Moon is the destination, the earth is my home.
Good night, earth. Good night, humanity.
1 year later, the little bunny comes with Chang'E 4, passing my body covered with lunar dust. I sigh : 'The night on the moon is really cold.' ...10 years later, his spacesuit is shinning, I am hold and raised, facing the direction to home : I am coming home!100 years later, 'Mum, is this Yutu the lunar rover? ' I lie behind the glass in museum , witnessing we make step after step into the sea of stars ...
The color camera on a stalk died. The scientific payload should last a while yet, hopefully.
What is instructive here is the Chinese are the first to attempt long duration missions on the lunar surface without first attempting short duration missions.
Quote from: SaxtonHale on 01/27/2014 10:12 pmThe color camera on a stalk died. The scientific payload should last a while yet, hopefully.Do you have more info on that failure?I was impressed by their ability to land and deploy the rover. Those are significant engineering achievements. But the problem with lifetimes is disappointing. Is there something in systems engineering that would account for this--they tested for ability but not lifetime/duration or something?Put another way, could there be an overall process failure that led to these bad things happening, something that could explain how they could be successful at the tough things, but then fail on the duration?
Quote from: SaxtonHale on 01/27/2014 10:12 pmThe color camera on a stalk died. The scientific payload should last a while yet, hopefully.Do you have more info on that failure?
UPDATE JAN 15 09:42 PT/17:42 UT: According to an unofficial Yutu rover account on Weibo (Chinese Twitter), the lander's main color camera did not survive lunar night.
The Chinese were clearly reaching on this mission. They set more challenging goals than they really needed to. For instance, a lander AND a rover. They could have just gone with the lander alone. And the lander is bigger than necessary for carrying only the rover. I don't necessarily think that's a bad thing. In fact, I admire that they took some risks and they should not be dinged for trying. But in retrospect, they might have added a step or two, such as a lander only, then lander/rover. Building two different spacecraft that operate together is not twice as hard, it is more than twice as hard because of the systems engineering challenges. They might have been straining their capabilities.
But here's a question. Why can't we simply back any spaceflight agency for doing what they did, without having to qualify it with a caveat elaborating how we would've done something differently? Especially if the comment is retrospective, and a helluva lot more so when there's either no evidence that the "different approach" (largely, and most often a different discretionary, programmatic decision, as opposed to something based on apriori, objective technical knowledge) would've definitely yielded more favourable results?
EDIT 2 - A lot of the arguments on accepting greater risk for HSF can definitely be made here. NASA probes that keep outliving their "intended" life aren't always a good thing. If your models told you that it'd switch off in 3 years, and it's still going 10 years after that, then your models clearly need to be refined. OTOH, how much of this is because the lifespans quoted are deliberately conservative (to avoid such censure in case of failure before completion of "primary" mission)?
Yutu seems to have been designed to survive two lunar nights. A test program should have subjected something like an engineering model. to some multiple of two thermal cycles to see if it survived and what failed first. Does anyone have any insight into the Chinese thermal-vacuum testing?
first presentations on CE-3 at the next Lunar and Planetary Science Congress next March http://www.hou.usra.edu/meetings/lpsc2014/pdf/sess622.pdfjust preliminary analyses, which is not too surprising since the probe landed just one month and half ago, but who said the Chinese were not going to share their results?
The Chinese were clearly reaching on this mission. They set more challenging goals than they really needed to. For instance, a lander AND a rover. They could have just gone with the lander alone. And the lander is bigger than necessary for carrying only the rover.
Quote from: Blackstar on 01/28/2014 09:35 pmThe Chinese were clearly reaching on this mission. They set more challenging goals than they really needed to. For instance, a lander AND a rover. They could have just gone with the lander alone. And the lander is bigger than necessary for carrying only the rover. I guess this means they intend to do more with the same lander design, more or less?