China's Space Program Thread II

[by78]

A lunar landing mechanism inspired by cats. The full original paper in Chinese can be

Please, Log in or Register to view URLs content!

. I have also attached a translated PDF to this post.

Abstract: Aiming at the problem that the buffering force of the existing passive aluminum honeycomb lunar lander fluctuated greatly and could not be reused, the cat inspired lunar landing mechanism based on magnetorheological damper is proposed. Firstly, the jumping and landing experiments of house cats from different height platforms are carried out, and the attitude and the impulse of their front/rear legs touching the ground are analyzed to explore the buffering and absorption mechanism of house cats. The results show that rear legs absorb more than front legs. Secondly, based on the cat jumping experiments and the parameters of China’s Chang’e series lunar landers, a novel cat inspired landing buffering mechanism is designed, simulated and compared. The results show that the maximum acceleration of the proposed cat inspired lander is reduced by 18.3% and has better landing performance. The shock absorption contribution of the front legs is about 40%, and that of the rear legs is about 60%, which is basically consistent with experiments of house cats. The rationality of the proposed lunar landing buffering mechanism design is verified.

 

[taxiya]

A lunar landing mechanism inspired by cats. The full original paper in Chinese can be

Please, Log in or Register to view URLs content!

. I have also attached a translated PDF to this post.

Abstract: Aiming at the problem that the buffering force of the existing passive aluminum honeycomb lunar lander fluctuated greatly and could not be reused, the cat inspired lunar landing mechanism based on magnetorheological damper is proposed. Firstly, the jumping and landing experiments of house cats from different height platforms are carried out, and the attitude and the impulse of their front/rear legs touching the ground are analyzed to explore the buffering and absorption mechanism of house cats. The results show that rear legs absorb more than front legs. Secondly, based on the cat jumping experiments and the parameters of China’s Chang’e series lunar landers, a novel cat inspired landing buffering mechanism is designed, simulated and compared. The results show that the maximum acceleration of the proposed cat inspired lander is reduced by 18.3% and has better landing performance. The shock absorption contribution of the front legs is about 40%, and that of the rear legs is about 60%, which is basically consistent with experiments of house cats. The rationality of the proposed lunar landing buffering mechanism design is verified.

Things that I can summarize from this paper.

1. Using magnetorheological damper instead of one time honeycomb aluminium that leads to
2. Reusable for multiple jumps.
3. Much better abortion catachrestic due to active controllable damper.
4. Cat inspired control algorithm for landing on uneven and/or slopped surface.

 

[taxiya]

So here are the known YF-100 variants:
YF-100K: nozzle swivels on 2 axis after turbine-pump. 125t thrust
YF-100L: fixed nozzle? 125t thrust
YF-100M: vacuum variant, 146t
YF-100N: designed for reusable rocket (2 stage CZ-5DY). 130t thrust

other figures except YF-100N are from "Overall Scheme and Key Technologies of New Generation Lunar Manned Launch Vehicle" published in August 2022.

 

[by78]

On November 27th, China successfully launched the Yaogan-36 satellite into space using a Long March 2D rocket. The rocket also carried a de-orbiting sail. This was the 451st launch of the Long March series of rocket and the 70th launch of the Long March 2D rocket, which has not experienced a single failure thus far.

 

[taxiya]

An academic paper on vertical landing recovery using cables. Click here to

Please, Log in or Register to view URLs content!

. A machine-translated version is attached to this post.

Finally I finished reading the paper. It is a vertically mounted EM arresting gear. Deceleration is done by magnetorheological fluid damper whose force is controlled electronically.

I love the idea better than landing legs, not only it removes lot of deadweight from the rocket (more useful payload) but also guarantees that the rocket won't fall on the side once captured.

The solution gives me the same feeling of seeing J-20's solution of side weapon bay compared to F-22. Simpler and more reliable.

 

[BoraTas]

China should develop this kind of weapons, I am sure USA is working on it , they have huge number of satellite & advantage in reusable rockets

Rods from the god is s stupid concept. A nuke fitted on an ICBM is much more flexible, a lot less vulnerable, more destructive by thousands of times and a thousand times cheaper. Rods from the god is worse than the Schwerer Gustav as a concept. Destructiveness alone doesn't make a good weapon.

 

[taxiya]

China should develop this kind of weapons, I am sure USA is working on it , they have huge number of satellite & advantage in reusable rockets

I sincerely wish whichever country you are from goes full in this solution. I wish your country is convinced of its invincibility to dump all your ICBM and SSBN in exchange for this mighty weapon.

 

[gelgoog]

You need massive acceleration for those rods to come down. Once something is orbiting the earth at orbital velocity it is not that trivial to send it back down. Let us say you use a mass driver like a coilgun to shoot the rods down. Then you have to handle "recoil" and things like that. When you push a mass out in a certain direction, you get an opposing force sending the satellite in the opposite direction.

The actual effective solution to orbital defense platforms is not Rods from God but a proposal a US general made called Smart Rocks, and which Teller and co. appropriated by calling it Brilliant Pebbles. i.e. satellite based strategic missile defense using missiles stationed in space. Launching missiles, which have their own propulsion, from a satellite has none of the issues of something like Rods from God.

It is precisely to preempt US moves like this that Russia is working on multiple systems including air breathing nuclear cruise missiles and the intercontinental submarine torpedos. Something like Smart Rocks will be ineffective against either weapon.

 

[Blitzo]

https://twitter.com/i/web/status/1595198196770226176

Long March9 first launch in 8 to 10 years and prototype has already been built.

Short-duration hot fire tests of all 3-stage engines have been conducted

If hot fire tests of all 3 stages have been done, in terms of the first stage, wouldn't that mean that it has to refer to the YF-130 (assuming he views a single chamber variant as related to it) as no other first stage engine that would qualify for CZ-9 would fit the bill?

Assuming he is still talking about the reusable single stick CZ-9 variant, then it seems to me like there may be two CZ-9 variants in active development both using similar physical architecture but with different engines.
For 2030, CZ-9 with a single chamber YF-130.
For 2035, CZ-9 with new metholox engine.

 

[ZeEa5KPul]

If hot fire tests of all 3 stages have been done, in terms of the first stage, wouldn't that mean that it has to refer to the YF-130 (assuming he views a single chamber variant as related to it) as no other first stage engine that would qualify for CZ-9 would fit the bill?

Assuming he is still talking about the reusable single stick CZ-9 variant, then it seems to me like there may be two CZ-9 variants in active development both using similar physical architecture but with different engines.
For 2030, CZ-9 with a single chamber YF-130.
For 2035, CZ-9 with new metholox engine.

Where does the YF-135 fit into this picture?