OK people! An update from the #JAXA#SLIM team about the spacecraft have been posted on twitter (with the secret hope that y'all hush long enough to get some decent data analysis done 😅 ).
Press conference: SLIM has been communicating with Earth and is recieving commands accurately. The spacecraft is responding in a normal way. However, the solar cell is not generating electricity at this point in time. Currently using battery power.
It sounds like they're prioritizing data retrieval instead of troubleshooting the solar panels. They're going to keep trying over the next few weeks as the solar direction changes. #space#science#slim
Still no news on whether Japan's #slim#moon lander successfully touched down. Data is being received, but the overall situation is unclear, a press conference pending. Some speculate the lander might have come to rest in an unintended orientation to the surface, there's quite a slope. It used pre-landing scanning for obstacle avoidance.
Want the ultra-cool tiny moon #rover LEV-2 to succeed, one of 2 types on board! It's not larger than a child's fist: 8 cm, 250g + 2 cameras, adapts shape ...
The Japanese Space Agency's press conference has just now confirmed that the lander has successfully landed and is correctly receiving commands and sending data. But the solar panels are not producing electricity so the lander is running only on battery. It's not clear yet what the cause is, eg orientation. The two landers were said to have successfully separated from the lander but data are still being gathered for an assessment. #slim#moon
JAXA's Smart Lander for Investigating Moon (SLIM) is getting ready for landing on the lunar surface tomorrow Friday Jan 19 at 15:20 UTC.
The spacecraft, nicknamed the “Moon Sniper,” will demonstrate precision landing in a target area less than 100m in diameter, using real-time image recognition technology.
The spacecraft will land on a sloping surface near the crater Shioli.
SLIM carries a number of science instruments and will also deploy 2 rovers.
AMSAT-DL reports that the signal from SLIM stopped at 17:57 UTC (the 17:00 in the tweet below is an error which they later corrected).
DSN is not showing a signal at this time either.
Here is my simplistic take on what likely happened.
The following panels from the webcast show the orientation of SLIM near touchdown. Each panel has two views. left view looking up the slope, right view from the side.
In Panel 1, SLIM was oriented correctly and planning for a final orientation as in panel 5.
But starting in panel 2, SLIM rotated right 90° and rotated 180° vertically.
It is now lying upside down, solar panels on the side. There is likely some damage too.
Let's keep in mind that after the legs touched the sloping lunar surface, SLIM was supposed to gently tilt/rotate towards the slope.
Perhaps, the rotation started too early and the spacecraft over-rotated. Maybe, one or more thrusters failed. The sideways rotation might have been caused by the spacecraft head jamming into the surface, thrusters still firing.
This is of course very coarse analysis based on what was displayed on the webcast. JAXA will figure it all out shortly.
Assuming that the SLIM lander is near upside down on the lunar surface, which way are the solar panels facing?
One likelihood is South, in which case, they will see very little Sun, given that the Sun stays on the North side in the sky (SLIM is at latitude 13.33 S).
Facing west would be more advantageous as the Sun would light them up later in the lunar day after Jan 24.
Scott Manley in a YouTube video says that the panels are facing west, as indicated in the diagram above.
Also, around 15:19:50, according to the data shown in the webcast, all thrusters on the SLIM lander were firing at abnormally high rates and the spacecraft was rotating along all 3 axes.
The clock on the display was frozen at 15:18:50 and then jumped to 15:19:03, indicating perhaps a loss of telemetry during that interval.
Things certainly did not look healthy around touchdown time. Although, this could be a telemetry glitch.
SLIM was indeed powered down at 17:57 UTC (which is when AMSAT-DL reported loss of signal; see post #27). Battery level was 12% at that time, 2.5 hours after touchdown.
Telemetry shows that the solar panels are facing west and there is hope that later in the lunar day, the system may revive. Many of us concluded that from the webcast images.
This photograph of the JAXA SLIM spacecraft taken by the LEV-2 rover was released today. It confirms that the lander ended up upside down on the lunar surface.
A press conference is in progress which will provide more details on the anomaly that caused this issue even though SLIM achieved its goals of landing within a very tight target area and deploying the two rovers.
The tiny crawling rover LEV-2 successfully sent this image via LEV-1.
These two b/w images of the lunar surface near the landing area were taken and sent by the JAXA SLIM lander itself in spite of its unfortunate landing orientation.
The first image was taken by the CAM-PX camera. It also shows the slope of the landing area.
The 2nd image was taken by the geological survey spectroscopic camera. The 1st image is overlaid in the inset.
Both images show small rocks on the relatively smooth terrain.