Author Topic: Speculation: How could China technically land people on the Moon  (Read 13114 times)

Offline Blackstar

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Again, since I don't read Chinese, I'm limited in what I can actually understand or comment on with this paper. They are discussing a theoretical new Chinese human spacecraft. But that presupposes that one is actually needed for future missions. For instance, they note that one criteria is lower cost. But if Shenzhou does not cost all that much today, then that may not be a problem. Similarly, how much flexibility does Shenzhou have to perform other missions. For example, can it handle lunar reentry speeds? Can it be easily adapted to handle lunar reentry speeds?

It's an interesting thought experiment and may be worthwhile. Suppose that China's plans for human spaceflight for the next 15 years are simply to build their LEO space station and keep flying to it throughout the 2020s. Will they need a bigger and more capable spacecraft for the 2030s to do things like lunar missions? They might. And there are reasons to not want to be flying the same spacecraft that was designed in the 1990s thirty years later.


Online Steven Pietrobon

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The current version of Shenzhou probably can't handle Lunar re-entry speeds, but with a thicker heat shield, I'm sure it could. The Lunar Soyuz could do this, and the Chinese have already tested the basic capsule shape with Chang'e 5-T1.

I agree that a bigger spacecraft is required for Lunar missions, that but does not mean a bigger capsule. ShenZhou only needs a thicker heat shield, large antenna for communications, a bigger service module and probably additional radiation shielding in the orbital module. Going to a large Orion like design is very inefficient for Lunar missions. The radiation shielding has to be in the capsule, which means a heavier heat shield, along with everything else that could be carried in the orbital module. I believe that is one reason why the Orion capsule is so heavy at 9 to 10 t, which means a corresponding heavy service module. In my opinion the Soyuz configuration is optimal for Lunar missions. It keeps the capsule as small as possible to minimise overall mass, while having a large internal volume with the orbital module. The Shenzhou capsule and orbital module is only 4.75 t. Radiation shielding and a thicker heatshield will increase that. I'm not sure by how much, but it should still be a lot less than an Orion type design.

If going to LEO only, a large capsule makes more sense, as you can carry a lot of people for the short time required to go to a Space Station, where an orbital module is not really required.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline luhai167

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Steven, I am not doubting that they are from Chinese sources.   

Dwayne Day had a Space Report article years ago with the multiple CZ-5 profile which was speculation from a western writer: then the Chinese media picked up on the concept and I have seen it repeated in Chinese literature.

They are from Chinese sources, there is a sizable portion in the Chinese space community is advocating for a moon program, and a bunch of papers would come out every couple of years. (Which is also a good indication that such program is not officially in plans. ) The one Beidou posted is just the latest in a series of paper, I also attached one from 2010. They essentially argue the following:
1. The technology to go to the moon is well with in reach of China's technological level
2. Going to the moon today will be less costly (proportional to the economy) to do compare to the Apollo program.
3. Technology developed for the moon program will be used for future and further space explorations. China will should not go to the moon, then stop.
4. Other nations has plans as well, and developing towards that direction. If China doesn't follow suit, it will be left far behind.

Offline TrevorMonty

If they are going to stay or visit frequently then a cislunar gateway and reusable lander is way to go. This approx does need a LV that can deliver around 15t to gateway but not necessarily a SLS class vehicle.

Offline Blackstar

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needs a thicker heat shield, large antenna for communications, a bigger service module and probably additional radiation shielding in the orbital module.

Why would additional radiation shielding be required? Unless they wanted really long duration missions, most lunar missions would be on the order of a week or two, which is perfectly fine. I also don't think that the radiation load at the Moon is all that much greater than in Earth orbit. You're still going to get some reduction from the Moon covering part of the sky (thus blocking some of the galactic cosmic radiation).

Now a lunar-Shenzhou would require some additional systems like a heavier heat shield. But they would also probably want to get some weight reduction too, because the rocket equation works badly when you have to carry all that mass to the Moon and back (so at the very least it would be nice to discard some things at the Moon so that you don't have to bring them back). But I don't see why an all-new vehicle would be necessary as opposed to some significant upgrades.
« Last Edit: 04/03/2015 05:30 PM by Blackstar »

Online Steven Pietrobon

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Why would additional radiation shielding be required?

My understanding is that additional radiation shielding is required in case there is a solar storm. According to

http://www.marssociety.org/home/about/faq#TOC-Q:-What-are-the-dangers-from-radiation-in-transit-and-on-the-surface-of-Mars-

a solar storm can give a 38 rem dose inside a spacecraft, which is below the 75 rem dose from an atomic bomb or a nuclear plant meltdown. Mars Direct claims that has little effect, but some might disagree with that. With additional protection, the dose can be reduced to 8 rem. I think the latter would be preferable, but it may be difficult without substantially increasing the mass.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline Blackstar

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Why would additional radiation shielding be required?

My understanding is that additional radiation shielding is required in case there is a solar storm. According to

http://www.marssociety.org/home/about/faq#TOC-Q:-What-are-the-dangers-from-radiation-in-transit-and-on-the-surface-of-Mars-

a solar storm can give a 38 rem dose inside a spacecraft, which is below the 75 rem dose from an atomic bomb or a nuclear plant meltdown. Mars Direct claims that has little effect, but some might disagree with that. With additional protection, the dose can be reduced to 8 rem. I think the latter would be preferable, but it may be difficult without substantially increasing the mass.

For Mars, not the Moon. The best way to protect against a solar storm is mission duration: the shorter the mission, the less likely is a solar storm. That's not an option for Mars where the spacecraft is going to spend at least 6+ months going to and 6+ months returning from Mars. If China wants to send humans to the Moon, a 2-week duration mission should be fine.

Offline baldusi

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Apollo's contingency plan was simply to point the SM towards the Sun. I would guess that they could do exactly the same.

Online Steven Pietrobon

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Some possibly new information on the CZ-9. We've seen this ring before in November 2014, but this appears to be a new image. The image of the CZ-9 may possibly be fan art.

http://www.chinadaily.com.cn/china/2016-01/11/content_23017692.htm

Lunar mission moves a step closer

China has developed the manufacturing techniques for a key part to be used on its super-heavy rocket that will fulfill the nation's manned missions to the moon.

The China Academy of Launch Vehicle Technology, working with other Chinese institutes, has developed a super-large interstage ring to be used to connect stages of the rocket, tentatively called the Long March 9.

The development was announced in a news release by China Aerospace Science and Technology Corp, the country's major space contractor.

The release said an interstage ring is a key component in a multistage rocket, and that those used on China's current rockets were made in sections before being assembled.

In contrast, the ring on the Long March 9 will be made through a casting method that produces it in one piece.

The China Academy of Launch Vehicle Technology has begun preliminary research on the Long March 9. The work has been approved by the State Administration of Science, Technology and Industry for National Defense, which is in charge of the nation's space programs.

According to sources at the academy, it plans to take up to five years to design and develop a liquid oxygen/kerosene engine with 460 metric tons of thrust and a oxygen/liquid hydrogen engine with 220 tons of thrust.

The rocket will have a launch weight of 3,000 tons and is scheduled to make its maiden flight around 2030, the sources said, adding that it will play a key role in helping to land astronauts on the moon.

The Long March 9's technical specifications have still to be disclosed.

But Li Tongyu, head of aerospace products at the academy, said its diameter and height will be much greater than those of the Long March 5, which is undergoing final tests and will make its first flight soon. The Long March 9's thrust will also be much stronger, Li said.

"Our current launch vehicles, including the Long March 5, will be able to undertake the country's space activities planned for the next 10 years, but they will not have the capacity to carry out the nation's long-term space programs," according to Li.

Li Jinghong, deputy chief designer of the Long March 3A at the academy, cited technical estimates stating that the Long March 5 will require four launches before fulfilling a manned mission to the moon, while the Long March 9 will need only one.

The senior engineer also said that the Long March 9 will not be used solely for lunar missions, hinting that it will be required for other deep-space exploration projects.

Tian Yulong, secretary-general of the China National Space Administration, said it has started preliminary research on a Mars exploration program.
« Last Edit: 01/17/2016 06:47 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

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