Moon. Intuitive Machines believes the two actions captured in one of their images enabled Odysseus to gently lean into the lunar surface, preserving the ability to return scientific data.

The best picture, reduced and annotated to post here, is to the right. The spacecraft is tilted about 30 degrees from the vertical. Another picture showed the broken leg on the lander’s other side. The “two actions” mentioned in the NASA quote above refer to the issues that caused the broken leg: the limited ground data the lander used to land, and its larger than expected lateral speed.

The spacecraft is expected to be shut down by today because of lack of power and the advent of the long lunar night. Company officials remain hopeful it will come back to life when the sun rises in several weeks.

Officials from both NASA and Intuitive Machines have correctly noted that this was an engineering test mission, so even these failures make it a success in that the company can use them to improve the next lander. Nonetheless, it would have been nice if things had worked better on this first flight, especially because the problem that led to all the breakdowns, the failure to turn the lander’s range finding system back on after installation on the rocket, was an incredibly stupid human error that should not have happened at all.

Odysseus’ tip-over likely caused because it landed without good elevation data

It appears that the improvised switch to a NASA range finder instrument just before landing only partly worked during Odysseus’s landing attempt on the Moon, causing the spacecraft to hit the ground at too great a speed with too much laterial motion, resulting in the snapping of one leg and the lander tipping over.

Apparently, Odysseus could no longer process altitude data from the NASA instrument once it was within 15 kilometers of the surface. It had to rely on its optical cameras, a poor substitute.

By comparing imagery data frame by frame, the flight computer could determine how fast it was moving relative to the lunar surface. Knowing its initial velocity and altitude prior to initiating powered descent and using data from the inertial measurement unit (IMU) on board Odysseus, it could get a rough idea of altitude. But that only went so far. “So we’re coming down to our landing site with no altimeter,” Altemus said.

Unfortunately, as it neared the lunar surface, the lander believed it was about 100 meters higher relative to the Moon than it actually was. So instead of touching down with a vertical velocity of just 1 meter per second and no lateral movement, Odysseus was coming down three times faster and with a lateral speed of 2 meters per second.

Though the spacecraft landed upright, the high speed and sideways motion caused one leg to snap, and the spacecraft then fell over. In this sideways position Odysseus’ main solar panel could not get enough sunlight, forcing the mission to end prematurely.

A final press conference summing up the mission is scheduled for 2 pm (Eastern) today.

Was the mission a success? The failures and problems during touchdown illustrated engineering and management issues that must be addressed before the next flight. At the same time, the mission’s number one goal was to soft land on the Moon, and it did do so, even with those serious engineering problems.

More important, this flight’s first and foremost goal was an engineering test of that technology. In this sense that mission succeeded brilliantly, revealing those last technical issues.

First image from Odysseus on the lunar surface

Odysseus' view on the Moon
Click for original image.

Engineers have managed to finally download several images from Intuitive Machines’ Odysseus lunar lander, lying on its side on the Moon several hundred miles from the south pole. Five pictures were taken as the lander approached the ground. A sixth, to the right and cropped and reduced to post here, was taken after landing using a fish-eye lens. You can see two of the lander’s legs, and I think the bright spot on the horizon is the Sun.

Odysseus captured this image approximately 35 seconds after pitching over during its approach to the landing site. The camera is on the starboard aft-side of the lander in this phase.

Unfortunately, the lander’s fallen position appears to be limiting the amount of sunlight its solar panels are receiving, and thus engineers expect to shut the spacecraft down sometime today in anticipation of the lunar night. It is very doubtful Odysseus will survive that night and resume operations during the next lunar day.

Have modern space engineers forgotten the importance of keeping things simple?

SLIM on its side
The Japanese lander SLIM, on its side.
Click for original image.

In the past four years a number of different companies and nations have attempted eight times to soft land an unmanned lander on the Moon. Sadly, the track record of this new wave of lunar exploration, the first since the 1960s space race, has not been good, and might possibly suggest some basic fundamental design errors, based not so much on engineering but on our modern culture and management. To review:

  • April 11, 2019: Beresheet, built by an Israeli non-profit, failed just before touchdown when a command from the Earth caused its engines to shut down prematurely.
  • November 21, 2019: India’s government-built Vikram lander failed just before touchdown when it began to tumble and ground controllers could not regain control.
  • April 25, 2023: Hakuto-R1, built by the commercial Japanese company Ispace, failed just before touchdown when its attitude sensors mistakenly thought it had reached the surface when it was still three miles high and shut down the engines, causing it to crash.
  • August 20, 2023: Luna-25, built by Russia, crashed on the lunar surface when its engines fired for longer than planned when it began its descent, due to quality control errors during construction.
  • August 23, 2023: India’s succeeded on its second landing attempt, its Vikram lander touching down several hundred miles from the Moon’s south pole and successfully releasing its Pragyan rover. Both operated for about two weeks, until the onset of the harsh lunar night.
  • January 8, 2024: Peregrine, built by the private company Astrobotic, experienced a major fuel leak shortly after launch, making a landing attempt on the Moon impossible. It managed to operate in space for several days, reaching the distance of lunar orbit before coming back to Earth and burning up in the atmosphere.
  • January 25, 2024: SLIM, built by Japan’s space agency JAXA, successfully touched down, though it landed on its side because the nozzle on one of its engines fell off during descent, causing an unbalanced thrust. The spacecraft still functioned, and has now even survived one lunar night, something no one expected.
  • February 23, 2024: Odysseus, built by the private company Intuitive Machines, touched down somewhat softly on the Moon near the south pole, but upon landing then fell over on its side, blocking some antennas so that full communications has so far not been possible (though the spacecraft is functionable and in touch with Earth). This issue has meant that no significant data or images from the lander have so far been transmitted to Earth.

Of these eight attempts, only one mission has been entirely successful, India’s second. Of the seven others, five crashed or failed before even reaching the Moon, while two managed to soft land but with significant problems.
» Read more

SLIM survives lunar night!

SLIM's view after surviving lunar night
Click for original image.

Japan’s space agency JAXA yesterday announced in a tweet that its SLIM lunar lander had survived the harsh lunar night, and that engineers had resumed communications.

The picture to the right was taken after communications were resumed. It shows SLIM’s view of 885-foot-wide Shioli Crater, the opposite rim the bright ridge in the upper right about a thousand feet away. From this news report:

The mission team received telemetry from SLIM around 5:00 a.m. Eastern (1000 UTC). The temperature of the communication equipment was extremely high, according to JAXA, due to the sun being high over the landing area. Communication was terminated after only a short period of time, JAXA stated.

The SLIM team is however now preparing to conduct observations with SLIM’s multiband spectroscopic camera (MBC) later in the lunar day. MBC is designed to ascertain the composition of the lunar surface and could provide insights into the moon’s history. Sunset over Shioli crater, on the rim of which SLIM landed, will occur Feb. 29.

Surviving the long lunar night is a major achievement. It means Japan’s technology here is capable of doing long missions on the Moon.

LRO locates and photographs Odysseus on lunar surface

Overview map
Click for original LRO image of Odysseus

Scientists using Lunar Reconnaissance Orbiter (LRO) this weekend located and photographed Intuitive Machines’ Odysseus Nova-C lunar lander at a height of 56 miles during its first orbit over the site.

The inset in the map to the right shows the lander, with the white dot marking its landing site, several miles to the south of the planned landing site, as indicated by the yellow dot.

Odysseus came to rest at 80.13 degrees south latitude, 1.44 degrees east longitude, 8,461 feet (2,579 meters) elevation, within a degraded one-kilometer diameter crater where the local terrain is sloped at 12 degrees.

That slope could by itself explain why the lander tipped over and ended up on its side. First, it landed faster than planned. Second, Intuitive Machines designed this Nova-C lander with a relatively tall configuration, which gives it a high center of gravity. Hitting the ground fast and on such a slope could easily have been enough for momentum to tilt it over after touchdown.

Odysseus is on its side, some antennas blocked

It appears the reason communications with Intuitive Machines’ Odysseus lunar lander has been so difficult since its landing yesterdary is that something caused it to fall over so that it is now lying on its side, blocking some of its antennas.

Intuitive Machines initially believed its six-footed lander, Odysseus, was upright after Thursday’s touchdown. But CEO Steve Altemus said Friday the craft “caught a foot in the surface,” falling onto its side and, quite possibly, leaning against a rock. He said it was coming in too fast and may have snapped a leg. “So far, we have quite a bit of operational capability even though we’re tipped over,” he told reporters.

But some antennas were pointed toward the surface, limiting flight controllers’ ability to get data down, Altemus said. The antennas were stationed high on the 14-foot (4.3-meter) lander to facilitate communications at the hilly, cratered and shadowed south polar region.

Its exact location also appears to be several miles from its intended landing site next to the crater Malapart A. Scientists who operate Lunar Reconnaissance Orbiter (LRO) hope orbital images this weekend will identify the spacecraft’s precise location.

The company also revealed that the reason its own laser guidance system would not function — requiring a quick software patch allowing the spacecraft to use a different NASA system — was because “a switch was not flipped before flight.”

Because of this switch in navigation equipment it was decided to cancel the release of the student-built camera probe dubbed Eaglecam that was supposed to be released when Odysseus was about 100 feet above the surface and take images of the landing. Instead, it is now hoped it can be released post landing and get far enough away to look back and capture photos of the lander.

All these problems however do not make this mission a failure. Like Japan’s SLIM lander, the primary goal of this mission was to demonstrate the technology for softlanding an unmanned spacecraft on the Moon. Intuitive Machines has succeeded in this goal. Though obviously some changes must be made to improve this engineering, the success with Odysseus strongly suggests the next mission later this year will do far better.

Odysseus appears to have landed successfully

The privately built Odysseus lunar lander appears to have landed successfully near the south pole of the Moon, though ground controllers have not yet gotten full confirmation that all systems are functioning.

As stated by the mission director, after noting that they were getting a faint signal from the lander’s high gain antenna:

All stations, this is mission director on IM-1. We are evaluating how we can refine that signal and dial in the pointing for our dishes. What we can confirm without a doubt is that our equipment is on the surface of the Moon and we are transmitting. So congratulations IM team. We’ll see how much more we can get from that.

Shortly thereafter the company and NASA ended the live stream.

At this time they do not yet know exactly where the lander touched down, or whether it did so without damage. The signal from the high gain antenna suggests the communications system is intact as well as the antenna, but the lack of further confirmation suggests damage to other instruments, though it is also possible that the signal is not yet firm enough to obtain data from other instruments.

More updates to follow, without doubt.

Live stream of landing of Odysseus on Moon

South Pole of Moon with landing sites

UPDATE: The engineering team has decided to delay the landing attempt by one lunar orbit, pushing it back to 6:24 pm (Eastern). The live stream begins well before then, so that NASA can get in a lot of blather and propaganda, so feel safe waiting to tune in until 6 pm (Eastern).
——————-
Capitalism in space: I have embedded below the NASA live stream for the presently scheduled 5:30 pm (Eastern) landing on the Moon of Intuitive Machines Nova-C lunar lander dubbed Odysseus.

The green dot on the map to the right marks the planned landing site, about 190 miles from the Moon’s south pole. This will be the closest attempted landing so far to that pole, and if successful it will land on the rim of a crater, Malapart A, that is believed to have a permanently shadowed interior.

Odysseus however has no instruments capable of seeing into that interior. Its main mission is engineering, to test the landing technology of Intuitive Machines’ spacecraft. As part of this effort, it will release a small camera probe, dubbed EagleCam, when it is about 100 feet above the surface, which will to take images of that landing. [Update: That probe is unprecedented for another reason: It will be first student-built probe to land on another world, as it was designed and built by a team of students at Embry-Riddle Aeronautical University in Florida.]

If the landing is successful, Odysseus is designed to last until sunset on the Moon, about another two weeks. It carries a variety of NASA and commercial payloads, including a private small optical telescope. More important, it will allow the company to follow through with its manifest of future missions, including a second lunar landing later this year.
» Read more

Tomorrow’s landing of Intuitive Machine’s Odysseus lunar lander

South Pole of Moon with landing sites
Nova-C is Odysseus’s landing spot

NASA has now announced its planned live stream coverage of tomorrow’s landing attempt of Intuitive Machine’s Odysseus lunar lander near the south pole of the Moon.

Intuitive Machines is targeting no earlier than 5:49 p.m. EST Thursday, Feb. 22, to land their Odysseus lunar lander near Malapert A in the South Pole region of the Moon.

Live landing coverage will air on NASA+, NASA Television, the NASA app, and the agency’s website. NASA TV can be streamed on a variety of platforms, including social media. Coverage will include live streaming and blog updates beginning 4:15 p.m., as the landing milestones occur. Upon successful landing, Intuitive Machines and NASA will host a news conference to discuss the mission and science opportunities that lie ahead as the company begins lunar surface operations.

No live stream is of course active yet. When it goes live tomorrow afternoon I will embed the youtube broadcast here on Behind the Black.

If successful, Odysseus will be the first American landing on the Moon since the manned Apollo missions more than a half century ago. It will also mark the first successful lunar landing achieved by a privately-built spacecraft. Companies from Israel, Japan, and the U.S. have already tried and failed.

China targets May 2024 for launch of its Chang’e-6 lunar sample return mission

The Moon's far side
The Moon’s far side. Click for interactive map.

China is now working to a May 2024 launch of its Chang’e-6 lunar sample return mission to bring back about four pounds of material from the far side of the Moon.

The map to the right, created from a global mosaic of Lunar Reconnaissance Orbiter (LRO) imagery, shows the planned location of Chang’e-6’s landing site, in Apollo Basin. The landing site of China’s previous mission to the Moon’s far side, Chang’e-4 and its rover Yutu, is also shown. Both are still operating there, since landing five years ago on January 2, 2019.

Chang’e-6’s mission will be similar to China’s previous lunar sample mission, Chang’e-5, which included a lander, ascender, orbiter, and returner. It launched in November 23, 2020, landed a week later, and within two days grabbed its samples and its ascender lifted off. The samples were back on Earth by December 16, 2020.

There are indications however that Chang’e-6 might spend more time on the surface before its ascender lifts off with samples.

SpaceX successfully launches Intuitive Machines Odysseus lunar lander

South Pole of Moon with landing sites

SpaceX has successfully launched Intuitive Machines commercial Nova-C-class Odysseus lunar lander, its Falcon 9 rocket lifting off from Cape Canaveral at 1:05 am (Eastern) on February 15th.

This was the third launch in less than eleven hours today, and the second launch by SpaceX. The first stage successfully completed its 18th flight, landing back at Cape Canaveral.

The green dot on the map to the right shows the planned landing site for Odysseus, next to a crater with a permanently shadowed interior, though it will have no way to travel into it. This will also be the closest landing to the Moon’s south pole, and if all goes well, will take place eight days from today, where it will operate for about ten Earth days. You can find out more about the lander’s payloads and mission from the press kit [pdf].

It must be emphasized that like India’s Vikram lander and Pragyan rover, Japan’s SLIM lander, and Astrobotic’s Peregrine lander, Odysseus is mostly an engineering test to prove out the landing systems. If this spacecraft does any science on the lunar surface that will be a bonus.

The leaders in the 2024 launch race:

14 SpaceX
8 China
2 Iran
2 Russia

American private enterprise now leads the entire world combined 16 to 14 in successful launches, with SpaceX by itself is now tied the rest of the world combined (excluding American companies) 14 to 14.

Japan’s lunar lander shuts down for long lunar night

SLIM's last image
Click for original image.

After two days of post landing operations, engineers for the Japanese lunar lander SLIM have shut it down now as the sun has set at its landing site on the Moon and its solar panel can no longer charge its batteries.

The picture to the right, reduced to post here, was the last image sent back by SLIM before shut down. It looks to the southeast across the width of 885-foot-wide Shioli Crater, the opposite rim the bright ridge in the upper right about a thousand feet away.

The engineers shut the spacecraft down prior to sunset in order to increase the chances that it will survive that very long harsh lunar night and reactivate when the Sun rises in two weeks. They recognized that the odds of this occurring are slim (no pun intended), because the lander was not designed to withstand the night’s cold temperatures, and more important, the solar panel will not get recharged until late in the lunar day, an additional week-plus past sunrise. That long period of inactivity will likely kill it.

No matter. The spacecraft’s main goal was to prove the ability of its landing system to land softly within a small target zone. It did so, even if it had an engine issue that caused it to land upside down. This new engineering will make it possible to send unmanned and manned landers to places on other planets that previously were impossible.

Japan and India team up for unmanned lunar lander mission

Japan and India are now partnering to put a lander/rover on the Moon in 2025, dubbed LUPEX.

Set tentatively for 2025, LUPEX will be launched on JAXA’s H3 launcher, with a 350-kg rover developed by the Japanese agency. ISRO is developing the lander. The instruments will be on the lander and the rover. Initial feasibility studies and the lander’s configuration have been completed. The rover will sample the soil with a driller and the samples will be analysed using equipment on the rover,

Unlike the previously successful lunar landers from both countries (India’s Chandrayaan-3 and Japan’s SLIM), LUPEX is being designed to survive the 14-day-long lunar night, with a mission that is aiming to last three to six months.

Scientists: No obvious ice in the permanently-shadowed interior of Shackleton Crater

Shadowcam-LRO mosaic
Click for original image.

Using the low-light image produced by the American Shadowcam instrument on South Korea’s lunar orbiter Danuri, scientists now belief that there are no thick obvious deposits of water ice in in the permanently-shadowed interior of Shackleton Crater at the Moon’s south pole.

The image to the right combines pictures taken by Lunar Reconnaissance Orbiter (LRO) of the region around Shackleton with pictures produced by Shadowcam of its permanently-shadowed interior. From their paper’s conclusion:

The trailing (right) side of Shackleton’s interior is warmer owing to the secondary illumination asymmetry and floor topography. Illumination at the floor of Shackleton is patchy and possibly indicates a similar patchy (50 m scale) temperature distribution, which could mean a spatially irregular concentration of cold-trapped volatiles at the subsurface or mixed with regolith.

According to our Shackleton crater interior mapping from ShadowCam images, there is no observed evidence of thick ice deposits or surface ice that could be easily recognized by any relative brightness features observed in multiple illumination geometries. However, this analysis did not include the estimation of reflectance, nor did it involve reviewing all of the images of Shackleton in this preliminary study. Our hypothesis, in the context of water frost detections in Shackleton, is that if ice or frost is present in Shackleton’s interior, then the concentrations are either below the threshold that results in an observable signature in ShadowCam images, or might be mixed with the regolith at the detected areas. At other places where surface temperatures are below 110K, water frost could be hidden in subsurface layers.

The paper’s main purpose was to identify the dim lighting sources within the crater, all of which come from light bouncing off other surfaces. In the process the scientists obtained a better understanding of the surface itself.

China’s Chang’e-7 lunar mission will target the rim of Shackleton Crater

The Moon's south pole, with landers

China’s Chang’e-7 lunar mission, which will include an orbiter, lander, rover, and “mini-flying” probe, will land in 2026 on the rim of Shackleton Crater, one of the same candidate landing zones for NASA’s manned Artemis program.

The map to the right shows the lander’s approximate landing site, on the illuminated rim of thirteen-mile-wide Shackleton Crater at the Moon’s south pole. The candidate landing zone for NASA is also on this rim, but the location might not be precisely the same. From the abstract of the published paper [pdf] outlining the project’s science goals:

The lander will land on Shackleton crater’s illuminated rim near the lunar south pole, along with the rover and mini-flying probe. The relay satellite (named Queqiao-2) will be launched in February 2024 as an independent mission to support relay communication for ongoing scientific exploration of Chang’E-4 (CE-4), the upcoming Chang’E-6 (CE-6) in 2024, and subsequent lunar missions.

Though the abstract states the target is Shackleton’s rim, the paper is less specific, showing a map with a much wider “candidate landing region”. It is unclear if China as yet has the ability to land with the pinpoint accuracy necessary to hit the rim as stated. The paper is also devoid of any technical details about the lander, rover, or its mini-flyer. It lists the science instruments and their science goals, but describes nothing more specific. For example, will the flyer bounce or use small rockets to lift off? Or will it simply be released prior to landing with no capability of taking off again?

The big story here is the race to get to Shackleton first. NASA presently hopes its first Artemis manned mission to land on the Moon, Artemis-3, will arrive in September 2026, with its stated goal landing at or near the south pole. That schedule is certainly tentative, based on NASA’s recent track record. China is now targeting that same year, but its recent track record for its lunar program has been far more reliable.

The Outer Space Treaty forbids both countries from claiming any territory, but possession is always nine-tenths of reality. Expect China to touch down first, and hold what it touches.

Communications with SLIM lunar lander re-established

According to Japan’s space agency JAXA, engineers last night successfully re-established communications with its SLIM lunar lander sitting up-side down on the Moon, the Sun finally shifting to the western sky so that its westward-facing solar panel could get light and provide power.

Communication with SLIM was successfully established last night, and operations resumed! Science observations were immediately started with the MBC, and we obtained first light for the 10-band observation.

One image was immediately downloaded. Engineers will attempt to initiate as many operations as possible in the next few days, before the Sun sets at the end of the month and the spacecraft shuts down again, likely forever.

Lunar Reconnaissance Orbiter photographs SLIM on the Moon

LRO images showing before and after SLIM's landing
Click for blink animation.

Scientists using Lunar Reconnaissance Orbiter (LRO) were able on January 24, 2024 to obtain a photograph of the SLIM landing site on the Moon, and produce a before and after blink animation showing the lander on the ground.

The two pictures to the right, before and after, were taken from that animation. The bright speck in the after image is SLIM, sitting upside down on the surface. The faint streak of light material going from right to left lower in the photo comes from the fresh ejecta material thrown out from the nearby 1,425-foot-wide Shioli Crater to the west.

This picture confirms once again that SLIM achieved its main goal, landing precisely within a tiny landing zone only 300 feet across.

The landing occurred in the morning on the Moon, so the Sun was in the east. Because SLIM got flipped upside down just before touchdown, its one solar panel ended up facing west, where no sunlight could touch it. Based on the shadows in this picture, east is to the left, and west to the right. The solar panel is sitting in the shadow on SLIM’s right side.

In about a week the Sun will begin setting to the west, illuminating that panel. Engineers in Japan hope that at that time the panel will begin to recharge the spacecraft’s batteries, and it will then begin to operate again, if only a short while before the Sun sets and the very cold and hostile lunar night begins. There is little expectation of SLIM surviving that long two-week lunar night, even if it gets its batteries fully charged.

The shaky ground near the Moon’s south pole

Map of lunar south pole showing areas of instability
Click for original map.

According to a paper just published that reviewed and reanalyzed the seismic data gathered by the seismometers placed on the Moon by the various Apollo landings, scientists have determined that the south pole region where NASA wants its first manned Artemis lunar landing to take place happens also to be one of the Moon’s most active moonquake regions. From the paper’s conclusion:

We suggest that the lobate thrust fault scarps in the south polar region in and around the areas of the proposed Artemis III landing regions, particularly the de Gerlache Rim sites and Nobile Rim 1 regions, are potential sources for future seismic activity that could produce strong regional seismic shaking. If slip events on these young faults occur in the south polar region and elsewhere on the Moon, regolith landslides and potential boulder falls can be expected at distances of tens of kilometers from the source faults. Small amounts of water ice in the lunar regolith are expected to significantly increase the cohesion, stabilizing steep slopes against shallow landslides from seismic shaking. Based on our analysis of an N9-level event in the south polar region, we conclude that such an event poses a potential hazard to future robotic and human exploration in the region.

The map to the right is figure 10 from the paper, showing the south pole centered on Shackleton Crater. The colored dots mark areas of potential instability should a quake occur, with the blue boxes indicating all the NASA’s candidate landing sites for the manned Artemis 3 mission. Note the concentration of dots on the interior rim of Shackleton.

The planned landing site of Intuitive Machines Nova-C lander, scheduled for launch in mere weeks, is beyond the top of this map, to the north.

SLIM landed on the Moon softly, but upside down!

SLIM upside down
Click for original image.

We now know why SLIM’s solar panel was not facing the Sun after the Japanese lunar lander touched down. When it was only 10 to 15 feet above the ground, preparing to land, one of its two descent engines failed, causing the spacecraft to tumble as it softly touched down. As a result, it landed softly, but upside down, thus putting the panel on its west side instead of its east side as planned.

The image to the right, cropped to post here, was taken by one of the two tiny rovers released by SLIM just prior to landing. It shows SLIM upside down, but essentially undamaged.

The lander however still apparently achieved its primary goal, landing within a small zone only 300 feet across, or 100 meters.

Analysis of the data acquired before shutting down the power confirmed that SLIM had reached the Moon’s surface approximately 55m east (180 feet) of the original target landing site. The positional accuracy before the commencement of the obstacle avoidance maneuver (at around a 50m altitude) which indicates the pinpoint landing performance, was evaluated to be at approximately 10m or less, possibly about 3 – 4m.

…Under these circumstances, the SLIM onboard software autonomously identifies the anomaly, and while controlling the horizontal position as much as possible, SLIM continued the descent with the other engine and moved gradually towards the east. The descent velocity at the time of contact with the ground was approximately 1.4 m/s or less, which was below the design range., but conditions such as the lateral velocity and attitude were outside the design range, and this is thought to have resulted in a different attitude than planned.

In other words, when that engine failed, SLIM was only about 10 to 30 feet from its pinpoint landing target, but then drifted eastward as its dropped those last few feet because of the unbalanced engine burn caused by only one engine.

That the spacecraft is still operating and can communicate with Earth, even though it is upside down, is remarkable. Moreover, SLIM did achieve its main goals quite successfully. It landed within its tight target zone, it released two mini-rovers which operated successfully, and has been able to send its own pictures back to Earth. It was not able however to test its crushable landing legs, as they remain in the air.

Engineers shut lunar lander SLIM down in hope sunlight can recharge its batteries

SLIM's landing zone
Map showing SLIM landing zone on the Moon.
Click for interactive map.

Once they were able to download sufficient data, engineers have intentionally shut down Japan’s lunar lander SLIM in order to increase the chances it will recover should sunlight hit its solar panels and recharge its batteries.

The shutdown occurred three hours after landing on January 19, 2024, when the batteries still has a charge of about 12%.

Before turning the lander off remotely, mission control was able to receive technical and image data from its descent, and from the lunar surface. “We’re relieved and beginning to get excited after confirming a lot of data has been obtained,” JAXA said Monday in a statement, adding that “according to the telemetry data, SLIM’s solar cells are facing west”.

“If sunlight hits the Moon from the west in the future, we believe there’s a possibility of power generation, and we’re currently preparing for restoration,” it said.

The landing took place in the morning on the Moon, so there is a chance that in about a week, when the Sun shifts to the western sky, the panels will get sunlight and begin to recharge the battery.

Meanwhile, engineers confirmed that the two experimental mini-rovers were successfully deployed (see the media kit [pdf] for more details). At the moment we do not know if they have operated as planned, one rolling and the other hopping.

JAXA: SLIM soft landing successful but will likely die prematurely after landing

According to managers at Japan’s space agency JAXA, its SLIM lunar lander successfully completed its soft landing on the Moon.

It appears SLIM’s solar cells are not producing power. The spacecraft is presently on battery power, which will only last a few hours. Engineers are presently rushing to download images, taken during descent and after landing. There is also no word yet on whether the two test rovers were successfully released and achieved their test goals.

To precisely determine if the lander achieved its goal to hit a precise landing zone less than 300 feet across will require further analysis, much of which will depend on the images presently being downloaded. At the moment the engineers believe this goal was achieved, however, based on the telemetry already received.

Thus, it appears Japan has managed a soft-landing, something that in the past few years several countries (Israel, Russia, India, United States) and private companies (SpaceIL, Ispace, Astrobotic) have failed to do. Right now Japan appears to be the third nation to succeed in this new round of lunar exploration, joining China and India (which succeeded on its second attempt).

The next lunar landing attempt will be by the American private company, Intuitive Machines. Its Nova-C lander is scheduled for launch on a Falcon 9 rocket in mid-February.

SLIM lands on the Moon

Telemetry after SLIM's landing

According to telemetry data (as shown on the screen capture to the right), Japan’s SLIM lander has apparently landed on the Moon near Shioli Crater, proving its autonomous precision landing system worked as planned.

At the moment however Japan’s space agency JAXA has not yet confirmed that the landing was completely successful. After landing the announcers on the live stream repeatedly noted that though the telemetry indicated it had landed as planned, engineers had not yet confirmed that the lander was still operational. Note how the data to the right suggests the spacecraft is tilted slightly. This tilt appears to match the tilt of the surface, but it could also indicate a problem with communications.

A press conference announcing either a confirmation or a failure will begin shortly at the live stream above.

SLIM lowers orbit in preparation for January 19, 2024 lunar landing

SLIM's landing zone
Map showing SLIM landing zone on the Moon.
Click for interactive map.

The Japanese unmanned lunar lander SLIM, in orbit around the Moon since December 25, 2023, has now lowered its orbit in preparation for its lunar landing attempt, now scheduled for tomorrow, January 19, 2024, with operations beginning at 10:00 am (Eastern).

The image to the right indicates the targeted landing area near Shioli Crater. The mission’s prime engineering goal is to demonstrate precise robotic landing technology, able to land a spacecraft softly on another planet within a target zone less than 300 feet across. If successful it is expected to survive for about two weeks, studying the surface below it with a multi-spectral camera but also releasing two test probes, one a hopping rover and the second a rolling spherical rover. Both carry their own science instruments.

I have embedded the live stream for tomorrow’s landing below.
» Read more

Peregrine still operational but expected to burn up in Earth’s atmosphere

Peregrine flight path as of January 13, 2024
Click for original image.

According to an update yesterday from Astrobotic’s engineering team, the damaged lunar lander is likely to enter the atmosphere burn up when its orbit brings it back to Earth in about a week.

In an update the day before, the company released a graph of the spacecraft’s position in relation to the Earth and Moon, shown to the right. From that update:

Peregrine remains operational at about 238,000 miles from Earth, which means that we have reached lunar distance! As we posted in Update #10, the Moon is not where the spacecraft is now (see graphic). Our original trajectory had us arriving at the Moon on day 15 post launch. Our propellant estimates currently have us running out of fuel before this 15-day mark

The plan had apparently been to circle the Earth twice in this elongated orbit, with the second orbit (after some mid-course corrections) bringing Peregrine close enough to the Moon (after it had moved further in its orbit) to be captured by its sphere of influence. With the loss of fuel due to the leak, the spacecraft doesn’t have the fuel to do any of the required engine burns, including one that would avoid the Earth’s atmosphere upon return.

Update on Astrobotic’s Peregrine lunar lander

The expected flight path of Peregrine
Click for original image.

The company Astrobotic has released several more updates on the status of its Peregrine lunar lander, which will no longer attempt a lunar landing because of a major fuel leak.

The map to the right shows its expected path in the coming days. While sent in a very elongated Earth orbit by ULA’s Vulcan rocket, the spacecraft was unable to do the additional engine burns that would have put it on the correct path to reach the Moon. Instead, it will fall back towards Earth, though its fate beyond that is unclear at this time.

Meanwhile, engineers have succeeded in getting data from all payloads designed to communicate back to Earth.

We have successfully received data from all 9 payloads designed to communicate with the lander. All 10 payloads requiring power have received it, while the remaining 10 payloads aboard the spacecraft are passive. These payloads have now been able to prove operational capability in space and payload teams are analyzing the impact of this development now.

Engineers have also been able to get the spacecraft to send back a number of images. These successes help the company prove out some of the spacecraft’s systems, though it is unable to test the mission’s prime goal, landing on the Moon.

Peregrine only has hours left, its fuel leaking away

According to a number of recent updates by Astrobotic, its Peregrine lunar lander only only a few more hours of life left, its fuel leaking away due to the failure of a valve to close inside its oxygen tank.

Astrobotic’s current hypothesis about the Peregrine spacecraft’s propulsion anomaly is that a valve between the helium pressurant and the oxidizer failed to reseal after actuation during initialization. This led to a rush of high pressure helium that spiked the pressure in the oxidizer tank beyond its operating limit and subsequently ruptured the tank.

The company also noted that the Vulcan rocket did no harm to the spacecraft during launch, placing it in the correct orbit. The tank rupture however means it will not land on the Moon, and in fact is likely not going to escape Earth orbit. Sometime in the next day or so the spacecraft will run out of fuel, and at that point it will be fly out of control, its batteries draining because the solar panels will no longer point to the Sun.

How this failure will impact Astrobotic’s next and larger lander, Griffin, remains unknown. It is presently scheduled to land on the Moon in November 2024.

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