Chang'e 3: Lunar Day 3 and onwards, Ongoing discussion of the Rover/Lander mission Options

[Hungry4info]

The China Space facebook page reports the lander has awaken (Link).
I haven't heard anything about the rover.

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[marsbug]

I've no news I'm afraid, but I do have a question: The lander itself has instruments for UV astronomy and plasmasphere investigations. If Yutu has gone to the land of eternal crunchy lettuce, how long will the lander mission continue to run without the rover?

[Phil Stooke]

The lander was intended to last for a year. It doesn't need the rover - and the rover doesn't need the lander, it could be completely independent as they hoped it could travel several km away from the lander.

Phil

[marsbug]

Thanks Phil. It's good to know the lander is designed to run for a year. I was as much wondering if the Chinese space agency would consider the lander investigations worth the effort and money of running on their own, or if they were just a sideshow to the rover that would be kept going as part of the overall budget of rover/lander mission, but not as just a lander. Paranoia, perhaps, but sometimes these things are politically influenced and the reasons why experiments are turned off aren't always clear.

I'm going to have to uncross some things for Yutu, I'm starting to ache...…..

[MOD NOTE: Let's be careful about rule 1.2 here.]

[A.Nemo]

I've no news I'm afraid, but I do have a question: The lander itself has instruments for UV astronomy and plasmasphere investigations. If Yutu has gone to the land of eternal crunchy lettuce, how long will the lander mission continue to run without the rover?

CE-3 Lander will run one year , while china engineers had thought extended to two year

[Phil Stooke]

http://news.sohu.com/20140211/n394783771.shtml

The little video on this site doesn't tell me much but it does include some glimpses of images we have not seen before - rocks near the lander with a lower sun angle.

I have also seen a statement that there will be a news release tomorrow.

Phil

[Hungry4info]

Loss of lunar rover

China's first lunar rover, Yutu, could not be restored to full function on Monday as expected

[marsbug]

Mods: Understood.
Rest well little rabbit, may your memory be honoured by many successors.

[Cosmic Penguin]

Loss of lunar rover

Doesn't sounds like a convincing source. I think that unless Xinhua News et al. release something, we probably can't be sure that it's gone. And all the official sources are still silent (even for the lander!).......

[Cosmic Penguin]

Doesn't sounds like a convincing source. I think that unless Xinhua News et al. release something, we probably can't be sure that it's gone. And all the official sources are still silent (even for the lander!).......

And just after I wrote that there's this news claiming that the rover is showing "signs of activity" - with Xinhua News shown as the source! So maybe it's not dead? (remember that we don't even know what happened to it!)

[Yeh]

From Xinhua this morning: "Bunny seems getting better, there is evidence that he is awake, we will see." But no further details are disclosed.

http://news.sina.com.cn/c/2014-02-12/21222....shtml?wbf=more (in Chinese)

[A.Nemo]

Official Xinhuanet have gave us some good news：
http://t.qq.com/p/t/385354002655232
http://t.qq.com/p/t/362386008552526
一位正在抢救小兔子的嫦娥三号任务核心人员刚才用嘶哑的声音、兴奋的语调告诉记者：“小兔子情况趋好，有点再醒的迹象，再等等。”这是自上月25日玉兔进入月夜以来记者第一次听到积极消息。小兔子，加油！师傅们，你们辛苦了！记者余晓洁

turns well, a signs of Yutu‘s activity,Yutu begin awake？
It's first good news last from January 25，Please wait for a while

[ustrax]

"Official news: Yutu is still alive! Mission control is busy working on it. Please give more time."
https://www.facebook.com/photo.php?fbid=675...e=1&theater

[Yeh]

From my understanding of CNSA's habit, this (a very brief Xinhua news; CNSA remains silent) may mean that they got another 14 days trying to deal with the mechanical breakdown.

If they have fixed it, I don't see a reason for them to hold the news...

But anyway, the reconnection is good and encouraging. At least there are chances to solve the problem.

[marsbug]

Hurrah! Let us hope Yutu has made it through the night without too much damage. Good luck to the mission control team.

[mcaplinger]

Maybe all those ham radio operators who are complaining about the ISEE-3 situation should try listening for downlink from Yutu instead.

[Paolo]

signal from Yutu!
http://pjm.uhf-satcom.com/twtr/yutu_8462077.jpg

[Thorsten Denk]

Great!

One question, for people (like me) who are not experts
for electronics hardware at low temperatures:
What is the problem with the low temperatures?
What exactly happens, how is the electronics knocked out?
Thanks for the answers.

Thorsten

[mcaplinger]

What is the problem with the low temperatures?

Thermal expansion/contraction can break solder joints, internal bond wires, etc.
Some components (e.g., electrolytic capacitors, batteries) have goop that can freeze.

In general it's not that hard to build something that can survive Mars surface temps, but it gets colder and hotter on the Moon, so more stress.

[djellison]

Maybe all those ham radio operators who are complaining about the ISEE-3 situation should try listening for downlink from Yutu instead.

They did. With success :-O

Yup - I was surprised as well.

https://twitter.com/uhf_satcom/status/433709448717033472

[mcaplinger]

They did. With success :-O

Detecting a signal is a good deal easier than decoding it, much less generating an uplink, of course.

[Yeh]

CNSA confirmation:

http://www.weibo.com/1488228740/Awubn3MXf

官方消息：探月工程新闻发言人裴照宇昨晚表示，国产“玉兔号”月球车已全面苏醒，状态趋于好转，但是出现问题的“机构”仍然有待进一步恢复。只有苏醒了才有排故的时间，希望得到很好的救治和疗养，兔子好好休个假。

CLEP news officer Pei Zhaoyu said the Yutu rover is fully awaken and is getting better, but the mechanical problems are yet to be solved.

UPDATE: CAS official microblogger says the same thing: http://www.weibo.com/3494982177/AwufW7cDi . There is an updated news brief from Xinhua there, but says nothing relevant to the exact problem.

[Hungry4info]

From Xinhua.
China's lunar rover "awakes" despite abnormality: spokesman
"The rover stands a chance of being saved now that it is still alive,"

[elakdawalla]

This came to the Lunar Listserv from Yong-Chun Zheng:

Yesterday night, the Jade Rabbit lunar rover have sent us a good message from the Moon. In the last lunar day for the landing site, the rover met trouble to move on the surface. The control structure of the rover can't function as designed. The rabbit has gone into sleep without protection. Fortunately, our rabbit awakes yesterday with the efforts of the engineers. The instruments on the rover stood up to the challenge of the very low temperature in the lunar night. The rover can recieve the command from the ground station. We have also recieved the the data from the rover. Except some sensitive components, most of the functions of the rover have been recovered. Its experience can contribute much for all future lunar mission, both lander or rover.The lunar and planetary missions are not easy for any country. They always give us joy mingled with surprise. We anticipate the brave Jade Rabbit get new discovery on the Moon. Cheers.

[Explorer1]

It might be possible to make a visual diagnosis of the panel hinges or whatever the jammed part is, given that the lander is operational and still nearby? It all hinges on whether Yutu can drive or not, but it would take out a lot of guesswork on figuring out the issue (Galileo's high gain antenna comes to mind).

[elakdawalla]

Remember that the lander's main camera no longer works -- it failed (as expected) after the first night.

[Explorer1]

Yeah, I heard about the topography camera failure, but we know there were three others on the sides, given those great perspectives on landing day.
I was just thinking of all those other missions with mysterious failures that could have been solved or at least diagnosed by a nearby pair of eyes (or hands with a nice wrench/brush/lubricant)!

[A.Nemo]

this image from one of the TV reports has been posted on a French forum
http://www.servimg.com/image_preview.php?i...&u=17604920
I think we have never seen it before, and it looks like a perspective from late on the first lunar day

EDIT: I post the image below because I don't trust these image hosting sites...

Yutu Awake， CCTV have reported:
http://news.cntv.cn/2014/02/13/VIDE1392290645405335.shtml

Chang'e-3 have Awaked, too

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[Thorsten Denk]

Two days from now, on Sunday 23 at 22:20 UT,
will be the third sunset for the two spacecraft.

News from Yùtù have gone down to zero.
Are there maybe some chinese natives who know more?
If so, please let us know! Thank's a lot! Xièxie!

Thorsten

[Paolo]

there was a release in Chinese 2 days ago http://www.chinanews.com/mil/2014/02-19/5856563.shtml
troubleshooting continues. no more details given

[Cosmic Penguin]

Whatever it is, it looks like the "problem" is wheel/bogie related, as it turns out that Yutu was almost fully operational on the third lunar day (which it didn't move for the whole period), with the PanCam, VIRS and GPM working (I assume that the APXS is too, just that ground controllers aren't bothered with pulling its arm out): http://www.chinanews.com/mil/2014/02-23/5870836.shtml

And of course the lander's LUT and EUV imager were working as well for the whole lunar day. The lander went into hibernation for the 3rd lunar night yesterday, with the lander following several hours ago.

Here's a (new?) photo by the PanCam of the rover:

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[kenny]

I think that is indeed a 'new' photo, taken from a position South-west of the lander. My guess is it is taken from fairly close to the lander, from a position not shown on Phil's map -- in other words,
after coming round the lander Yutu perhaps made an excursion westwards which has not been noticed or recorded so far.

An alternative explanation for that view might be that it was taken in zoom mode from the 11-14 January position or later. However, I think that less plausible because of the clear view it shows of the
turning tracks made after deployment - those would be surely more foreshortened if seen in zoom from a distance.

Edit: one further thought... the shadows of the 2 deployment ramps in the 'new' photo are cast directly below the ramps, showing the sun was due south and therefore it was local midday.
The earlier post deployment photos of Chang'e from Yutu were taken well after midday, as the link below shows. Hence, the 'new' picture was perhaps taken on Day 2.

Chang'e from the south, Day 1

[dilo]

Here's a (new?) photo by the PanCam of the rover:

In this site the pictures are two, from left and right mastcam:
http://news.xinhuanet.com/english/photo/20...133136783_2.htm
Here below the crossed eye version:

[kenny]

So this status report alongside the picture, implies that Yutu could even have taken the 'new' photo on Day 3....

" This undated photo taken by the camera on the Yutu moon rover shows the Chang'e-3 moon lander and the moon surface. The Chang'e-3 lander entered its third dormancy on early Feb. 23, 2014. China's
lunar rover Yutu also entered the dormancy on Feb. 22, with the mechanical control issues that might cripple the vehicle still unresolved. According to the State Administration of Science, Technology
and Industry for National Defence (SASTIND), Yutu only carried out fixed point observations during its third lunar day, equivalent to about two weeks on Earth.
Yutu's radar, panorama camera and infrared imaging equipment are functioning normally, the control issues that have troubled the rover since January persist. (Xinhua/SASTIND) "

And the parallax on those 2 left/right photos shows they were definitely taken close the lander from the SW, at a new position.

[Explorer1]

Ah, so they did move back towards the lander after all. Whether the remaining B/W cameras can make out a visible fault is the multimillion yuan question...

[Hungry4info]

http://www.moondaily.com/reports/Is_Yutu_Stuck_999.html
http://www.spacedaily.com/reports/No_Call_for_Yutu_999.html

Some updates, with more elabouration on the technical state of the rover.

[Cosmic Penguin]

The "problem" with the rover has finally been reported: some sort of electrical problem with the motor-driving circuit board. That's still unresolved as of right now so some luck is needed again for the rover to wake up on the next lunar sunrise.

Source

[Paolo]

I can't see how a motor-driving board can put at risk the night hibernation. unless of course it also controls the retractable solar panels

[Cosmic Penguin]

I can't see how a motor-driving board can put at risk the night hibernation. unless of course it also controls the retractable solar panels

It seems that's exactly what Ye Peijian implying...

[Paolo]

yep, there is now also an English release where it is stated:

"Normal dormancy needs Yutu to fold its mast and solar panels," said Ye. "The driving unit malfunction prevented Yutu to do those actions."

[Phil Stooke]

If they can't fold one panel over the warm box, they probably can't tilt the other one down to face the rising sun (so it has to rise higher to shine on the panel and generate power). If they can't drive they may not be oriented to face that panel towards the rising sun, causing further delay.

Phil

[William Pei]

Chang'E 4 will launch this year, Ye Peijian also said: Chang'E 4 will landing a more challengeable place on the moon or even not the moon. So we may have two rabbit on the moon or another rabbit on some asteroid?

[kenny]

In that case, we may need a new thread for Chang'e 4, as we already have 5 covered.

A landing on anywhere other than the moon is a whole different game requiring extensive mission re-design.

[Phil Stooke]

I had the impression that a non-lunar option had been considered at some point in the past, but personally I would expect that the desire to demonstrate a fix for YuTu's problem would be most important now, as well as a wish to drive a much greater distance.

Phil

[Cosmic Penguin]

Chang'E 4 will launch this year, Ye Peijian also said: Chang'E 4 will landing a more challengeable place on the moon or even not the moon. So we may have two rabbit on the moon or another rabbit on some asteroid?

Are you sure? I saw 2016 mentioned elsewhere on the Chinese side.......

[Phil Stooke]

This is the new image of tracks showing my interpretation, and an alternative.

The image is a composite of two, the upper left and lower right panels of the 4-panel image put on the LROC site. The pre-landing image is used to partially subtract topography - only partially as the lighting is different. I want to emphasize tracks.

In the right half I overlay red lines: the tracks as I mapped them in the map thread, and blue lines: another possible interpretation.

Phil

[William Pei]

Are you sure? I saw 2016 mentioned elsewhere on the Chinese side.......

As a backup spaceship, Chang'E 2 was launched at next year of Chang'E 1, so Chang'E 4 will most possibly to launch at 2014, but this is depend on the progress of Longmarch-5 rocket and Wenchang space center, if Chang'E 4 decide launch at there, may be delay to 2015, but no more late than that time, because Chang'E 5 will launch at 2017 by an officilal statement.

[Thorsten Denk]

Next Sunrise in 4 hours.
Will there be again a sign of life from Yùtù?
(In two days or so of course!)

Thorsten

[Yeh]

News this morning: http://news.sina.com.cn/c/2014-03-11/033929674756.shtml (in Chinese)

Ye Peijian mentioned that a "test probe" for Chang'E 5 will be launched late this year. The probe "will not land on the Moon or take samples", "simply travel to the Moon and come back". But he did not indicate this will be Chang'E 4 or just as a separate test mission.

[Explorer1]

Sounds like a free return trajectory. Or perhaps braking into orbit and then escaping again for the challenge?

[Phil Stooke]

This is a quite separate mission, not Chang'E 4, and just intended to test the heat shield etc. for return to Earth.

Phil

[Paolo]

Sounds like a free return trajectory.

apparently it will be a Chang'e-1 bus mated to the Chang'e 5 sample return capsule injected in a free return, lunar flyby orbit. I wonder if they will envisage a secondary mission for the bus, which will remain in a high energy, C3~=0 Earth orbit unless it reenters the atmosphere together with the capsule.

[Phil Stooke]

According to this website:

http://news.163.com/14/0312/19/9N5KNCJ300014JB6.html

It seems Yutu has woken up again, thereby officially exceeding its design lifetime - if this Google translation (and my interpretation of it) is reliable:

"China news agency, Beijing, March 12 - "'Rabbit' is now in good shape, you can also expect extended service a long time." CPPCC National Committee, China Aerospace Science and Industry Group's third dean Weiyi Yin accepted in Beijing on the 12th News Agency reporter that interview.

Rabbit numbers is China's first lunar rover vehicles, the design life is three months. December 15, 2013, Chang E III lander and rover isolated rabbit numbers, "rabbit" successfully arrived on the lunar surface. 23:45 that night, the completion rabbit numbers rotate camera around Chang E on the 3rd and returns photos. Early morning of January 25 this year, Chang E III lunar rover before entering the second moonlit night sleep, the rover body control abnormal, February 10, the first rabbit No. wake fails, the night of February 12, lunar rabbit the car has been fully awake state is getting better, but the "agency" problems still need to be further recovery.

Weiyi Yin told reporters that despite the "rabbit" design life is approaching, but it is now in good shape, had been sick but wake up, long life than expected design life of many. "

[Yeh]

Phil - to me it seems Mr. Yin is just repeating what happened in Feb. It is a common practice for the delegrates to say something positive at the CPPCC, so no, I don't think he is saying Yutu's waking up.

[mcaplinger]

https://twitter.com/uhf_satcom is the most reliable source at the moment IMHO, and nothing has been seen.

[Phil Stooke]

OK, my apologies, it sounded good to me.

Phil

[A.Nemo]

Yutu alive and send signals

[Thorsten Denk]

Great!

[Liss]

Don't know if this is correct -- just reasoning.

As of Ye Peijian, the source of the partial failure of Yutu was an electrical fault in a control circuit in its driving unit which prevented folding mast, closing upper deck with the right solar panel and making correct attitude of the left solar panel.

This explanation contradicts official statements from January 25 which stated all pre-sleep actions had been conducted correctly.
And this explanation does not explain absense of any movement since January 22.
I also doubt a certain circuit is in charge for both articulating panels and powering wheel and direction control motors.

Could it be another way?

We know Yutu is very sensitive to night time attitude that should be of southern bearing and almost level roll (+1°...-2° or so) to have optimal thermal state in the morning at the moment of awaking.
If the problem appeared in the rover drive system which prevented taking this correct attitude on January 25 this naturally explains almost everything:
* absense of movement since then;
* fears of extreme cold in the night;
* late wake-up and early sleep in Lunar Day 3 vs. Day 2;
* and even the visible non-horizontality of both horizon and Chang'e 3 upper deck in the Lunar Day 3 stereo pair.

What do you think?

[Phil Stooke]

Don't think of a single circuit, think of a single circuit board... maybe?

Anyhoo... just saw an LPSC poster with a full route map on it plus topo map and reprojected photomap... more news later.

Phil

[Phil Stooke]

Revisiting the interpretation of Yutu tracks seen by LRO... this is a blow-up of the LRO image with the tracks and stops shown at LPSC. Red dots are stops between drives and blue dots are the sites of the main science activities.

The map shown at LPSC ended before Yutu drove to its final location as revealed by LRO, but not much before, as you can see.

There may be some small improvements to come, as I have seen reprojected images which fine-tune the route in the south, but basically this can be taken as nearly the final word on the route.

I will put together a more complete map later in the route map section.

Phil

[Paolo]

a short news story including the LPSC results: China's Moon rover awake but immobile

[Explorer1]

Since this seems to be the Chinese equivalent of Pathfinder/Sojourner, we should be looking forward to their MERs next time...

[Liss]

The map shown at LPSC ended before Yutu drove to its final location as revealed by LRO, but not much before, as you can see.

Nice to see the LRO tracks confirmed.

Meanwhile, in the long article http://www.chinanews.com/mil/2014/03-19/5969485.shtml they say that due to the unspecified failure some or all of the three conditions for Yutu night mode were not met before the second lunar night:

故障尚未解决，第二个月夜却要到来。当初，科研人员对月球车正常情况下进入月夜的姿态有三个设计：一是车头朝南，二是车身的左右侧倾斜在负二度到正一度之间，三是太阳翼和桅杆要收拢。“玉兔”生病后，三个条件都无法满足。

Failure is not resolved, the second Moon night has to come. At first, researchers under normal circumstances rover attitude into the moon night with three designs: first, front facing south; second, the left and right side of the body tilt between minus two degrees to plus one; third, solar wing and mast are folded. "Rabbit" after illness, three conditions are not met.

I stick to my earlier guess: Yutu lost the capability of moving between Jan 14 and Jan 21, hence couldn't met conditions (1) and (2).

[Phil Stooke]

Even if they could not move, in an effort to keep alive at all costs they would still have folded the mast and closed the folding panel if they could, so I expect that capability is also lost.


Meanwhile... trying to put together information gleaned at LPSC: the route map I referred to earlier included a dashed line extending NNE past the lander and approaching the blocky-rimmed crater just north of the lander. The author told me that was the intended path of the drive before the failure, so I think the rover was not trying to reach the lander for diagnostic purposes as some have suggested. It was simply bypassing it on the way to the next target. And the speaker on Monday said the plan after that was to loop around to the northern rim of the large crater to the west, to look into it from that direction.

That speaker was originally going to talk about route planning for the rover (the abstract and a published paper had indicated two targets for possible visits, NE and SW of the lander). But that part of the talk was dropped.

Phil

[Phil Stooke]

Another goodie from today, a speaker showed the first views I've seen from the Hazcam, looking at APXS deployment on the surface on 24 December.

Phil

[kenny]

Nice, look forward to seeing that in due course.... any views of the pyramidal rock we've all been longing to see?

[Phil Stooke]

No, none at all, but there was a clear statement that the APXS was not used on any rocks, only on regolith. I might speculate that the big rock was found to be too steep-sided (or otherwise unsuitable) for APXS placement, so they turned north to get to the northern rocky crater to find a suitable rock.

Phil

[Phil Stooke]

Another update, in case anybody had not seen this:

http://www.spaceref.com/news/viewpr.html?pid=42839

http://iloa.org/media/Astronomy%20from%20the%20Moon_314.pdf

So... more than 22000 images from the ultraviolet telescope already. ILOA will have a small telescope on the first Moon Express lander in 2015 as well, and China gets to share the use of it as ILOA gets to share the use of this Chinese telescope.

Phil

[Explorer1]

It's been two weeks and the Sun is up; no news from either component?
The eclipse is in a few days, even without pointing the cameras straight up to Earth the landscape lighting will be eerie...

[Liss]

Word is she's alive: http://www.guokr.com/post/581203/

[A.Nemo]

http://www.stdaily.com/jbsj/yb/201404/t20140417_690814.shtml
对于“嫦娥”“玉兔”来说，这次日食发生时，它们才从月夜中唤醒没多久。仿佛刚到上午，天又黑了。杨宇光说，由于探测器所处区域被地球阴影覆盖了几个小时，会出现温度骤降的情况。但“嫦娥”“玉兔”原本就是按照月昼、月夜两种极限工况设计的，应对这样的温度不会有太大问题。
此外，日食期间探测器供电系统失去了太阳能，杨宇光认为，为避免出现能源问题，可以采取不做动作、关闭科学载荷等方式降低能耗。“就好比让‘嫦娥’‘玉兔’打个盹，睡个‘回笼觉’。”他说。
据悉，“嫦娥”“玉兔”已安全度过这次考验。

after eclipse ,chang'e-3 & yutu still alive,but the news didn't comment eclipse photos

[A.Nemo]

http://tech.scichina.com:8082/sciE/CN/volu...lumn_6847.shtml
chang'e-3 special issue
another issue:
http://info.scichina.com:8084/sciF/CN/volu...lumn_6846.shtml

[Phil Stooke]

I have heard nothing, even from https://twitter.com/uhf_satcom that suggests any contact at all with the lander or the rover during the most recent lunar day.

Phil

[Paolo]

UHF Satcom is reporting detection of Yutu again! (carrier only for the moment)

[A.Nemo]

http://tech.scichina.com:8082/sciE/CN/volumn/current.shtml
Chang'E 3 special issue Ⅱ: System Design and Verification

[Paolo]

a rare update from Xinhua Chinese lunar rover alive but weak

[Paolo]

a spectrum from UHF_satcom: Yutu is downlinking data again. I am surprised by how resilient the poor rover is!
http://pjm.uhf-satcom.com/twtr/yutu_130614.jpg

[A.Nemo]

a paper have been published in copuos2014:
Chinese Lunar Exploration Program
http://www.oosa.unvienna.org/pdf/pres/copuos2014/tech-06.pdf

something about Chang'e-3：
During the day time of the first 4 months, the Lander got 118.5GB original detecting data.
Extreme ultraviolet camera:Obtained more than 600 images in total.
Lunar-based astronomical telescop:Observe the brightness and variances at near-UV band for various celestial bodies. Up till now, more than 32,000 images have been obtained.

The Patroller (Yutu) got 32GB original detecting data

current status:
The 6th moon night by May 23
The Lander is proper functioning
Patroller(Yutu) encountered control fault, part of the loading works normally
Under the abnormal condition and the extreme low temperature, the
patroller(Yutu)’s performances are gradually degenerated

[Phil Stooke]

Very nice - note that the images of the rover and crater can stand quite a bit of enlargement.

I tried to fit the picture of the big rock to this one - they don't join, and they may not be from the same location.



Phil

[Phil Stooke]

This is a list of day-night dates for Chang'E 3, from the International Lunar Observatory Association:

http://iloa.org/media/Chang'e3_Lunar_Day_Night_Cycle.pdf

They have an agreement with the mission to use some of the telescope data from the lander, in exchange for Chinese access to their data from a telescope to be delivered to the lunar south pole by Moon Express.

Phil

[charborob]

a paper have been published in copuos2014:
Chinese Lunar Exploration Program
http://www.oosa.unvienna.org/pdf/pres/copuos2014/tech-06.pdf

That document is a bit ambiguous about Chang'e 4. It is indicated in the "Roadmap", but not mentioned anywhere else. After the pages about Chang'e 3, the documents skips to Chang'e 5 (sample return in 2017). Could it mean that Chang'e 4 will not be flown?

[Phil Stooke]

I think there is some uncertainty about the role of Chang'E 4, with options including flying an upgraded lander and rover, going to a different destination (Mars, asteroid), or not flying it to focus more on the next mission. If I had any say in the matter I would try to resolve the problem experienced by Yutu and fly the rover to a different site to try to achieve a longer and more productive traverse. The continued survival of the rover despite its inability to protect its systems overnight - and the survival of the lander - shows that the overall design is excellent, and if the mobility problem could be fixed a long and productive traverse should be possible.

Phil

[Paolo]

two popular articles on Yutu on Xinhua today:
The birth of Jade Rabbit
and
Fly me to the moon

[Paolo]

and on Nature's website: China's lunar rover limps into another long night
I understand their desire to publish in Chinese peer reviewed literature, but why go for such a low impact factor publication like Research in Astronomy and Astrophysics?

[aventor.com]

I understand their desire to publish in Chinese peer reviewed literature, but why go for such a low impact factor publication like Research in Astronomy and Astrophysics?

You're assuming that Western funding mechanisms (with resulting concerns about impact metrics) apply in China.
Maybe they don't. Maybe they do science funding differently.
Chinese ties to the chosen publication (RAA) may well be more important to the Chinese.

Admittedly, I'm just speculating. I don't actually know how they do things.

[Phil Stooke]

A very interesting paper has just appeared "in press" in Planetary and Space Science:


Geological Features and evolution history of sinus Iridum, the moon
Original Research Article
In Press, Accepted Manuscript, Available online 25 June 2014
Le Qiao, Long Xiao, Jiannan Zhao, Qian Huang, Junichi Haruyama


It describes the Sinus Iridum area and identifies two landing sites for future missions, "robotic or human". Neither one is at the Chang'E 3 site.


Phil

[wildespace]

China Space page on Facebook has just posted this image from Yutu: http://www.facebook.com/photo.php?fbid=749390038455333



Not sure if this image has been posted before, or which lunar day and position it is from.

Also found this image of the large boulder, dubbed Dragon Rock: http://www.facebook.com/photo.php?fbid=737090639685273


I wonder if the brownish colouration in these images is due to camera's texhnical aspects, or is actually what the camera sees. Normalising colours in Photoshop and then enhancing saturation reveals a slightly brownish surface with bluish rocks.

[Phil Stooke]

The first of these images is the one published in that paper referred to just above (EDIT - I mean A.Nemo's post ten posts above this one). It shows the rocky wall of the crater west of the lander, probably the southern part of its western wall. It was taken from somewhere near the Dragon Rock, but it doesn't join the rock image. There are a couple of distant hills which are part of a crater rim west of the western crater.


Phil

[Phil Stooke]

Word from https://twitter.com/uhf_satcom is that Yutu is transmitting again, but no direct word yet from the lander. This is the 8th lunar day for Yutu.


Phil

[dilo]

An article with interview to Zhang Yuhua, deputy chief designer of the lunar probe system for the Chang'e-3 mission:
http://news.xinhuanet.com/english/china/20...c_133499472.htm
Based on this interview, Yutu might have been damaged by knocking against rocks on a lunar surface that is more complicated than expected from "foreign researchers" data (no comment!).

[Phil Stooke]

The latest from from https://twitter.com/uhf_satcom is that Yutu has been transmitting again in the last few days. Still alive! This was the 9th lunar day for Yutu - just ended.


Phil

[kenny]

Albeit its functionality is severely limited, it is now the second longest lived lunar rover, having exceed the 3 short-duration Apollo rovers and
Lunokhod 2, which only made it through 4 lunar days. It is creeping up on Lunokhod 1, which lasted over 11 lunar days.

[tolis]

Albeit its functionality is severely limited, it is now the second longest lived lunar rover, having exceed the 3 short-duration Apollo rovers and
Lunokhod 2, which only made it through 4 lunar days. It is creeping up on Lunokhod 1, which lasted over 11 lunar days.

yes, but one could argue that, since it has been unable to move for some time, it can no longer be considered a "rover".

[Explorer1]

Was Spirit not a rover anymore when it got stuck? I think it was!
Unless Yutu's wheels suddenly fall off it should be considered the same...

[djellison]

Was Spirit not a rover anymore when it got stuck? I think it was!

Senior management would disagree

After six years of unprecedented exploration of the Red Planet, NASA's Mars Exploration Rover Spirit no longer will be a fully mobile robot. NASA has designated the once-roving scientific explorer a stationary science platform after efforts during the past several months to free it from a sand trap have been unsuccessful.

http://www.nasa.gov/mission_pages/mer/news/mer20100126.html

[Explorer1]

Touché, but even the team members' quotes refer to Spirit as a rover when talking about its future life expectancy!
Let's leave well enough alone; we could open a can of worms like the planet definition debate....

[Phil Stooke]

When did a scientist or engineer ever take instruction from management on such a topic?

Phil

[Cosmic Penguin]

So on a different topic......there is an exhibition about Chang'e 3 (as well as the orbiters #1/2) right now at the Hong Kong Science Museum, which has some big models of the lander and rover, as well as some back up hardware of the science instruments on display. I took some photos yesterday and I shall put them up here shortly.

[Paolo]

an update in Chinese on Yutu and Chang'e 3: Yutu is about to enter its 10th lunar day and four instruments are operating normally (camera, radar, APXS, IR spectrometer).

"The lander current physical condition is very good."