Does China have an equivalent to NASA's Deep Space Network tracking stations? By deploying large antennae in the US, Spain, and Australia, the US was able to maintain 24/7 contact with the space missions. Granted, this isn't a manned mission but I'd still think that they'd want to have continuous comms to their lander.
China lands Chang'e-4 on far side of Moon
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Re: China lands Chang'e-4 on far side of Moon
#112Earlier quoted context omitted.
The story behind Chang'e is also interesting. Essentially, she is the wife of a legendary hero, Hou Yi(后羿), who saved the mankind from dying of drought due to the presence of nine Suns, by shooting all but one of them down. Chang'e stole the Immortal Pill, and eat it alone without her husband knowing. After she ate it, her body became to float and she flied to the moon, to live there alone forever as her punishment,…
Smite fans will know all this lore as well :) Chang'e main here.
Nothing more fun than a duo Hou Yi/Chang’e lane with their respective wedding skins :)
Re: China lands Chang'e-4 on far side of Moon
#113The headline should be "China claims to successfully land..." Given the government and business tendency in China to make claims that later turn out to be fabricated nothing they announce should be taken as true without independent verification.
Re: China lands Chang'e-4 on far side of Moon
#114Does China have an equivalent to NASA's Deep Space Network tracking stations? By deploying large antennae in the US, Spain, and Australia, the US was able to maintain 24/7 contact with the space missions. Granted, this isn't a manned mission but I'd still think that they'd want to have continuous comms to their lander.
There is little value in the continuous comms to the unmanned missions. You generally want good tracking during maneuvers (which is where things go wrong), but outside of those motion is highly predictable.
And the comms to the unmanned missions are mostly for forensics (outside of active science or other active payload functions) -- if a problem arises that the automation on board cannot solve it is highly unlikely that a difference between real-time and an hour later warning would matter.
Re: China lands Chang'e-4 on far side of Moon
#115The headline should be "China claims to successfully land..." Given the government and business tendency in China to make claims that later turn out to be fabricated nothing they announce should be taken as true without independent verification.
How clever of them to have faked a rover failure with Chang'e 3 then, so that we'd believe them now if they report that the rover works. But seriously, we haven't seen any indications of the CNSA faking anything. China isn't a person, it's a whole big country. The fact that Bernie Madoff defrauded a huge number of people doesn't mean that you can't trust NASA.
Re: China lands Chang'e-4 on far side of Moon
#116pics or it didnt happen!
Re: China lands Chang'e-4 on far side of Moon
#117Earlier quoted context omitted.
The story behind Chang'e is also interesting. Essentially, she is the wife of a legendary hero, Hou Yi(后羿), who saved the mankind from dying of drought due to the presence of nine Suns, by shooting all but one of them down. Chang'e stole the Immortal Pill, and eat it alone without her husband knowing. After she ate it, her body became to float and she flied to the moon, to live there alone forever as her punishment,…
What did the rabbit do, to be punished with her :-P
The silly rabbit tried to eat the kids' Trix
Re: China lands Chang'e-4 on far side of Moon
#118Awesome. Too bad US freezes China out in working with NASA on space exploration. I think we all should partner up despite our political differences.
Do you know why NASA doesn't partner up with China? Because it sounds like you think those political differences are insignificant.
Re: China lands Chang'e-4 on far side of Moon
#119Earlier quoted context omitted.
It wasn't in TFA, but here's a source: https://www.bbc.com/news/science-environment-46724727 > The lander carries a 3kg (6.6lb) container with potato and arabidopsis plant seeds - as well as silkworm eggs - to perform biological studies. The "lunar mini biosphere" experiment was designed by 28 Chinese universities. (Source for the silkworms, at least. I must confess that giant mutant moonworms are only conjecture...…
Hm, doesn't this violate the prime directive (or planetary protection guidelines)?
The biggest reason for planetary protection guidelines is the risk of life escaping from the spacecraft and being mistaken for native life. The moon is so ridiculously inhospitable that it isn't much of a concern because no known life can survive without air or water, even before taking into account the extreme temperature swings. Somewhere like Mars or Europa has much more strict guidelines.
Also, we sent people to the Moon, which are a lot messier than silkworm eggs.
Re: China lands Chang'e-4 on far side of Moon
#120Earlier quoted context omitted.
I just wanted to add that L2 (and L1 and L3) are unstable in that if a satellite is a bit further than the exact point it will tend to get ever further with time and a satellite that's closer will tend to get even closer. But the closer you are to the exact L2 point the smaller these tendencies are and the amount of fuel needed to remain on station is minimal, a satellite will just eventually run out some day and fal…
So how can this craft orbit a point that is not a gravity well but a gravity hill, so to speak?
It's a gravity saddle! From Earth's perspective it's a hill in the r direction but a well in the phi/theta directions. To orbit at a location always visible from Earth it needs to move in the phi/theta directions but moving the the r direction doesn't help, so it doesn't.