Author Topic: LIVE: Chang'e-3 lunar probe and rover Lunar Landing December 14, 2013  (Read 457468 times)

Online Blackstar

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Reaching is good.  Think Apollo 8.  It would be a total waste of money to test the lander and then test the rover on a separate flight.


But there's a trade off with risk. If the lander and rover had crashed on the surface, then people would say that it was a waste of the rover to fly it without testing the lander first.

I'm not saying that's the case--it's China's space program and who am I to tell another country how to run their space program?--but these kinds of considerations exist. The Chinese approach seems to be to take fewer but larger steps, and it is possible that at some point that's going to cause them to fall down.

Offline Dalhousie

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Reaching is good.  Think Apollo 8.  It would be a total waste of money to test the lander and then test the rover on a separate flight.


But there's a trade off with risk. If the lander and rover had crashed on the surface, then people would say that it was a waste of the rover to fly it without testing the lander first.

I'm not saying that's the case--it's China's space program and who am I to tell another country how to run their space program?--but these kinds of considerations exist. The Chinese approach seems to be to take fewer but larger steps, and it is possible that at some point that's going to cause them to fall down.

Given the immense successes of the mission I don't think we can reasonably say they have fallen down.
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

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Given the immense successes of the mission I don't think we can reasonably say they have fallen down.

First, note the conditional clause "if."

Second, they didn't reach their lifetime goal.

Offline Dalhousie

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Given the immense successes of the mission I don't think we can reasonably say they have fallen down.

First, note the conditional clause "if."

Second, they didn't reach their lifetime goal.


The lander is still operating as far as we know. Only the rover may have not reached it's lifetime goal. Disapointing, but not a failure.  It has still met all the other objectives and delivered useful science. Chandrayaan did not reach its' full mission either, but is regarded as a success
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

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Given the immense successes of the mission I don't think we can reasonably say they have fallen down.

First, note the conditional clause "if."

Second, they didn't reach their lifetime goal.


The lander is still operating as far as we know. Only the rover may have not reached it's lifetime goal. Disapointing, but not a failure.  It has still met all the other objectives and delivered useful science. Chandrayaan did not reach its' full mission either, but is regarded as a success

Yeah, and I'm not arguing that, so I don't understand what your beef is.

Success is measured along a spectrum, not black/white, yes/no.

Offline Dalhousie

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Given the immense successes of the mission I don't think we can reasonably say they have fallen down.

First, note the conditional clause "if."

Second, they didn't reach their lifetime goal.


The lander is still operating as far as we know. Only the rover may have not reached it's lifetime goal. Disapointing, but not a failure.  It has still met all the other objectives and delivered useful science. Chandrayaan did not reach its' full mission either, but is regarded as a success

Yeah, and I'm not arguing that, so I don't understand what your beef is.

Success is measured along a spectrum, not black/white, yes/no.

My only "beef" (if you want to call it that) is "falling down" and "not reaching the lifetime goal" suggests a general failure.  However, as you correctly say there is a spectrum here.  Chang'e 3 has been highly successful overal.
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

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Chang'e 3 has been highly successful overal.

In terms of engineering goals (minus the lifetime of the rover).

NASA science missions tend to have level 1 and level 2 science goals. In order to be considered successful from a science perspective, they have to achieve the level 1 goals. We don't know how China measures their own science goals. It is possible that they achieved their engineering goals, but not the science goals. For instance, if a key science goal involved going to some geological feature a certain distance from the landing site and they did not do that, then they could have failed at the science goals. That's one reason why it will be interesting if the Chinese present at LPSC this year. They may offer insights into their science goals for this and future missions.

Offline jumpjack

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Harsh climate conditions are not at all the cause of yutu failure! Didn't you read the chinese "cryptic" report? The cause is the terrain.
What I understand is that, given the panels can rotate around orizontal axis, the mechanism was overstressed when yutu passed over a small crater, or when a wheel came abrubtly down back to ground after passing over a small rock.
How much delicate and inadequate are those panels for an harsh surface is visble in very first images of the rover taken from its back.
Even on a flat terrain, motors must provide much more power to rotate around orizontal axis.
Panels rotating around vertical axis would have been much better.
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Offline Dalhousie

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Harsh climate conditions are not at all the cause of yutu failure! Didn't you read the chinese "cryptic" report? The cause is the terrain.
What I understand is that, given the panels can rotate around orizontal axis, the mechanism was overstressed when yutu passed over a small crater, or when a wheel came abrubtly down back to ground after passing over a small rock.
How much delicate and inadequate are those panels for an harsh surface is visble in very first images of the rover taken from its back.
Even on a flat terrain, motors must provide much more power to rotate around orizontal axis.
Panels rotating around vertical axis would have been much better.

That's quite a statement  to make on very little data and no analysis.
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

Offline woods170

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Harsh climate conditions are not at all the cause of yutu failure! Didn't you read the chinese "cryptic" report? The cause is the terrain.
What I understand is that, given the panels can rotate around orizontal axis, the mechanism was overstressed when yutu passed over a small crater, or when a wheel came abrubtly down back to ground after passing over a small rock.
How much delicate and inadequate are those panels for an harsh surface is visble in very first images of the rover taken from its back.
Even on a flat terrain, motors must provide much more power to rotate around orizontal axis.
Panels rotating around vertical axis would have been much better.
All of this is speculation at best...

Offline Dalhousie

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Harsh climate conditions are not at all the cause of yutu failure! Didn't you read the chinese "cryptic" report? The cause is the terrain.
What I understand is that, given the panels can rotate around orizontal axis, the mechanism was overstressed when yutu passed over a small crater, or when a wheel came abrubtly down back to ground after passing over a small rock.
How much delicate and inadequate are those panels for an harsh surface is visble in very first images of the rover taken from its back.
Even on a flat terrain, motors must provide much more power to rotate around orizontal axis.
Panels rotating around vertical axis would have been much better.
All of this is speculation at best...

Not to mention that since the panels have to be horizontal you are always going to have a horizontal axis .....
"There is nobody who is a bigger fan of sending robots to Mars than me... But I believe firmly that the best, the most comprehensive, the most successful exploration will be done by humans" Steve Squyres

Offline Star One

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Sir Patrick Stewart dresses up as China's dying lunar rover, bids farewell to humanity.

http://www.theverge.com/2014/2/5/5384412/sir-patrick-stewart-dresses-up-as-chinas-dying-lunar-rover-bids

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Sir Patrick Stewart dresses up as China's dying lunar rover, bids farewell to humanity.

http://www.theverge.com/2014/2/5/5384412/sir-patrick-stewart-dresses-up-as-chinas-dying-lunar-rover-bids

I will always choose Kirk over Picard, but Patrick Stewart beats out William Shatner by a mile.

Offline JimO

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Cue 'Sunrise' in the 'Grand Canyon Suite'.

Any peeps from either vehicle?

Offline luhai167

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no news so far, very quiet.
supposedly we'll know by 2/10 14:00 when the moon is view of Chinese comm site, or 19:00 if they choose to press release on the evening news cycle and after several hours effort. If they press early, then it's probably good news, if late probably bad news, since they need to make sure the bunny is dead after poking at it for few hours.
« Last Edit: 02/09/2014 06:59 AM by luhai167 »

Offline Apollo-phill

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Yes, per luhai67, next few days will be interesting.

Mare Imbrium - Laplace F area - is now 'visible' on Moon near side.

Hope they can make comm connxns and retrieve any data to further analyse Yutu/Change'3 condition.

And, if ready and possible, upload any new commands that may alleviate or work around failed conditions.

Maybe send a "digital carrot" for "bunny" :-))

A-P



Online MATTBLAK

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Sir Patrick Stewart dresses up as China's dying lunar rover, bids farewell to humanity.

http://www.theverge.com/2014/2/5/5384412/sir-patrick-stewart-dresses-up-as-chinas-dying-lunar-rover-bids

Yeah, but I found Jon Stewart's gurning and try-hard manner too painful to watch. Even he can be funnier than that...
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Offline NovaSilisko

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Sir Patrick Stewart dresses up as China's dying lunar rover, bids farewell to humanity.

http://www.theverge.com/2014/2/5/5384412/sir-patrick-stewart-dresses-up-as-chinas-dying-lunar-rover-bids

Yeah, but I found Jon Stewart's gurning and try-hard manner too painful to watch. Even he can be funnier than that...

Agreed... I really hate this whole "lol china sucks they only did something we did 40 years ago" thing.

Offline JimO

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If the comm/controlfailure is a cold-contraction crack in a circuit board, they have been known to 'mend' when the avionics get hot and expand again. Don't bury the rabbit yet.

Offline JimO

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Two hours ago the 'China Space' Facebook page claimed a signal had been received from the lander vehicle, but nothing yet from the rover.

One comment: "Daniel Nasa Gov -- We will hopefully get back news of the rabbit after sunrise today February 10 at 15:00 hrs (3 pm), Beijing local time, and confirm whether safe or unabl [.] China has not released any official or detailed information on the cause of the malfunction or recovery actions taken by Chinese space engineers. Dust accumulation on the rover and gears may possibly be to blame for the failure to retract, based on unofficial accounts. Jade Rabbit’s unofficial Weibo account, China’s version of Twitter, has been overflowing with messages of sympathy. One user, named Amaniandlove, wrote, “You have done a great job Yutu. You have endured extreme hot and cold temperatures and show [sic] us what we have never seen. Hope you get well soon, but no matter what, it is your presence that makes [the Moon] about 390,000 kilometres away dazzling. Jade Rabbit is a hero not only for China but for the whole population of the earth. Independence that will wake up or no  I really hope that jade rabbit will wake up and we get information! Take care! Daniel Macedonia"

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