Chang'e 5 thermal vacuum test complete!

[xenomorph555]

The Chinese have successfully completed a thermal vacuum test of the Chang'e 5 return capsule, this is an important test for any spacecraft and proves it is ready to survive in space. They are also done months prior to the mission.

This with the re-entry test done last December and a propulsion system rocket sled test in 2012 leads me to believe they are nearly ready.

They have stated the flight will happen later this year, probably November or December.

So we have a new moon mission to look forward to

However it is important to note this mission is a test of the re-entry spacecraft (capsule and propulsion) to the moon but not the actual sample return mission.

[K^2]

So it's supposed to be a fly-by and return? Something similar to Apollo 8?

[Streetwind]

Shouldn't Chang'e 4 happen before that, though?

[Kryten]

Shouldn't Chang'e 4 happen before that, though?

This is the Chang'e 5 precursor mission; the actual Chang'e 5 mission isn't scheduled until 2017. This is just a systems test of the return capsule and orbiter bus using a lunar fly-by.

So it's supposed to be a fly-by and return? Something similar to Apollo 8?

It's a free-return trajectory, so more like the soviet Zond missions. It even has the same capsule shape, if scaled down;

Edited June 20, 2014 by Kryten

[Nibb31]

That's actually much bigger than I thought it would need to be for a simple sample return capsule. The plans is to return 2Kg of lunar material, but you could nearly fit a person inside that capsule!

It's also a whole lot of mass to land on the moon and return... Their plan is to do a LOR so I assume that the mission profile is something like this:

- Launch sample capsule (SC), ascent module (AM), descent module with robotic arm (DM), and return module (RM) into lunar orbit.

- Detach RM

- Land SC+AM+DM.

- Pick up samples with DM's arm and load them into SC.

- Launch SC+AM

- Rendez-vous and dock SC+AM with RM.

- Jettison AM and return to Earth

At least that's how I'd do it.

Edited June 20, 2014 by Nibb31

[theend3r]

Let's hope it'll end better than their Yutu rover.

[Kryten]

It's also a whole lot of mass to land on the moon and return... Their plan is to do a LOR so I assume that the mission profile is something like this:

- Launch sample capsule (SC), ascent module (AM), descent module with robotic arm (DM), and return module (RM) into lunar orbit.

- Detach RM

- Land SC+AM+DM.

- Pick up samples with DM's arm and load them into SC.

- Launch SC+AM

- Rendez-vous and dock SC+AM with RM.

- Jettison AM and return to Earth

Correct. Here's the full spacecraft configuration;

note docking ring on top of the return capsule.

[Streetwind]

This is the Chang'e 5 precursor mission; the actual Chang'e 5 mission isn't scheduled until 2017. This is just a systems test of the return capsule and orbiter bus using a lunar fly-by.

Aaah, I see. I mistakenly assumed they'd be numbering each flight straight through, something like Apollo. But it seems like this is more a case of "Chang'e 5" being the program name, with multiple individual flights in itself.

[Nibb31]

Correct. Here's the full spacecraft configuration;

If that picture is right, then I was wrong. It means that the capsule does not go down to the ground, but that the sample is robotically transferred over in lunar orbit, which adds a lot more complexity and risk of losing stuff.

The capsule still looks wildly oversized for a 2kg sample. It's bigger than the entire descent module. I assumed it would be sized more like the Stardust capsule:

Or like this early Chang'e 5 concept that used a smaller capsule and direct ascent.

This capsule seems awfully wasteful to me, unless the design is to be used for something else... Maybe as a scale model of Shenzhou for validating the heatshield and reentry parameters for a manned lunar mission.

Edited June 20, 2014 by Nibb31

[Kryten]

Where do you get the 2kg figure? I can't find a source right now, but I think it's closer to 20.

[xenomorph555]

Apparently biological experiments will be flying onboard, like zond 7.

Personally I believe it's secretly testing a lunar shenzhou concept....

[Nibb31]

Where do you get the 2kg figure? I can't find a source right now, but I think it's closer to 20.

The original plans called for 2kg. That's what you find on Wikipedia and various blogs when you Google "Chang'e 5 sample".

Maybe you have better info, but there isn't much to gain in gathering 20 kg rather than 2 kg from such a small area. Science is better served by variety than by quantity, and variety of the samples is limited by the reach radius of the arm. I would guess that 2 kg is more than adequate.