Author Topic: Chang'e-4 lunar operations  (Read 68858 times)

Offline whiztech

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Re: Chang'e-4 lunar operations
« Reply #180 on: 01/03/2019 02:12 pm »
Quote
The lunar rover for China's Chang'e-4 probe was given the name "Yutu-2" (jade rabbit) after making a soft-landing on the far side of the Moon on Thursday, said China's National Space Administration.

https://www.facebook.com/ChinaGlobalTVNetwork/photos/a.566725090034982/2776574232383379/?type=3&theater

edit:

twitter link

https://twitter.com/CGTNOfficial/status/1080839206207840256
« Last Edit: 01/03/2019 02:13 pm by whiztech »

Offline Apollo-phill

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Re: Chang'e-4 lunar operations
« Reply #181 on: 01/03/2019 02:12 pm »
If you plot - with a viewable black dot -  Surveyor 7 coordinates on a lunar map onto tracing paper , then flipover the tracing paper and view the black spot you made that " roughly - sayagain , roughly !) is where Change'4 is on farside map.

Had to devise this "cheap and nasty description" for radio interviews today so public has idea    of where von karman crater is !

And,yes,Surveyor missions are some of my favourite early mission highlights.

Phill
UK

Offline freddo411

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Re: Chang'e-4 lunar operations
« Reply #182 on: 01/03/2019 02:39 pm »
The lack of coverage - especially on CGTN - is not just frustrating it is bizzare! >:(

Their program, their coverage.

Live with it.
If you have a point to make - I'm not sure what that is... Why pick on me?! Your irritation mystifies me... (a little)

EDIT: Clarification of my remarks - The Chang'e 3 landing a few years ago was carried absolutely live in great detail. This mission was not - that's what was bizzare to me! They can certainly do what they like - they don't care what a foreigner like me thinks. But your attempted suppression of my opinion is something I would never do to you.

Why I replied to your post? Simple. You were the one displaying frustration over the (lack of) live coverage of this mission.
It is IMO not up to you (and me neither btw) to have any expectations with regards to (live) coverage of someone else's space program. Particularly when it concerns the Chinese space program.

You might remember that I similarly confronted another regular here, some years ago, when he kept complaining about ESA not releasing their images of the Ulysses mission.

Here's the thing: the world is spoiled rotten with all the public domain stuff being released by NASA. But the visitors of the NSF forums would be well advised to remember that the referenced NASA policy is actually the exception, rather than the norm.
All the other space agencies around the world are (very) much more restrictive, and much more inconsequent, about what they release (and when) to the public.


But I digress.

I too register my disappointment with delayed coverage.   It happens to a lesser extent on US missions too; note that Dawn withheld many images during it's close passes over the intriguing bright spot on Ceres.    In the US, these missions are publically funded, they are required to release their info publically, but by policy they do have an exception to embargo data for a time (presumably as a reward and leg up to the scientists working the mission).   

As a taxpayer and voter that pays for and authorizes these NASA missions I believe that we ought to be entirely transparent with all imagery by making it public as it is downloaded.   The public perception is more important than the scientists' interest in embargoing the information.   

Offline Phillip Clark

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Re: Chang'e-4 lunar operations
« Reply #183 on: 01/03/2019 02:42 pm »
It would appear that the P-R discussion is taking over this thread which should be addressing the actual mission events and science ......... ?
I've always been crazy but it's kept me from going insane - WJ.

Offline Liss

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Re: Chang'e-4 lunar operations
« Reply #184 on: 01/03/2019 03:05 pm »
https://m.weibo.cn/detail/4324507022201770

【揭晓了!月球车命名为“玉兔二号”】2018年12月8日2时23分,#中国探月工程##嫦娥四号任务# 着陆器和巡视器(月球车)组合体发射升空,2019年1月3日10时26分成功着陆月球背面,随即着陆器与巡视器分离,22点22分@月球车玉兔二号 到达月面,开始就位探测和巡视探测。@月球车玉兔 @中国探月工程

Descended to the surface at 22:22 Beijing time = 14:22 UTC.
This message reflects my personal opinion based on open sources of information.

Offline whitelancer64

Re: Chang'e-4 lunar operations
« Reply #185 on: 01/03/2019 03:07 pm »
Quote
The lunar rover for China's Chang'e-4 probe was given the name "Yutu-2" (jade rabbit) after making a soft-landing on the far side of the Moon on Thursday, said China's National Space Administration.

https://www.facebook.com/ChinaGlobalTVNetwork/photos/a.566725090034982/2776574232383379/?type=3&theater

edit:

twitter link

https://twitter.com/CGTNOfficial/status/1080839206207840256

The wheels look pretty near to identical to the first Yutu rover.
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Online Galactic Penguin SST

Re: Chang'e-4 lunar operations
« Reply #186 on: 01/03/2019 03:10 pm »
Here is Yutu 2 rolling off the ramp onto the Moon surface:

https://weibo.com/2656274875/Hai4yAj6E
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline redliox

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Re: Chang'e-4 lunar operations
« Reply #187 on: 01/03/2019 03:16 pm »
Here is Yutu 2 rolling off the ramp onto the Moon surface:

They don't seem to hesitate in deploying their vehicles like NASA.  I recall how both Sojourner and InSight didn't move for days if not weeks post-landing.  Any reason to Chinese methodology, or is it at least in the case of Yutu-2 they feel confident in their rover's design?
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Offline Star One

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Re: Chang'e-4 lunar operations
« Reply #188 on: 01/03/2019 03:18 pm »
Here is Yutu 2 rolling off the ramp onto the Moon surface:

https://weibo.com/2656274875/Hai4yAj6E

The rabbit certainly didn’t waste any time in escaping from its hutch.

Offline Phillip Clark

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Re: Chang'e-4 lunar operations
« Reply #189 on: 01/03/2019 03:37 pm »
The rabbit certainly didn’t waste any time in escaping from its hutch.

It was longer than Yutu [1] being deployed from Chang'E 3.
I've always been crazy but it's kept me from going insane - WJ.

Offline djellison

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Re: Chang'e-4 lunar operations
« Reply #190 on: 01/03/2019 03:44 pm »
I recall how both Sojourner and InSight didn't move for days if not weeks post-landing.  Any reason to Chinese methodology, or is it at least in the case of Yutu-2 they feel confident in their rover's design?

Sojourner was deployed from Pathfinder on Sol 2 - the day after landing.   

The InSight arm was first moved on Sol 4.

The operational paradigm on the Moon is quite dramatically different.  You have a LOT of bandwidth compared to a typical Mars mission, and you have near realtime commandability.  Typical Mars surface missions basically only get one uplink to the spacecraft each morning, so any 'unit' of activity ( checkouts, deployments etc ) always take at least a day each.

Moreover, on the Moon you have 2 weeks of constant sunlight pouring into your solar panels, so you can have the spacecraft basically permanently active, near realtime commanded, for 300 hours consecutively.   

Between uplink and downlink on a Mars surface asset - you typically only get about 5 or 6 hours, so 300 hours of surface ops would take more like a month or two.



Online Hungry4info3

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Re: Chang'e-4 lunar operations
« Reply #191 on: 01/03/2019 03:48 pm »
Yutu (1 and 2) are capable of operating independently of the lander. But Yutu needs the lander alive to get off of it and onto the lunar surface. From the time between landing and rover deploy, a sudden loss of the lander means loss of both missions. After the rover is out, if the lander were to suddenly fail, the rover mission is unaffected. As a result, there's probably an added pressure to deploy the rover that has not been present on any other rover missions.

Offline Star One

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Re: Chang'e-4 lunar operations
« Reply #192 on: 01/03/2019 04:13 pm »
Do we know how much Yutu 2 has been upgraded from the first one, or is it an identical copy?

Offline whitelancer64

Re: Chang'e-4 lunar operations
« Reply #193 on: 01/03/2019 04:22 pm »
Do we know how much Yutu 2 has been upgraded from the first one, or is it an identical copy?

I think the only official word is that the systems that failed on Yutu-1 were much improved on Yutu-2. At a glance, with this resolution of photo, they look identical. Yutu-2 is built from backup hardware from the Yutu-1 mission. Similar to what was done with Curiosity and Rover 2020.
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Offline zhangmdev

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Re: Chang'e-4 lunar operations
« Reply #194 on: 01/03/2019 05:03 pm »

I think that is definitely from Chang'e 3 panorama

http://news.sciencenet.cn/htmlnews/2014/3/289376.shtm

Hard to believe that was almost 5 years ago.
« Last Edit: 01/03/2019 05:04 pm by zhangmdev »

Offline mcgyver

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« Last Edit: 01/03/2019 05:30 pm by mcgyver »

Offline clongton

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Re: Chang'e-4 lunar operations
« Reply #196 on: 01/03/2019 07:47 pm »
The regolith appears more "dirt"-ier than what we've seen from the near side. I would sure love to know the composition of that "soil". BTW, how is Chang'e 4 communicating with earth? Do the Chinese have a relay communications satellite in a halo orbit around EML-2?

My sincerest congratulations to the Chinese for this accomplishment. It was well done!
« Last Edit: 01/03/2019 09:27 pm by clongton »
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Offline JimO

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Re: Chang'e-4 lunar operations
« Reply #197 on: 01/03/2019 07:50 pm »

I too register my disappointment with delayed coverage.   ….


Recall that there were several days of silence after the Toutatis flyby when some of us began to suspect a failure -- turned out it was a terrifying unintentionally too-close nearly-collided fly-by. But the pictures were sensational, another contact binary like Ultima-Thule. 

Offline Lars-J

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Re: Chang'e-4 lunar operations
« Reply #198 on: 01/03/2019 07:53 pm »
The rigoleth appears more "dirt"-ier than what we've seen from the near side. I would sure love to know the composition of that "soil". BTW, how is Chang'e 4 communicating with earth? Do the Chinese have a relay communications satellite in a halo orbit around EML-2?

My sincerest congratulations to the Chinese for this accomplishment. It was well done!

Yes, they do have a relay satellite around EML-2.

My congratulations as well! :)

Online Svetoslav

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Re: Chang'e-4 lunar operations
« Reply #199 on: 01/03/2019 07:57 pm »
Buzz Aldrin reacts to China's moon landing:

https://twitter.com/TheRealBuzz/status/1080917897768329216

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