The Chang'e 2014 Countdown Thread!

[xenomorph555]

It has come to my attention that the launch of China's Chang'e test craft is drawing near. Usually a large amount of information about Chinese missions appears in the few weeks before launch so I have created this thread a place for updates and for those who follow the Chinese moon program.

As of now the launch is rumoured to be the 24th of October however new rumours indicate a September launch.

I will continue to post updates on the mission, but of course please contribute if you have any knowledge we would all be grateful.

[xenomorph555]

Mission Profile

The aim of this mission is to test the strength of the soil return capsule on re-entry of the Earth's atmosphere from lunar distance (11.2 km/s) for the Chang'e sample return mission in 2017. The mission may also test the Chang'e 5 propulsion system although there is no proof of this.

The lunar probe consists of 2 sections, the service module which has been described as a chang'e 2 replica but modified with various other systems and possibly the experimental propulsion system although as stated this is not confirmed. The second section consists of the return capsule, a scaled down shenzhou descent capsule.

The probes will have a few scientific instruments such as radiation measuring devices as well as biological samples housed in the return capsule, these include plants and bacteria.

The probe will be launched from Xichang launch center on a Long March 3C rocket, earlier reports state it will travel to the moon on a free return trajectory however newer reports from inside China report it will enter lunar orbit and stay for up to a month to perform research, this would mean the service module has the experimental propulsion system, so far it unknown which one is correct. After departing the moon the probe would perform skip re-entry and land in Mongolia. The shortest mission time would be 9 days.

[Scotius]

Experimental propulsion module? Ion? Nuclear? EmDrive? Moar data is needed

[xenomorph555]

Experimental propulsion module? Ion? Nuclear? EmDrive? Moar data is needed

That would be pretty cool , however unfortunately it's a little less exciting. Basically a incredibly powerful and efficient chemical engine that can exit LEO, put the probe into lunar orbit and then exit lunar orbit for a trip back to Earth all the while carrying the lander. Think of it as a scaled down Apollo service module engine.

Edited September 4, 2014 by xenomorph555

[Dkmdlb]

Hypergolic?

[xenomorph555]

Hypergolic?

Storable propellants, unsure what type or if their hypergolic though.

Chang'e 3 and apollo both used UDMH and N2O2 which are storable hypergolics so it would be reasonable to use the same thing. China also uses this propellant mix in all of the Long March rockets so they have good experience.

[Streetwind]

If it's derived off of the Apollo engine, then yes, it's hypergolic. But then again, the US for some reason have this silly notion that they shouldn't talk to the Chinese about anything space related, so I'd put my money on a local design.

If it's efficient it could be a hydrolox engine. Boiloff can possibly be mitigated enough with modern technology for the few days this mission will take to enter lunar orbit and do its ejection burn. The question is though, why should they bother? A translunar injection, orbit insertion and following trans-Earth injection takes a decent amount of dV but not so much that you really have to push boundaries to make it work. They did it in the 60's on hypergolics without insane fuel mass fractions, and it's cheaper and makes the spacecraft smaller and more reliable, so I see no real reason for China to go for anything else here. Unless they really, really feel a need to test hydrolox for deep space applications.

[Kryten]

'Experimental propulsion module' sounds like it could be the 'advanced space tug' being developed for BLEO missions, mostly launches of next-gen Beidou sats. It was supposed to debut towards the end of this year, and is a hyperbolic stage basically comparable to fregat.

EDIT: or not, that only has about a seven hour design life. Xeno, are you sure the sources talking about an orbital mission are reliable and not simply based on misinterpretation?

Edited September 4, 2014 by Kryten

[xenomorph555]

If it's derived off of the Apollo engine, then yes, it's hypergolic. But then again, the US for some reason have this silly notion that they shouldn't talk to the Chinese about anything space related, so I'd put my money on a local design.

If it's efficient it could be a hydrolox engine. Boiloff can possibly be mitigated enough with modern technology for the few days this mission will take to enter lunar orbit and do its ejection burn. The question is though, why should they bother? A translunar injection, orbit insertion and following trans-Earth injection takes a decent amount of dV but not so much that you really have to push boundaries to make it work. They did it in the 60's on hypergolics without insane fuel mass fractions, and it's cheaper and makes the spacecraft smaller and more reliable, so I see no real reason for China to go for anything else here. Unless they really, really feel a need to test hydrolox for deep space applications.

Oh I never said it was derived from Apollo, I meant compare it to Apollo if anything it is most likely derived from the Chang'e 3 engine. As for the fuel I highly doubt they would use cryo's for reasons you have stated, it would be wise of them to use the tried and true hypergolic fuels.

'Experimental propulsion module' sounds like it could be the 'advanced space tug' being developed for BLEO missions, mostly launches of next-gen Beidou sats. It was supposed to debut towards the end of this year, and is a hyperbolic stage basically comparable to fregat.

EDIT: or not, that only has about a seven hour design life. Xeno, are you sure the sources talking about an orbital mission are reliable and not simply based on misinterpretation?

Ah you are talking about the Yuanzheng-1 advanced upper stage, I have been following that project for a while now. I'm afraid that the two propulsion systems are completely different, for one the YZ-1 is cryogenic and for the reasons Streetwind mentioned it is unlikely the service module would use this. I believe the YZ-1 will be used to put future probes into escape velocity though. In an unrelated note the first YZ-1 flight will be in October.

On the other topic I never stated that I believe there will be an orbital mission, personally I think there was a translation mix up, it happens a lot with Chinese articles like when they called YZ-1 a space shuttle bus... however I must accept the possibility of the orbital mission.

Edited September 4, 2014 by xenomorph555

[mrfox]

http://www.spacedaily.com/reports/China_Sends_Life_to_Moon_999.html

[xenomorph555]

Thanks for posting the article!

Also what is everyone's view on the "it's a prep for a manned mission" theory proposed by the writers of Spacedaily and many other people.

[Sky_walker]

Well, I wish them luck and hope it is what the spacedaily.com suggests.

Not because I care about them in particular, but because it might work as a driving motor for future progress of all nations.

[Ralathon]

Thanks for posting the article!

Also what is everyone's view on the "it's a prep for a manned mission" theory proposed by the writers of Spacedaily and many other people.

It might be preparation for a manned mission. But I think it's more a matter of convenience. "Hey, we need a strong and reliable capsule that can reenter the earth's atmosphere", "Just take that model we've always used and strip out the crap we don't need".

[xenomorph555]

It might be preparation for a manned mission. But I think it's more a matter of convenience. "Hey, we need a strong and reliable capsule that can reenter the earth's atmosphere", "Just take that model we've always used and strip out the crap we don't need".

I was thinking along the same lines, also to keep the workforce that makes Shenzhou's busy.

[Kryten]

China do have existing re-entry capsules of the right size; they just look nothing like Shenzhou.

[magnemoe]

China do have existing re-entry capsules of the right size; they just look nothing like Shenzhou.

The description sounds like its an film return capsule so its probably retired, remaking it might be expensive, its also not designed for a moon return who comes in faster and would also require an remake, probably better to base it on current heat shields.

[xenomorph555]

China do have existing re-entry capsules of the right size; they just look nothing like Shenzhou.

Oh yeah forgot about those, I don't think they build them any more though.

[Idobox]

Of course China is thinking about sending people to the Moon, but that doesn't mean they have a proper plan to do so.

From the article, it looks like they consider sending somebody on a Lunar orbit or some other short mission beyond LEO, and could beat USA in the race for the first human beyond LEO since Apollo. Why else would they care so much about the effects of radiation on biological samples?

Landing humans is of course something China would love to do, but it doesn't look like they're going to have the technology and resources for at least 10 years.

[Reddragon]

I wouldn't say they don't have the technology but the budget. CNSA needs a major boost to do so. They might be planning a manned moon flyby from two launches though. That in itself is a a huge step forward that could awaken other agencies as well.

[xenomorph555]

China don't need money they have the power of communism!

In all seriousness though, an extra billion yen could go a long way.

[Reddragon]

China don't need money they have the power of communism!

In all seriousness though, an extra billion yen could go a long way.

Well, considering they only get about 1.5 billion, a 2-4 billion raise is going to happen sooner or later to ramp up the manned missions. I hope sooner because CNSA is really focusing on the moon and manned spaceflight and if the two could come together it'd be amazing. I still think the reason they aren't putting in every efforts is that they know a new race to the moon could be over pretty soon if NASA gets involved or even Roscosmos. But considering the usual secretive launches and the fact that the budget can really only be estimated I could imagine some work is underway for some surprising missions soon.

[xenomorph555]

Well, considering they only get about 1.5 billion, a 2-4 billion raise is going to happen sooner or later to ramp up the manned missions. I hope sooner because CNSA is really focusing on the moon and manned spaceflight and if the two could come together it'd be amazing. I still think the reason they aren't putting in every efforts is that they know a new race to the moon could be over pretty soon if NASA gets involved or even Roscosmos. But considering the usual secretive launches and the fact that the budget can really only be estimated I could imagine some work is underway for some surprising missions soon.

I'm not to sure if they even need a budget increase, it would be nice but the Chinese appear to be very efficient and it's what allows their space program to be sustainable. I'm sure they will get some form of increase, Xi Jinping is apparently quite fond of the idea of space exploration. I too would love to see the chang'e and shenzhou programs combined.

[Reddragon]

I'm not to sure if they even need a budget increase, it would be nice but the Chinese appear to be very efficient and it's what allows their space program to be sustainable. I'm sure they will get some form of increase, Xi Jinping is apparently quite fond of the idea of space exploration. I too would love to see the chang'e and shenzhou programs combined.

Indeed, Xi Jinping seems to get it right. The cooperation with Roscosmos payed off very well, so hundreds of millions didn't have to be spent on designing a completely new hardware for Shenzhou. China as for now lacks of scientific missions beyond the chang'e program except for some plans but at least the money isn't split up into too many departments. Though I absolutely support unmanned science missions as a priority, that's why NASA 'can't afford' too bold missions from 17.5. Earth science, ISS, rover/satellite missions are eating up most of the money and they also have to build up the equipment for the new launch system with ultramodern machinery at the same time.

I found this cool facebook site for the the Chinese space program. Probably you know about it, but I thought it worth the mentioning anywas: https://www.facebook.com/ChinaSpace?fref=nf

Edited September 10, 2014 by Reddragon

[xenomorph555]

Yeah I've followed that facebook page for ages now, it's a good place to dig up info and find hard to get pictures

[Kryten]

But considering the usual secretive launches and the fact that the budget can really only be estimated I could imagine some work is underway for some surprising missions soon.

Launches can be secretive, but that's not the same as secret. I can't think of a single launch where we don't know where the payload was going or generally what it was doing.