China's Space Program Thread II

[iantsai]

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我国载人登月火箭长征十号的主发动机昨天又完成了一次点火试车，验证了火箭飞行任务对发动机的要求，为发动机技术状态固化、产品技术基线确立、可靠性提升提供了有力支撑。

The main engine of China's crewed moon landing rocket CZ-10 completed another ignition test run yesterday(July 22, 2023), verifying the requirements of the launch mission for the engine and providing strong support for the solidification of the engine's technical status, establishment of the product's technical baseline and reliability enhancement.

This derived YF-100 engine can provide more than 130 t thrust at sea level and would be installed for the Core Section and boosters of the CZ-10 rocket.

 

[taxiya]

Why do they write about the grid fins on the 1st stage? Where is the stage separation line of the CZ-2D?View attachment 116224View attachment 116225

Read the second sentence of the post

 

[by78]

High-resolution images of the latest test of YF-100K, which is destined for the first stage of Long March 10. Some Chinese sources say the test run reached a thrust of 13 tons. I assume the figure is for sea level, which is a bit of surprise to me. I thought the max thrust level was 12 tons at sea level and 13 tons for vacuum, or am I out of date on the latest developments?

 

[by78]

High-resolution images of the latest Long March 2D launch that put four satellites into orbit. This launch is also the first time a Long March 2D has used the newly developed 4-meter-diameter fairing (last image).

 

[by78]

(Continued from above...)

The Chinese prime minister recently toured Beijing GalaxySpace (a.k.a. Galaxy Aerospace), a private company that develops LEO broadband communications satellites.

Of interest is a presentation slide that shows the company's

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5G broadband satellites (top left), which will be stackable (similar to Starlink). It looks like prototype(s) already exist.

The next generation 5G broadband satellites from GalaxySpace have left the factory and will be launched on July 23rd from Taiyuan launch center. The satellites are stackable and features flexible solar panels.

Orbit: 508km sun-synchronous, near-circular
Design life: 5 years
Take-off mass: ≤330kg
Power consumption: 4500W
Measurement and control frequency band: X-band/V-band
Dimensions: 2.1m × 3.35m × 0.6m

The Lingxi-03 (灵犀03) 5G broadband satellite launched today was developed by GalaxySpace (银河航天). It will be used to verify the company's next generation broadband internet technology. The satellite also features flexible solar panels, which is a first for a Chinese satellite. The panels are only 1mm thick and only 5mm thick when folded.

 

[taxiya]

High-resolution images of the latest test of YF-100K, which is destined for the first stage of Long March 10. Some Chinese sources say the test run reached a thrust of 13 tons. I assume the figure is for sea level, which is a bit of surprise to me.

I thought the max thrust level was 12 tons at sea level and 13 tons for vacuum, or am I out of date on the latest developments?

That is the old YF-100 on CZ-5,6,7,8.

The new YF-100 for CZ-10 are YF-100K/L/N, they are 130t class according to this paper 130吨级泵后摆高压补燃液氧煤油发动机关键技术研究. It can be found here

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and

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[by78]

That is the old YF-100 on CZ-5,6,7,8.

The new YF-100 for CZ-10 are YF-100K/L/N, they are 130t class according to this paper 130吨级泵后摆高压补燃液氧煤油发动机关键技术研究. It can be found here

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and

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View attachment 116254
View attachment 116255

Thank you.

 

[taxiya]

In a hindsight, I think we should not take reliable sources or rumors for granted.

Do we remember how we got the 100t thrust? From any official paper? I don't remember seeing it. Didn't people assume the 100 in YF-100 means engine thrust level, therefor named the 480t engine YF-480 instead. How did that assumption come? No Chinese rocket engine were named after their thrust level, not before YF-100, nor after.

I think this is what happened. Somebody with access to early development process saw 100t thrust in one of many tests, combined with the YF-100 designation made that assuption, then 100t got stuck among people.

So I think that the reliable sources or even insiders may got a "right" figure but without knowing the context and make wrong conclusions without knowing it. That is why I always want to see the raw data, not necessarily classified information, but the information with context without being filtered by the source. In a way, I don't necessarily trust the logical and analitical competence of any source.

 

[iantsai]

In a hindsight, I think we should not take reliable sources or rumors for granted.

Do we remember how we got the 100t thrust? From any official paper? I don't remember seeing it. Didn't people assume the 100 in YF-100 means engine thrust level, therefor named the 480t engine YF-480 instead. How did that assumption come? No Chinese rocket engine were named after their thrust level, not before YF-100, nor after.

I think this is what happened. Somebody with access to early development process saw 100t thrust in one of many tests, combined with the YF-100 designation made that assuption, then 100t got stuck among people.

So I think that the reliable sources or even insiders may got a "right" figure but without knowing the context and make wrong conclusions without knowing it. That is why I always want to see the raw data, not necessarily classified information, but the information with context without being filtered by the source. In a way, I don't necessarily trust the logical and analitical competence of any source.

The number after "YF" is always a type code and never indicating the thrust of the engine. There are plenty of rocket engines which the type number don't match the thrust specification.

First, the engine could be optimized or upgraded continuously and thus the thrust vary a lot. Secondly the engine could also be enhanced in thrust/weight ratio and/or decreased in fuel comsumption rate and/or total weight without obvious thrust change. Also, there could be different engines with a same thrust.

So if the type codes were thrust related, it would be absolutely confusing.

 

[tacoburger]

I wonder why chinese rocket engines seem to be so static. Spacex constantly squeezes more and more performance out of the Faclon 9 and the Merlin engine, you would think that some of the workhorse rockets of the long march series would have undergone the same treatment, even before Spacex revolutionized the industry considering their sheer age. I do hope that the newer rocket variants like the long march 8, 6 or the ones still in development like the LM10 continue to get engine upgrades throughout their service life.