Tag: SLIM

JAXA finally shuts down SLIM operations after four months of no contact

9:14 am

SLIM's last image
Click for original image.

Japan’s space agency JAXA today announced that it has now closed down all further attempts to contact its SLIM lunar lander on the surface of the Moon.

The Japan Aerospace Exploration Agency (JAXA) concluded operations of the Smart Lander for Investigating Moon (SLIM) on the lunar surface at 22:40 (JST), on August 23, after being unable to establish communication with the spacecraft during the operational periods from May to July*, following the last contact on April 28, 2024.

SLIM was launched onboard the H-IIA Launch Vehicle No.47 (H-IIA F47) on September 7, 2023 from the Tanegashima Space Center and achieved Japan’s first Moon soft landing on January 20, 2024. The landing precision was evaluated with a position error of approximately 10 meters from the target point, confirming the world’s first successful pinpoint landing. In addition, the Multi-Band Camera (MBC) successfully performed spectral observations in 10 wavelength bands on 10 rocks, exceeding initial expectations. Further, despite not being part of the original mission plan, the spacecraft was confirmed to survive three lunar nights and remained operational, demonstrating results that surpassed initial goals.

The lander’s main goal was to demonstrate the ability to do a precise robotic landing within a 100 meter landing zone. And even though one nozzle fell off during landing, resulting in SLIM landing on its side, it accomplished that goal and then survived three lunar nights, exceeding significantly its expected ability to function in harsh lunar environment.

The image to the right, reduced to post here, was taken by SLIM just before it was shut down for its first lunar night. 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.

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SLIM goes dark

9:14 am

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

The Japanese lunar lander SLIM has failed to respond to ground commands sent soon after dawn, ending the lander’s fourth night on the Moon.

SLIM was never expected to survive the harsh conditions of even a single 14-day-long lunar night after landing on the Moon in January 2024. Its primary mission had been to test precision autonomous landings, which it did successfully (though it landed on its side when one nozzle fell off just before touchdown). Yet, it then survived three lunar nights, resuming communications at dawn.

Its failure now is therefore no surprise, and actually marks a magnificent engineering success. The spacecraft’s hardware was proven robust enough to survive the very cold temperatures during lunar night, and suggests that future Japanese lunar landers using SLIM designs will function as well.

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SLIM survives its third lunar night

9:07 am

Though it was primarily designed to prove its landing system and was never expected to resume operations after enduring the long 14-day-long lunar night, Japan’s SLIM lunar lander has successfully survived its third lunar night, resuming contact with Earth yesterday.

JAXA said on the social media platform X that SLIM’s key functions are still working despite repeated harsh cycles of temperature changes. The agency said it plans to closely monitor the lander’s deterioration.

While the newly downloaded data and photos have some scientific value, the important data is the spacecraft’s engineering status. Finding out what continues to work and what fails after each lunar night will inform engineers on what to do best to build future lunar landers and rovers.

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SLIM survives its second lunar night, re-establishes contact

9:33 am

SLIM's view after surviving its 2nd night on the Moon
Click for original image.

According to Japan’s space agency JAXA, the SLIM lunar lander has successfully survived its long night on the Moon, re-establishiing contact with ground controllers yesterday.

Last night, we received a response from #SLIM, confirming that the spacecraft made it through the lunar night for the second time! Since the sun was still high and the equipment was still hot, we only took some shots of the usual scenery with the navigation camera

One of those pictures is to the right, reduced slightly to post here. It looks west across the floor of Shioli Crater, with the far rim about a thousand feet away. The picture is identical to previous images, tilted because the spacecraft landed on its side and has limited scientific capabilities, being primarily an engineering test mission.

That this engineering test has now survived two lunar nights speaks well for its design. It tells us that future Japanese lunar landers (and rovers) will have a good chance of surviving for a long time on the Moon.

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SLIM put back to sleep for second lunar night

3:51 pm

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.

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SLIM survives lunar night!

9:33 am

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.

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Japan’s lunar lander shuts down for long lunar night

9:15 am

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.

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Communications with SLIM lunar lander re-established

9:29 am

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.

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Lunar Reconnaissance Orbiter photographs SLIM on the Moon

1:16 pm

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.

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SLIM landed on the Moon softly, but upside down!

9:41 am

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.

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

8:54 am

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.

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

10:40 am

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.

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SLIM lands on the Moon

9:00 am

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.

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

9:33 am

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

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Japan’s SLIM lunar lander releases its first pictures of Moon

9:50 am

Oblique view of Moon by SLIM
Oblique view of the Moon, as seen by SLIM.
Click for original image.

Japan’s space agency JAXA today released the first pictures taken of the Moon by its SLIM lunar lander after entering lunar orbit on December 25, 2023.

Three images were included in the tweet. The one to the right, reduced to post here, gives an oblique view of the Moon, including its horizon. None of the images are of great scientific value, but all are very significant in terms of SLIM’s engineering. They prove the spacecraft is operating as designed, able to orient itself precisely as well as point its camera correctly. These facts bode well for the precision landing attempt, which is SLIM’s main purpose, now targeting January 24, 2024. The primary goal is to demonstrate the ability for an unmanned spacecraft to land autonomously within a tiny landing zone only 300 feet across.

If SLIM succeeds, it will then hopefully operate for one lunar day, about two weeks. It is not expected to survive the lunar night that follows.

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Japan’s SLIM lunar lander enters orbit around Moon

3:01 pm

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

After almost four months of orbital maneuvers since its launch on September 7, 2023, Japan’s SLIM lunar lander entered lunar orbit today, with a targeted landing date of January 20, 2024.

The landing site is indicated by the map to the right near Shioli Crater. SLIM is mostly an engineering test mission, with its primary goal to test an autonomous unmanned landing system capable of putting a lander down within a small target zone of less than 300 feet across. It has some science instruments on board, but any data obtained from them will be an added bonus, since the lander is only designed to operate for about two weeks, during the first lunar day. It is not expected to survive the two-week long lunar night to follow.

Because of launch delays for both of the American landers, Intuitive Machine’s Nova-C and Astrobotic’s Peregrine, SLIM will make its attempt first.

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SLIM leaves Earth orbit and is on its way to the Moon

8:51 am

SLIM's planned route to the Moon

The Japanese lunar lander SLIM fired its engines on September 30, 2023 to begin its journey to the Moon. The map to the right indicates the planned route after this trans-lunar injection burn, first flying past the Moon to put it on a trajectory that will bring it back to the Moon at the proper speed and direction for its landing several months hence.

The main goal of this mission is engineering, to test the ability of an autonomous unmanned spacecraft to land precisely within a small target zone about 300 feet across. If proven, this ability will make it possible to send unmanned landers to many places that are presently impossible due to their rough topography.

The route that SLIM is taking to the Moon is also unusual, and is probably also an engineering test of its own. Flybys of planets to change a spacecraft’s path is not a new technique, but in the past it has been used to slingshot the probe to another object, not send it back to that planet.

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Japan successfully launches XRISM X-ray space telescope and SLIM lunar lander

4:57 pm

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

Japan today (September 7th in Japan) successfully used its H-2A rocket to place both the XRISM X-ray space telescope and SLIM lunar lander into orbit.

As of posting XRISM has been successfully deployed. SLIM has not, as it needs to wait until after a second burn of the rocket’s upper stage about 40 minutes later. The map to the right shows SLIM’s landing target on the Moon, where it will attempt a precision landing within a zone about 300 feet across.

This was Japan’s second launch this year, so it does not get included in the leader board for the 2023 launch race:

62 SpaceX
39 China
12 Russia
7 Rocket Lab
7 India

In the national rankings, American private enterprise still leads China in successful launches 71 to 39. It also still leads the entire world combined, 71 to 64, while SpaceX by itself now trails the rest of the world (excluding American companies) only 62 to 64.

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JAXA schedules last H-2A rocket launch, carrying X-Ray telescope and lunar lander

9:06 am

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

Japan’s space agency JAXA today announced that it has finally rescheduled the launch of its XRISM X-Ray telescope and its SLIM lunar lander launch for September 7, 2023, lifting off using the last flight of its H-2A rocket.

The previous launch attempt several weeks ago was scrubbed due to high winds. This new launch date has a window of seven days, which means if weather scrubs the September 7th launch they will be able to try again immediately within that window.

The white dot on the map to the right shows the targeted landing site of SLIM, which is testing the ability of an unmanned probe to land precisely within a tiny zone of less than 300 feet across.

Meanwhile, with the retirement of the H-2A rocket and its replacement having not yet flown successfully (its first launch failed in March), Japan after this launch will be in the same boat as Europe, without a large rocket and lacking the ability to put large payloads into orbit.

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JAXA scrubs launch of X-Ray telescope & SLIM lunar lander due to high winds

8:57 am

SLIM's landing zone
Click for interactive map.

Because of high winds, Japan’s space agency JAXA yesterday scrubbed the last launch of its H2A rocket, carrying the XRISM X-Ray telescope and the SLIM lunar lander.

A nice description of both payloads can be found here. XRISM is a simplified reflight of the Hitomi X-Ray telescope that failed immediately after launch in 2016.

Though SLIM carries a camera and two secondary payloads, both designed to hop along on the surface and obtain some data, its main mission is engineering, testing whether a robotic spacecraft can achieve a precision landing with a target zone of 100 meters, or 310 feet. The map to the right shows SLIM’s landing site, with the white dot in the close-up inset a rough approximation of that entire target zone. If successful this technology will make it possible to put unmanned planetary probes in places previously thought too dangerous or rough.

All three craft are designed to operate for only about fourteen days, during the daylight hours of the 28-Earth-day-long lunar day.

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