SLIM, Small Japanese lunar lander Options

[nprev]

Conference underway. Thus far:

1. Landed successfully.

2. Power-negative; battery not charging (as Hungry noticed.)

3. At least one of the little rovers landed successfully as well.

[JTN]

Press release (Japanese). Machine translation:

Results of the Small Lunar Demonstrator (SLIM) Moon Landing

 The Japan Aerospace Exploration Agency (JAXA) confirmed that the Small Lunar Module (SLIM) landed on the Moon at 0:20 am on 20 January 2024 (Japan Standard Time). Communications have been established since landing.

 However, the solar cells are not generating power, and priority is currently being given to data acquisition from the Moon's surface.

 Detailed analysis of the acquired data will be carried out in the future. We will keep you updated on the future status of the project.

[Explorer1]

Looks like the LEV 1 and LEV 2 are both working, they are getting images back now.....

[JTN]

From press conference, there is hope that even once the battery is depleted (in several hours), as the sun angle changes, the solar panels may start producing power and revive the lander. In the meantime they're prioritising getting data back over recovery operations.

(However, a couple of posts (1, 2) claim a heater has been turned off to conserve battery power -- I didn't catch this myself -- dunno what this means for the longevity of the lander.)

[Hungry4info]

I heard the comment about the battery as well. They seemed to imply that its what would allow the battery to last for "several hours."

Someone finally asked a decent question. Is there no power being generated by the solar panels? Or just an inadequate amount to keep up with the battery discharge? Answer was that they don't yet know, pending data.

[Thorsten Denk]

If I combine this picture of the landing site (downslope towards WNW)
http://www.unmannedspaceflight.com/index.p...st&id=53653
with the PV cells orientation from the loanding telemetry (towards +X; +Y is downslope),
then the PV cells should be facing north / slightly to the east (NNE).

This would mean (at 13°S) that in fact the ilumination could improve a little bit in the coming days.

(Just a very quick over-the-thumb analysis from my side, might be wrong)

Thorsten

[akuo]

Congratulations for a soft landing on the Moon.

Is restarting of the engines possible for SLIM? For an attempted hop or attitude change.

[nprev]

One thing I noticed and don't understand is that the IMU (lower left corner) was showing normal lunar surface gravitational acceleration at landing but the bar changed color from green to yellow. Don't know what the color coding indicates, but given the attitude graphic does this imply that the lander is indeed upside down?

That would explain the array not charging, but if so why are they getting telemetry unless it has a very robust omni antenna? Or maybe there's one on the ventral surface for use during cruise.

Attached thumbnail(s)

 

[Hungry4info]

From this post, it seems there's several antennas all around the spacecraft.

Attached thumbnail(s)

 

[Hungry4info]

Loss of Signal.
- from Scott Tilley,
- from AMSAT-DL.
Not sure if this genuinely means mission LOS or if it just finished transmitting something.

[mcaplinger]

One thing I noticed and don't understand is that the IMU (lower left corner) was showing normal lunar surface gravitational acceleration at landing but the bar changed color from green to yellow. Don't know what the color coding indicates, but given the attitude graphic does this imply that the lander is indeed upside down?

Presumably the lower left is the vector sum of the three accel axes and doesn't say anything about orientation, and they only display the angular rates, not the absolute angles. But one imagines they wouldn't draw it upside down if it weren't in fact oriented that way.

[kenny]

NASA's Deep Space Network is currently showing no radio traffic with SLIM. There was steady download during the first few hours after the landing.

Live feed from DSN:

Deep Space Network Tracking

This is not in any way a negative indication of the state of the spacecraft - radio traffic can be expected to stop and start.

[Phil Stooke]

I have added SLIM to my Moon map. It is here:

https://publish.uwo.ca/~pjstooke/moon-sites-map.jpg


Phil

[Thorsten Denk]

Great map, Phil!
Is there also a version including only the landers and impactors (successful and unsuccessful), but not the upper stages and orbiters?

----

Excellent 12min Video analyzing the Slim landing from Scott Manley:
https://www.youtube.com/watch?v=muK6gFtv7_o

The solar panels might point westwards.
This means that from in a week or so they might start generating power.

Thorsten

[Phil Stooke]

Thanks, Thorsten. I don't have a different version of the map.


Here's a JAXA tweet with welcome news (but no images released yet)


https://twitter.com/SLIM_JAXA/status/1749295017427108233

着陸後、電源OFFするまでの間に、着陸降下中や月面で取得した技術データや画像データの地上への送信を完了できました。現在、そのデータの詳細な解析を行っています。プロジェクトチームとしてはたくさんのデータが取得できたことを確認し、ほっとするとともにワクワクしはじめています。
#JAXA #SLIM
Translated from Japanese by
After landing, until the power was turned off, the technical data and image data acquired during the landing descent and on the lunar surface were successfully transmitted to the ground. We are currently conducting a detailed analysis of that data. As a project team, we are relieved and excited to see that we have been able to obtain a large amount of data.
#JAXA #SLIM
8:56 PM · Jan 21, 2024



From published views of the lander it appears that the multispectral camera is facing sideways as intended, and if they were able to operate it, or are able to when the sun reaches the array, it should provide good data.

Phil

EDIT:

https://twitter.com/SLIM_JAXA/status/1749320754628546849


We are preparing to announce the status of #SLIM and current results at the end of the week. Although the attitude after landing did not go as planned, we are glad we could achieved so much and are happy to have landed successfully. We’re also excited to analyse the data. #JAXA


Another point... The multispectral camera is not a panoramic camera, it will take images covering an area about 50 by 70 degrees across. But perhaps the navigation cameras are also able to take images on the surface so a partial panorama might emerge.