The general integral equations are derived for liquid and gas components of space propulsion systems with liquid propellant rocket engine.

针对采用液体推进剂火箭发动机的空间推进系统，推导了系统液路和气路的通用积分形式方程。

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Export controls also prompted the European Space Agency to pay to develop a European supplier of solenoid valves, so that European space-propulsion systems do not depend on this American part.

ECONOMIST: Space technology

What are the main propulsion systems for spacecraft in space?

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