one thing we get is that 120t LO/LH is YF-91
China's Space Program Thread II
- Thread starter Blitzo
- Start date
That is a persistent miss-conception started by SpaceX fans from the first day when Raptor was said to use methane. I'd say it has become a cult and urban legend.
Cocking is only a thing for Kerosene if it is a fuel rich circle, not for a oxygen rich staged circle where oxygen can burn anything except the specially coated surfaces. The matter has been thoroughly studied by China before 2017, and I am sure by USSR even earlier when they developed RD-170,180 etcs.
The true advantage of a Methane engine is IF it is a fuel rich circle that avoid the harsh environment of oxygen burning the combustion chamber itself. But full flow methane engine like Raptors and the Chinese 200t are oxygen rich in their oxidizer loops, therefor facing the same problem.
The conclusion was that, there is no meaningful difference.
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This is the only design that makes sense if they want to use methane engines IMO. The earlier design of methane 1st stage + LH 2nd stage was nuts as I have said before, it creates a logistic and operational nightmare.
Of course using methane for 2nd stage degrades its performance, therefor we see the increase of total mass and thrust.
Another interesting thing is "maiden launch expected 10 years after program start". Whatever the definition of program start, 10 years is a very long time, certainly not 2030. So this design if ever materialize, is not the first CZ-9 to be flown.
Easier to store on what? Kerosene is going to be used in the first stages while on the ground. In those conditions, standard atmosphere and pressure, it is way easier to handle than liquid methane. It might be easier to store in space, but that is besides the point.
Surely you jest. You are talking about synthesizing methane out of thin air. It will never be cheap. And it makes no sense on the surface of the Earth.
You are not going to be using natural gas on it ever. Too many pollutants in natural gas including sulfur. They need to be removed before use on a liquid rocket engine.
Nope. Hydrogen is a lot better. You could make a case that nuclear thermal or electric is even better though.
Given that China has access to PBMR reactor technology, making something similar to the US Project Timberwind nuclear thermal upper stage might not be impossible.
That is another urban-legend just because SpaceX building Raptor. FFSC was firstly built as RD-270 in the 1960s by USSR, not flown because the rocket was cancelled. RD-270 used hypergolic fuel. The reason FFSC was not used in later Soviet engines because LOX/Kerosene was chosen which exclude the possibility of FFSC, not because it is difficult. The Soviets studied methane too and deemed its performance not preferable compared to Kerosene. Yes methane is worse than Kerosene in 1st stage, and worse than LH2 in 2nd stage and above.
You are apparently talking about common bulkhead tank, not storage in general. It isn't a problem for any kind of fuel. Common bulk head tank has been used by many rocket for decades including SpaceX on Falcon 9 which uses LOX/Kerosene. Space shuttle main tank use it too for LH/LOX, China's CZ-6 (LOX/Kerosene) use it as well.
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by78
General
The Hongtu-1 (宏图一号) constellation is scheduled to be launched around March of 2023. It's China's first commercial distributed interferometric X-band SAR observation constellation, with a spatial resolution of 0.5 m to 5m and capable of high-precision terrain mapping, high-resolution wide-format imaging, millimeter-level high-precision deformation monitoring, and three-dimensional imaging. Hongtu-1 constellation will be tasked to carry out topographic mapping of the world.
An update and more information on the Hongtu-1 (a.k.a. Nuwa) constellation of observation satellites. It will feature a laser inter-satellite communications network. The first phase will have 38 satellites, with the first four (X-band SAR) satellites to be launched in Q1 of 2023. The remaining 24 will be launchd in 2024 and 2025.
