Chang'e-4 lunar probe and rover - CZ-3B- XSLC - December 7, 2018 (18:23 UTC)

[beidou]

Various Chinese news sources have reported that the second launch of the Phase II of the Chinese Lunar Exploration Project - Chang'e-4 will be launched with the CZ-5 launch vehicle, which is supposed to have its maiden flight as early as in 2014. And the payload of Chang'e-4 will depend on evaluating the results of Change'e-3 mission. So it's very likely that the Chang'e-4 will be launched in 2015 or beyond.

[plutogno]

interesting. does it mean that CE4 will not be a reflight of the CE3 spacecraft? will it be substantially heavier?

[Phillip Clark]

interesting. does it mean that CE4 will not be a reflight of the CE3 spacecraft? will it be substantially heavier?

Unless they fly a very low payload mass as part of the CZ-5 development programme?   I am skeptical about Chang'e 4 flying on the CZ-5 though.

[Dalhousie]

It depends which version of the Sz 5 of course.

[Galactic Penguin SST]

Interesting news report: CE-4 will be based on CE-3 (with modifications), but its mission will only be a few months long, shorter than CE-3 (!). This, along with quotes of a possible "CE-5 risk mitigation" mission, seems to point to the possibility of replacing the CE-3 lunar rover with the prototype CE-5 ascent stage to test its ability to reach lunar orbit. The mission should be wrapped up by 2017.

<speculation>Now if only they go just a little bit further and add the sample extraction mechanism prototype on it and we might see a few dozen grams of lunar soil back on Earth a little bit earlier than planned.....  </speculation>

[plutogno]

an Earth return with CE-5 technology would also require a return stage waiting in lunar orbit, which should not be available

[Galactic Penguin SST]

an Earth return with CE-5 technology would also require a return stage waiting in lunar orbit, which should not be available

Well can you try a very small lunar sample (say 50g maximum) and do it like the old Soviet way (direct ascent and TEI)?

[beidou]

Though Chang'e-3 is still on its journey to the Moon, there were already some discussions on the next Chinese lunar mission - Chang'e-4. The objectives of this mission has to be defined upon the progress of Chang'e-3, but sources indicated it will also be launched on a CZ-3B rocket and has very similar payload to Chang'e-3.

Discussions can be found here:  http://bbs.9ifly.cn/forum.php?mod=redirect&goto=findpost&ptid=5819&pid=122002&fromuid=24484

[Blackstar]

I believe it was posted elsewhere that it is essentially the backup to CE-3 and therefore identical. However, that would depend somewhat upon how much actual hardware has been produced. Do we know that?

It is always difficult to make design changes late in the game, but on the other hand, you may learn something that makes you want to change either the engineering design (fix something that does not work) or the instruments.

[savuporo]

I believe it was posted elsewhere that it is essentially the backup to CE-3 and therefore identical.

Chang'e-2 was also a backup to Chang'e-1, but was _not_ identical in every detail - they did incremental additions and improvements on the base spacecraft. For example, they added X-band comms on the second.

Middle of this page there is a good side by side table of the differences:
https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-2

Presumably the same would be the case for Chang'e-4. Plus, if you plan ahead, in the first version you can leave off high risk payload components for example and add more fuel instead. On the second one, optimize your trajectories saving fuel and add more payload.

[Star One]

Is there any kind of indication at all at this stage where on the Moon this one will be targeted?

[Satori]

From Xinhua, China aims to land Chang'e-4 probe on far side of moon.

[Star One]

From Xinhua, China aims to land Chang'e-4 probe on far side of moon.

Thanks.

[D_Dom]

Must have a repeater planned to facilitate data transfer. Anybody have any details? Do the Chinese operate satellites similar to TDRSS?

[savuporo]

Must have a repeater planned to facilitate data transfer. Anybody have any details? Do the Chinese operate satellites similar to TDRSS?

They probably plan to use the orbiter part of Chang'e-4 itself as a data relay, no details

Here : http://www.unoosa.org/pdf/pres/copuos2015/copuos2015tech08E.pdf

EDIT: meh, i'm incorrect. It is a separate relay sat as Satori states below. Article describing the whole thing in a bit more detail
http://gbtimes.com/china/china-unveils-plans-far-side-moon-landing-and-hints-future-lunar-base

[Satori]

Must have a repeater planned to facilitate data transfer. Anybody have any details? Do the Chinese operate satellites similar to TDRSS?

Yes, they do. But they are planning to launch a satellite to the Earth-Moon L2 point from where it will be used to relay data and communications to Earth.

[plutogno]

don't forget that L2 maneuvers were rehearsed by the CE- test probe recently

[D_Dom]

Thanks, great detail! Looking forward to this development.

[Proponent]

According to Xinhua, Chang'e 4 will land on the lunar far side.

Chang'e 4 will be the back-up hardware for Chang'e 3 and will fly by 2020.  It's not clear to me whether a rover will be carried.

Kinda cool, I think, even if the significance is more in propaganda than science.

[plutogno]

there is already a thread on this topic
http://forum.nasaspaceflight.com/index.php?topic=33402.0

Kinda cool, I think, even if the significance is more in propaganda than science.

the Chinese have invited foreign instruments for this mission, so the stress is definitely on science.
plus, I think the last time an unmanned mission had any propaganda significance was in the early 1960s