Abstract: A series of key technical issues, such as the design of high-performance and highly reliable propulsion systems for manned lunar exploration spacecraft, lightweight high-load-bearing large-volume tanks, and throttleable engine, have been addressed. A number of concerns and systematic control measures have been proposed to solve these technical problems. The pressure and pressure difference of the storage tank are ensured by differentiating the oxygen-fuel pressure reducing valve under large system flow and by compensating for pressure drop under small flow. The thrust consistency of the four variable-thrust engines is guaranteed by balancing the upstream flow resistance of the system and the thermal calibration of individual units. The above-mentioned methods were verified through technical verification by conducting single-machine tests and system-level tests. The results show that the proposed solutions in this paper can reduce or eliminate the risks faced by various key technologies. The technical problems of pressure difference stability control of common bottom tanks under large and small flow rates and thrust consistency control of four variable-thrust engines have been solved. The pressure difference of the common bottom tank can be controlled within a small range of 0 to 0.3MPa, and the thrust deviation of the four variable-thrust engines is controlled within 100N. These researches indicate that manned lunar exploration has overcome the key technical challenges of the propulsion system, and can reliably provide power for manned lunar spacecraft, as well as offer new ideas for the design of subsequent spacecraft.

Key words: manned lunar exploration, key technologies, technical verification, pressure difference stability, thrust consistency