China's Space Program Thread II

[AndrewJ]

Everyone in this thread should read some posts to know more about LM-10 design.

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"The Long March 10 uses a lot of mature technologies from the Long March 5, such as the YF100 series liquid oxygen-kerosene engines widely used in the new generation of Long March rockets. Compared with the Long March 5 and other models, not only has the thrust of a single engine increased from 120 tons to 130 tons, but more importantly, the pump has been changed from front to rear, and the space occupied by each engine has been greatly reduced. Seven engines can be installed in a 5-meter diameter rocket body, while the original YF100 engines can only be installed in the 3.35-meter diameter booster of the Long March 5." Yang Yuguang introduced that this makes it possible to connect 21 engines in parallel.
The Long March 10 uses a parallel solution of 7 YF-100 engines in each module and 21 YF-100 engines in three modules. Since the YF-100 series has been installed on new rockets such as the Long March 5, Long March 6, Long March 7, and Long March 8 since 2016, it has experienced many launches and can be said to be "time-tested" and very mature. Compared with the 33 new liquid oxygen-methane engines in parallel on the "Starship", the power system of the Long March 10 is much more mature and the technical difficulty is much lower. It is a very safe choice for manned lunar landing.

The core stage and booster diameters of the Long March 10 are both 5 meters, the same as the core stage of the Long March 5. Why choose the Long March 10 with a longer body of the Long March 5 to launch two rockets for a lunar landing instead of a giant rocket like the Saturn V with a diameter of 9-10 meters to achieve a manned lunar landing with one rocket?
Yang Yuguang stressed that the diameter of a rocket is a very important indicator. "During the production process of a rocket, the rocket body can be flexibly spliced, so the length is not a big problem. However, the diameter of the rocket body determines the specifications of many infrastructures, so the diameter of the rocket cannot be easily changed." Yang Yuguang said that if the Long March 10 uses the mature five-meter diameter rocket body of the Long March 5, it means that many production facilities and equipment including processes and tooling can be directly used, which saves a lot of money and time costs.

In short, LM-10's all first stage engines YF-100K are upgrade version of LM-5's booster engine YF-100. And also the core stage/boosters' diameter remain the same as LM-5's core stage. Which significantly reduce LM-10's research & develop time.

According to CCTV News, the Long March 10 is a three-and-a-half-stage rocket developed for the manned lunar exploration project to launch a new generation of manned spacecraft and lunar landers. The rocket is 92.5 meters long, has a takeoff weight of approximately 2,189 tons, and a takeoff thrust of approximately 2,678 tons. Its Earth-Moon transfer orbit carrying capacity is no less than 27 tons, which is more than three times that of the Long March 5 rocket. Its low-Earth orbit carrying capacity is approximately 70 tons, which is also about three times that of the Long March 5.
The non-boosted rocket derived from this type of rocket can carry out space station astronaut and cargo transportation tasks, and the first stage has a reusable function. It is about 67 meters long, has a takeoff weight of about 740 tons, a takeoff thrust of about 892 tons, and a low-Earth orbit carrying capacity of no less than 14 tons.
What is exciting is that in the future, the Long March 10 is expected to achieve the recovery and reuse of the first stage. According to Xu Hongping, an expert from the China Academy of Launch Vehicle Technology, the reusable design of the Long March 11 stage has been verified by scale-down.

Seems LM-10A reusable version is never prepared for the lunar mission? And LM-10 always functions as a whole, only for non-reusable missions? Which means boosters are always not reusable?

 

[vincent]

And what of the CZ-10A, which I stated from my very first post that China should try to land first? Also, we have no idea of the launch schedule of the CZ-10. Are they gonna launch the Mengzhou on a lunar transfer orbit on it's very first flight? That's a very expensive payload to be risking for the maiden flight of a rocket, when maiden flights of most rockets don't have a good track record. Maybe they will, but it's not a sure thing. And again, the Mengzhou without crew and a week's worth of supplies on board will be a lot lighter, maybe enough for a landing, even with a lunar orbit. Yes, there will be missions that will not allow for reuse, but that doesn't mean that you can't try on missions that do allow it.

The gap between the LM-5 and CZ-10 is huge. There's not much overlap between them. There will be missions that's only possible with the LM-10 that still allow for reuse, even if not landing all 3 core stages at once.

Oh yes, the expendable medium lift rocket that has launched once. Totally comparable to the super heavy lift triple core reusable design of the LM-10. What's next? A modern ferrari is the same as a 1978 toyota cressida just because they use the same tyres and windshield wipers?

Tacoburger, stop derailing the thread, again!

 

[Xiongmao]

I know nothing about rocket science, but if I was going to put humans into a rocket to somewhere like the moon, I would want to make sure that every part of that machine is brand spanking new straight out of a factory and never been stressed in use before. So testing reusability in manned lunar missions would be a waste of time and other resources.

 

[Hitomi]

The pursuit of reusability should not interfere with the manned lunar mission or any future manned mission. National prestige is at stake. Let the Americans cope with their reusability a few more years if need be.

 

[gpt]

The pursuit of reusability should not interfere with the manned lunar mission or any future manned mission. National prestige is at stake. Let the Americans cope with their reusability a few more years if need be.

He is right in that they need reusable rockets asap for economic and military considerations, since the market has largely shifted towards LEO. Not really a concern for CMSA and CLEP because lifting heavy payloads to TLI is almost certainly a 100% expendable job.

 

[Asug]

I know nothing about rocket science, but if I was going to put humans into a rocket to somewhere like the moon, I would want to make sure that every part of that machine is brand spanking new straight out of a factory and never been stressed in use before. So testing reusability in manned lunar missions would be a waste of time and other resources.

This is an eternal dispute that has no solution) Which plane would you prefer to fly on: one that has just left the factory floor, or one that has already flown several times?

 

[tphuang]

As antwerpy continue to be disruptive, he is banned from this thread.

 

[Xiongmao]

This is an eternal dispute that has no solution) Which plane would you prefer to fly on: one that has just left the factory floor, or one that has already flown several times?

I don't see any dispute here. Rockets go through much greater mechanical and heat stresses during operation than a plane. Most rockets are also designed on the drawing board to work first time and only time. Planes are designed for multiple uses from the start. This is like chalk and bananas.

 

[taxiya]

I don't see any dispute here. Rockets go through much greater mechanical and heat stresses during operation than a plane. Most rockets are also designed on the drawing board to work first time and only time. Planes are designed for multiple uses from the start. This is like chalk and bananas.

That is very wrong assumption. Rocket is designed to run once only, but most of its engines are test fired on ground before installation, they are far from "brand new". Not burning them first put risk of them failing in flight. This kind of test fire is regular routine and has been reported by CCTV.

 

[taxiya]

He is right in that they need reusable rockets asap for economic and military considerations, since the market has largely shifted towards LEO. Not really a concern for CMSA and CLEP because lifting heavy payloads to TLI is almost certainly a 100% expendable job.

But that was never the subject of the discussion (manned moon landing mission). And more importantly we don't need him to tell what we all know.