Long March (space rockets)

2022: Announcement

In early September 2022, the Beijing Space Research Institute tested a new rocket engine that is twice as powerful as its American rival in the race to land the next astronaut on the moon.

Ground tests were carried out on September 5, 2022 with complete success, the China Aerospace Science and Technology Corporation (CASC) said. The engine will be used to launch Chinese Long March 9 rockets, which are still under development, and to deliver astronauts in future missions to the moon, CASC said.

China has created the world's most powerful closed-circuit liquid-propellant rocket engine

The booster rocket engine can generate a force of 25 tons, more than twice the thrust generated by RL10, an American-made engine expected to take American astronauts back to the moon. Upper stage rocket engines are used at high altitudes to generate additional thrust to get the spacecraft to its destination.

CASC said it was the world's largest closed expansion cycle engine test launch for September 2022, marking a breakthrough in the development of key technology for super-powered launch vehicles. Closed expander cycle rocket engines are the most efficient source of energy for human spaceflight. Engines can convert a small amount of liquid hydrogen fuel into high-pressure gas using waste heat.

The gas drives the turbines to increase the pressure of hydrogen and oxygen in the fuel pumps. The gas then enters the top of the combustion chamber for use as fuel. This cycle, known as closed expansion, is more efficient than the combustion process in conventional rocket engines because it does not require the rocket to carry additional gas to power the pumps.

However, according to Chu Baoxin's lead engine project scientist at the Beijing Aerospace Institute, increasing engine thrust with a closed expansion cycle is quite difficult. A complex mission, such as a moon landing, requires the engines to turn on and off many times. Each time, the engine should generate enough excess heat, transfer it to liquid hydrogen, turn it into gas and bring the fuel pump to a normal operating speed as quickly as possible, according to Chu's team. When the engine is at full power, the vaporized hydrogen pressure can become extremely high and difficult to realize. The larger the engine, the more serious these problems become.

Chinese rocketeers said they had found a way to increase thrust. They invented a new heat exchanger consisting of a variety of ribbed components that can absorb heat from the surface of the combustion chamber and transfer it to liquid hydrogen with unprecedented efficiency, the team said in a recent paper in the peer-reviewed journal Journal of Rocket Propulsion. The components were manufactured using the latest 3D printing technology to produce an extremely smooth surface that can accelerate heat transfer much faster than traditional components.

The researchers also used new titanium alloys to make gas-fired fuel pumps, which can maintain high efficiency when operating in extreme conditions, the paper says. It would take four new engines working together to get Chinese astronauts to the moon, Chu said^[1]

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