China's Space Program News Thread

[gelgoog]

The tendency on the rocket industry is to move towards 3d printing as much as possible.
It allows reducing the number of parts. You also waste less material.

The thing is, most launch companies don't need all that many rocket engines to be produced. The number is typically in the dozens and seldom goes to a hundred. The RL-10 engine is used in single units per rocket typically. There are exceptions like with SpaceX. But few companies build that many engines.

This means other production techniques suited for mass serial production don't make sense for rocket engines.

 

[FairAndUnbiased]

The tendency on the rocket industry is to move towards 3d printing as much as possible.
It allows reducing the number of parts. You also waste less material.

The thing is, most launch companies don't need all that many rocket engines to be produced. The number is typically in the dozens and seldom goes to a hundred. The RL-10 engine is used in single units per rocket typically. There are exceptions like with SpaceX. But few companies build that many engines.

This means other production techniques suited for mass serial production don't make sense for rocket engines.

CNC or sheet metal forming is best for mid sized production runs in the hundreds for mid sized components (~meter sized).

Materials costs for most rocket components aren't that high, it's just aluminum and stainless. Processing costs are far higher. 3D printing isn't good because of material waste for general materials, because you have to powder the material first which is even more wasteful while for CNC and sheet metal techniques you start with a block or a sheet which is how the parts come out straight from the refinery.

That's why I point out that small critical components with weird shapes or that are refractory and thus need to be powder formed anyways are the best 3D printing candidates.

 

[by78]

The No. 165 Institute of the 6th Academy of CASC has successfully completed the first test run of 18-ton Lox/Kerosene engines in parallel configuration/staging (双机并联二次启动). I believe "双机并联二次启动" means parallel staging. Please correct me if I'm wrong.

 

[taxiya]

The No. 165 Institute of the 6th Academy of CASC has successfully completed the first test run of 18-ton Lox/Kerosene engines in parallel configuration/staging (双机并联二次启动). I believe "双机并联二次启动" means parallel staging. Please correct me if I'm wrong.

It seems to be YF-115.

双机并联 is twin engine configuration, that is two engines for a stage. Most likely 2nd stage of some launcher.
二次启动 is 2nd time engine start. This confirms that the engine configuration is meant for 2nd stage which has capability for two burns.

Two burns means that the stage will burn twice separately with a engine shut off and restart and coasting period in between. It is not regarded as staging which involves separation and discarding.

The significance of this news is the twin engine configuration of YF-115. So far I am not aware of any CZ rockets having such application.

 

[Petrolicious88]

The author apparently did not read the 5 year white paper, but instead quoting from other source who did not read the white paper either. Typical "trash in trash out".

The white paper said "中国航天将深化载人登月方案论证", translated to "China will further conduct in-depth study of manned moon landing solutions" in the next 5 years.

I have been advocating in this forum that China is NOT racing with US in a childish size contest as the spacedaily article is trying to portray, this is true not only in space industry but also military and geopolitcs. It is something that China watcher must keep in mind all the time.

China needs to ignore the constant negative media coverage and just focus on its goals.

 

[taxiya]

It seems to be YF-115.

双机并联 is twin engine configuration, that is two engines for a stage. Most likely 2nd stage of some launcher.
二次启动 is 2nd time engine start. This confirms that the engine configuration is meant for 2nd stage which has capability for two burns.

Two burns means that the stage will burn twice separately with a engine shut off and restart and coasting period in between. It is not regarded as staging which involves separation and discarding.

The significance of this news is the twin engine configuration of YF-115. So far I am not aware of any CZ rockets having such application.

My gut feeling is that this may be for future CZ-6A upgrade. The thinking is in the same way as CZ-7A and its upgrade (final version). The 7A baseline has 4 YF-115 totally 72t 2nd stage, the final version has 1 YF-100M 125t 2nd stage. The aim is to increase the thrust of 2nd stage. CZ-6A's 2nd stage is 1 YF-115 same as CZ-6. It is two low.

 

[Hyper]

3D printing is just a fancy technology . They do not offer the accuracy of the level that CNC machines can offer. Wire edm alone is 100 times more accurate that 3d printing. No need to talk about diamond turning.

 

[anzha]

Don't get excited over this. it's a nonissue. The only really bad thing about this is clearly, deep space tracking isn't great still. Does any nation have a functional seismometer on the moon right now? I think that'd be China only, but IDK of any of the landers have them or not. The impact would give very (!!!) interesting data on the moon's interior.

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[taxiya]

Don't get excited over this. it's a nonissue. The only really bad thing about this is clearly, deep space tracking isn't great still. Does any nation have a functional seismometer on the moon right now? I think that'd be China only, but IDK of any of the landers have them or not. The impact would give very (!!!) interesting data on the moon's interior.

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There is no functional seismometer on the moon right now. China's landers up till now don't have it. The upcoming Chang'e-7 will have it. It will deploy a device of 22kg with explosive charge of 100 gram TNT about 500 to 1000 meters away from the lander. The lander will measure the moon-quake.

It is more accurate and reliable to do the measurement in a controlled maner than taking the opportunity of a crash.

 

[anzha]

It is more accurate and reliable to do the measurement in a controlled maner than taking the opportunity of a crash.

You are absolutely correct. OTOH, the impact will have far, far more energy than the carried explosive will. That would allow for a "deeper" probing. The controlled explosions would give an excellent calibration for the large impacts.

It's all moot though since nothing on the moon has a seismometer yet.