China's Space Program Thread II
- Thread starter Blitzo
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The hydrogen-oxygen propulsion system for VTVL faces a density-specific impulse challenge, particularly when it comes to launching from Earth's gravitational field. The likelihood of achieving practical orbital insertion with this system is almost nonexistent, which explains why Blue Origin's New Shepard is limited to suborbital trips rather than competing with the Falcon 9 in full orbital missions. Although Blue Origin's BE-3 engine and SpaceX's Merlin-1 engine are contemporaries with comparable thrust levels (before the introduction of the Merlin 1D), and the BE-3 is technically more advanced, hydrogen-oxygen engines are unfortunately not well-suited for the initial lift-off stage. Chinese literature from around 2015/2016 specifically addressed this, emphasizing that the first stage of reusable rockets should rely on hydrocarbon-based propulsion for better performance.
LOX/Hydrogen isn't as bad as you think. The mixture ratio of a LOX/Hydrogen engine uses way more oxidizer in the mix than a LOX/Kerosene engine. And LOX has a density of roughly 1.0 kg/L i.e. it's more dense than Kerosene. The problem is you will still have more fuel tank weight and volume, the hydrogen is less dense so you will need thicker piping for the fuel, which means the trust-to-weight of the whole rocket will be worse. Finally, and this is the worst aspect, Hydrogen is liquid at 20 K, versus 90 K for Liquid Oxygen (LOX). The further you want to go into the deep cryogenic arena the more difficult it is to keep the propellant stored at the proper temperature. Propellant handling is also more difficult.
Just looking at the Delta IV Heavy rocket would make it pretty obvious to anyone that it is easily possible to make a two stage to orbit LOX/Hydrogen vehicle if you wanted to. In fact the Japanese H3-30S is basically that. A two stage to orbit LOX/Hydrogen launcher.
Just looking at the Delta IV Heavy rocket would make it pretty obvious to anyone that it is easily possible to make a two stage to orbit LOX/Hydrogen vehicle if you wanted to. In fact the Japanese H3-30S is basically that. A two stage to orbit LOX/Hydrogen launcher.
Hydrogen-oxygen propulsion for rocket booster stages faces the issue of density-specific impulse, which is a fundamental concept that space enthusiasts should be aware of. The Delta IV Heavy launch vehicle adopts a CBC configuration, and without this configuration, additional boosters are necessary. Essentially, a CBC configuration rocket is just a rocket with two additional liquid boosters. The core issue is that without the use of strap-on technology, it is challenging for hydrogen-oxygen powered rockets to serve as booster stages for escaping Earth's gravity well without the aid of boosters.
Hydrogen-oxygen propulsion is not a one-size-fits-all solution; different rocket propulsion systems are suited for specific scenarios. In 10 years, you will witness the strength of China's space program, which is built on a systematic inventory of propulsion systems of various scales and types, ready to meet the diverse needs of future space transportation. In comparison, the United States will likely be missing about 30-50% of these products. The strength of American space lies in the variety of engine types documented in the American space encyclopedia (the engine models mentioned in the question are now part of history). Today's America can no longer produce as many advanced propulsion systems for the future.
If you study how China's new energy vehicles have achieved success, you will see a similar path to victory for China's space program in the future.
Smart people do things that yield twice the result with half the effort. It's only those who are strapped for resources, lacking funding, personnel, and projects, who are forced to compromise and try to dominate with a single product. In reality, this approach often leads to spending more and gaining less, which is to say, it's a case of more effort for less reward. This is because using an unsuitable technology in an inappropriate field will ultimately lead to a greater cost and limited outcomes. Using hydrogen-oxygen propulsion for the reusable launch vehicle's booster stage engine in Earth's gravity well is a choice born of foolishness and desperation, not a choice of true strength.
by78
General
Another private space company. AZSpace, also known as Ziwei Technology (紫微科技), is based in Wuxi and develops commercial cargo spacecrafts. Its B300 commercial cargo ship is scheduled for launch in June, 2023. I'm not sure what rocket will launch it.
An update on the AZSpace/Ziwei's Dier-1 technology demonstrator cargo craft. Dier-1 has been operating smoothly since launch and has met all performance expectations. The valuable data collected from this mission will pave the way for the upcoming B300 unmanned cargo spacecraft.
AZSpace/Ziwei will launch its B300 commercial cargo ship in August, 2004. B300 comes in two versions: B300-L is non-returnable and can stay in space for one year; B300-F is designed to return to Earth intact and can operate in orbit for one month. Both versions have a cargo capacity of 300kg. In addition to transporting cargo, they are also designed to carry science experiments, which are expected to be in demand by private industry in sectors such as pharmaceuticals, material science, space biology, etc.
by78
General
According to the deputy general manager of Tianbing's production base, the Tianlong-3 launch vehicle will begin final assembly at the end of February to early March, and the final assembly and associated testing are scheduled to be completed around April or May. The rocket's maiden flight will take place in June or July.
Tianbing has confirmed the maiden launch of Tianlong-3 will be carried out at launchpad no. 2 of the Hainan Commercial Spaceport. The company's founder –– Mr. Kang Yonglai (康永来) –– said Tianlong-3 will achieve a launch cost of <20,000 yuan per kilogram.
by78
General
Some updates from ExPace, a subsidiary of CASIC. Its LOX/Methane Mingfeng-1 engine has passed all ground tests and engineering assessments, and preparations are underway for its first test flight. The Mingfeng-2 engine is also making good progress. A prototype has been assembled and will soon be ready for its first full test run.
The image below shows a Mingfeng-1 engine during a test firing.
An update on the 70-ton reusable LOX/Methane Mingfeng-2 engine being developed by ExSpace. In the past year, prototypes have undergone extensive hot test runs of various durations and scenarios, including multiple restarts and variable thrust, and performance has met all design parameters.
by78
General
LandSpace has delivered the first TQ-15A engine for the second stage of the improved Zhuque-2 rocket. TQ-15A will replace the TQ-11 and TQ-12 previously used in the second stage of Zhuque-2.
TQ-15A increases vacuum thrust by 11.8%, vacuum specific impulse by 126m/s, and has a 60%~100% thrust adjustment range, and it can be started multiple times.
TQ-15A is part of the A-family of engines that also includes TQ-12A, which improves on the TQ-12 by increasing thrust by 9% and specific impulse by 40m/s, while achieving a weight reduction of 100kg.
With the delivery of TQ-15A, the improved Zhuque-2 rocket will now enter the final assembly stage ahead of its first launch in the second half of 2024.
escobar
Brigadier
2024 G60 launch plan : 6 launches, each launch mission will carry 18 sats for a total of 108 sats.
SSST said to have the world's top two Ka-band resources, ahead of SpaceX's Starlink.
SSST said to have the world's top two Ka-band resources, ahead of SpaceX's Starlink.
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