Author Topic: LIVE: Chang'e-3 lunar probe and rover Lunar Landing December 14, 2013  (Read 457183 times)

Offline plutogno

  • Full Member
  • ****
  • Posts: 717
  • Toulouse, France and Milan, Italy
  • Liked: 113
  • Likes Given: 6
Presentations at LPSC on Chang'e-3.

thanks! I spot a few previously unseen pictures from Yutu...

Offline plutogno

  • Full Member
  • ****
  • Posts: 717
  • Toulouse, France and Milan, Italy
  • Liked: 113
  • Likes Given: 6
in the latest issue of the Chinese Journal of Space Science: Chang’E-3 Lander’s scientific payloads
the full paper is not yet available, but it should be in a few days

full paper (in Chinese) now available. looks very interesting

Offline Liss

  • Full Member
  • ****
  • Posts: 905
  • Moscow, Russia
  • Liked: 108
  • Likes Given: 8
Well, 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:

Quote
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.

My guess remains the same as early: Yutu lost the capability of moving somewhen between Jan 14 and Jan 21, hence couldn't met conditions (1) and (2).
« Last Edit: 03/20/2014 11:26 AM by Liss »
This message reflects my personal opinion based on open sources of information.

Offline Apollo-phill

  • Full Member
  • ****
  • Posts: 454
  • UK
  • Liked: 67
  • Likes Given: 6
My understanding of some information from the  http://www.chinanews.com/mil/2014/03-19/5969485.shtml  Chinese article is as follows (edited with some paraphrasing ):-

The National Defense Science and Industry Bureau and the General Armament Department rover troubleshooting leadership attaches great importance to the work and the strong support of the "company" (programme organisation I assume ) from top to bottom . Ray Fanpei general manager, deputy general manager Yuan Jie had a special trip to SkyCity Party leadership, gave command to deploy the work, and to keep an eye on the latest progress of the work; headquarters aerospace department, model development units, Chang E III test flight control teams and expert groups have been organized together quickly, with the front and rear for fault location advice.

[Other names mentioned in article are probe deputy chief , Yang Jia ,

 The Emergency test team developed a series of troubleshooting options, including some unconventional mode of operation, and accordingly a large number of ground verification, and in a very short time to modify or even reprogramming the   software to adjust the status is set in case the point of failure state change occurs (again)

It appears the Emergency team came up with three possible solutions for Yutu (Rabbit) to try and survive the second period of lunar darkness :-

1) front facing south
2) left and right side of body tilted first (?) to negative then (?) to positive alignment
3) folded solar wings and mast

However, it seems none of these conditions were (able to be ? ) met in time before Yutu would enter the  second lunar night.

Therefore , a lot of ground analysis took place with computer programmes working out solar elevation angles for different time point and different solar wing angles to predict the possible lunar temperatures. For each scenario  the test team developed contingency measures for most reliable solution . ( I get the impression these conditions were relayed
to Yutu before  it entered the lunar night)

whilst Yutu enduring lunar night, the Emergency Teams were  working on providing  remedies  for faults  to provide to Yutu when it re-emerged into lunar day.  They formulated a series of
plans for when/if Yutu  responded. (They noted that solar wing cannot be closed and Yutu has no  (thermal ? ) blanket and cannot survive minus 150 C for long.

When Yutu re-emerged into lunar daylight  on 12th February, they only received one  carrier signal and no telemetry data . However, they followed a predetermined wakeup program , step by step,  with such steps as "frequency lock", "uplink command issue", " receive real-time telemetry ", "power good" , "temperature normal "...and so on.

However,Yutu was stationary at this stage and though its  payload devices worked properly the antenna was not able to move and therefore data could not be transmitted directly to Earth ground stations. However, it appears that designers had planned for such a anomaly by using a WiFi-UHF band transmission  from Yutu to Change'3lander which would transmit the data to Earth. It appears that the distance between Yutu and Change'3 was less than 20 metres - less than the design distance. As a consequence, they were concerned that if the number of transmissions was too many, then the UHF band equipment may have "burned out". However, they had built-in large design margins and,as consequence, they received Yutu data.

Before the abnormal situation arose with Yutu it had traversed about 100 metres.  Its four  back body science instruments - panoramic camera, measured monthly radar, infrared imaging spectrometer and particle induced X-ray spectrometer - had collected a lot of useful scientific data. including a 360-degree panorama , radar probe to within 140 meters and 10 meters below the lunar surface shallow structure , Infrared Imaging Spectrometer of the visible lunar soil, shortwave infrared spectral image data and the  particle induced X-ray spectrometry of  lunar surface elements with the detection and identification of magnesium, aluminium, silicon, potassium, strontium, yttrium , zirconium and other 11 kinds of elements .

It appears that the Chinese hold preliminary  "Controller (Masters) " classes of around one hour each class    where team members discuss issues and suggest solutions .For instance, such a "brainstorming" in each class takes place   before the Change III team thematic or technical analysis Coordination meeting is staged.

As a forward plan Controllers will make use of existing unconventional situations and harsh environments to gather more engineering data, as a means of "accumulating more valuable engineering data for future space-based research."

At 6:42 on March 14, 2014, ushered in the first four months of Yutu (Rabbit). In accordance with the work plan and related procedures, it will be transferred to the long-term management mode of the lunar rover.


Apollo-phill



















Offline Apollo-phill

  • Full Member
  • ****
  • Posts: 454
  • UK
  • Liked: 67
  • Likes Given: 6
Any updates on Change;3 and Yutu ?

Oh China,China,China - you can do much much better on news updates on your space programme -good or bad news.

We mere mortals know its difficult to get things working successfully on the Moon (or elsewhere extra terrestially) so we will not think any worse of you if there are problems on some projects. In fact, who knows, we may be able help with advice etcetera ?

So,please, issue news more regularly :-))


A-P

Offline Apollo-phill

  • Full Member
  • ****
  • Posts: 454
  • UK
  • Liked: 67
  • Likes Given: 6
 Change'3/Yutu area will not   be sunlit again until 9th April 2014.


A-P

Offline Blackstar

  • Veteran
  • Senior Member
  • *****
  • Posts: 10842
  • Liked: 2345
  • Likes Given: 1
Some neat new images of Chang'e-3 and Yutu testing that were posted to the China Space Facebook page.

Offline jumpjack

  • Full Member
  • **
  • Posts: 245
  • rome-italy
  • Liked: 1
  • Likes Given: 0


China's moon rover, Yutu, or Jade Rabbit, has already passed its design life-span of three months after landing on the moon last December, the Chengdu Business Daily reports.

Yu Dengyun, deputy chief engineer of the Chinese Lunar Exploration Program, said Tuesday that, although Yutu cannot move due to unresolved mechanical problems, it has not lost its  [...snip...]

http://english.cri.cn/6909/2014/04/02/2361s820168.htm
-- Jumpjack --

Offline Apollo-phill

  • Full Member
  • ****
  • Posts: 454
  • UK
  • Liked: 67
  • Likes Given: 6
Its Change-3/Yutu "wake-up" time again.

Waiting see if Chinese release any information about regaining contact etcetera.

A-P

Offline Lsquirrel

  • Member
  • Posts: 83
  • Liked: 27
  • Likes Given: 3
First official yutu route map!

Offline AJA

  • Full Member
  • ****
  • Posts: 855
  • Per Aspera Ad Ares, Per Aspera Ad Astra
  • India
  • Liked: 135
  • Likes Given: 202
Phil Stooke's summary at The Planetary Society Blog.

Quote
...
But the rover did not arrive at the crater, or even reach the lander. It stopped as it was getting close to the lander, apparently because the electronics associated with moving its wheels and solar panels, so probably an important central control unit, failed at that point.
...
At any rate, it soon became apparent that the rover could neither move nor fold itself up to protect against the cold of the night.
...
After a seemingly interminable wait the sun rose again, and a few days later on 12 February both lander and rover woke up. Yutu was more robust than expected. All its instruments, even the fragile cameras, were fine, but it couldn’t move. I don’t know if the lack of movement extends to the robotic arm with the APXS.
...
The rover shut down near sunset on 23 February and woke up again on 13 March, three days after sunrise, but this time much more feebly. Nevertheless, intervention from Earth, I think in the form of a computer re-boot, again restored full operation.

...
Yu Dengyun, deputy chief engineer of the Chinese Lunar Exploration Program, said Tuesday that, although Yutu cannot move due to unresolved mechanical problems, it has not lost its  [...snip...]

http://english.cri.cn/6909/2014/04/02/2361s820168.htm

So the electronic system problems were sorted out with the reboot, but the rover has a mechanical problem that prevents it from moving?

From the same CRI article

Quote
Yutu started its fourth dormancy on March 24. It's supposed to wake up around April 10 of this year.
However, Yu pointed out that it might need more resting time, since the rover cannot adjust its solar array to collect enough solar electric power quickly.
« Last Edit: 04/14/2014 09:14 AM by AJA »

Offline Liss

  • Full Member
  • ****
  • Posts: 905
  • Moscow, Russia
  • Liked: 108
  • Likes Given: 8
This message reflects my personal opinion based on open sources of information.

Offline Apollo-phill

  • Full Member
  • ****
  • Posts: 454
  • UK
  • Liked: 67
  • Likes Given: 6
Yutu alive ?

I'd like see more proof of that other than a vague reference to today's lunar eclipse from some ground based operator typing the message.

And the route map ?

Could have been produced many weeks ago as I can see no date on it .


A-P

Offline Liss

  • Full Member
  • ****
  • Posts: 905
  • Moscow, Russia
  • Liked: 108
  • Likes Given: 8
The map ends in the second lunar day, i.e. January 2014. It's evident from numbering of points.
This message reflects my personal opinion based on open sources of information.

Offline Apollo-phill

  • Full Member
  • ****
  • Posts: 454
  • UK
  • Liked: 67
  • Likes Given: 6
So map was "..weeks ago..." in January 2014. Probably produced when they thought they had a "good,working Yutu" ?

I had expected far better news release information from the Chinese than what we seem to be  getting ?

If news is being released - to their local Chinese community - that's fine  since after all their local community is paying for it ! But the same information could be released to the press outside China .  They made a good start with coverage of launch, landing and first few minutes of Yutu/Change'3 on lunar surface. But since,gone 'downhill'

So, OK they've had some bad days with various problems - some of which may still be outstanding - but let us in on it. I don't think anyone is going think "bad" of them for getting problems - the lunar environment is a  harsh operating environment . Quite the reverse if they released information on how they are dealing with the problem by ,say , carrying out software workaround rewrites, ground simulation tests and frequent pre-telemetry command meetings then,if they did this - wow, that would be great. But, not to give any real significant information (good or bad) then we can only assume that Yutu is completely "dead" and they've given up on it and maybe working toward Change'4 - a re-run? But,if they are working on Change'4 and "walking away from"  Change'3/Yutu without informing, then am I really interested and supportive of their next attempt ? No, not really, if the amount of information is going be on the same level as currently.

If humanity is going to go forward and deeper into the cosmos, we must do it as one species of human being  (as the representative  of our planet which has thousands if not millions of living creatures) . To do so, we must trust each other in interplanetary spaceflight events and we can only do that if information on interplanetary missions is shared openly.


So,please China space agency, share more information in a timely fashion -  just like you did for your launch and initial landing phase.  We - outside China - want to support you in your interplanetary endeavours.

A-P






Offline AJA

  • Full Member
  • ****
  • Posts: 855
  • Per Aspera Ad Ares, Per Aspera Ad Astra
  • India
  • Liked: 135
  • Likes Given: 202
Well, if Yutu's alive, then they'd definitely want to take some pictures of the earth during today's eclipse, and probably release them. (Provided the camera's working too).

Offline Lsquirrel

  • Member
  • Posts: 83
  • Liked: 27
  • Likes Given: 3
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。

yutu have alive,but we don't know it took pictures or not

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8333
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 5119
  • Likes Given: 3418
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。

yutu have alive,but we don't know it took pictures or not

Thanks for sharing, Lsquirrel... Google Translate gave me this

Ball shadow covering a few hours, there will be situations temperature dips. But "Chang E" "rabbit" was originally accordance May Day, Moonlight two limiting conditions designed to cope with such temperatures would not be a big problem. In addition, the system loses power during a solar eclipse solar probe, Yang Yuguang that, to avoid the energy problem, you can do to take action to close the scientific payload and other ways to reduce energy consumption. "Like Let 'Chang E'' Rabbit' nap, sleep a 'return to sleep'." He said. It is reported that, "Chang E" "rabbit" safely through this ordeal.

Perhaps someone could give a better translation?
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline plutogno

  • Full Member
  • ****
  • Posts: 717
  • Toulouse, France and Milan, Italy
  • Liked: 113
  • Likes Given: 6
and a dedicated issue of Scientia Sinica Technologica
http://tech.scichina.com:8082/sciE/CN/volumn/volumn_6847.shtml

Offline Lsquirrel

  • Member
  • Posts: 83
  • Liked: 27
  • Likes Given: 3
another dedicated issue,Scientia Sinica informationis:
http://info.scichina.com:8084/sciF/CN/volumn/volumn_6846.shtml

Tags: