Disclosed are a method of flying on the moon and a device for flying using the method. A medium on a surface of a moon and a medium accelerating module are used in the flying method. The medium is transferred into the medium accelerating module, accelerated by the medium accelerating module, and ejected out of the medium accelerating module by using a power supply. A counterforce is generated in accordance with the momentum conservation, and the counterforce overcomes the lunar gravity and drives a load to take off. The method is suitable for the environment of the moon where flight by means of atmospheric buoyancy is impossible due to the shortage of atmosphere.

A method includes controlling a bearing fluid supply system to provide the bearing fluid to a hydrostatic bearing of the turbopump assembly. The bearing fluid includes a supercritical working fluid. The method also includes receiving data corresponding to a pressure of the bearing fluid measured at or near a bearing fluid drain fluidly coupled to the hydrostatic bearing, determining a thermodynamic state of the bearing fluid at or near the bearing fluid drain based at least in part on the received data, and controlling a backpressure regulation valve to throttle the backpressure regulation valve between an opened position and a closed position to regulate a backpressure in a bearing fluid discharge line to maintain the bearing fluid in a supercritical state in the hydrostatic bearing and/or at or near the bearing fluid drain.

A gas turbine engine includes a shaft having a first air compressor coupled thereto, a combustor positioned to receive compressed air from the first compressor, and a power source coupled to the shaft, the power source powered by a working fluid other than the compressed air.

A method includes controlling a bearing fluid supply system to provide the bearing fluid to a hydrostatic bearing of the turbopump assembly. The bearing fluid includes a supercritical working fluid. The method also includes receiving data corresponding to a pressure of the bearing fluid measured at or near a bearing fluid drain fluidly coupled to the hydrostatic bearing, determining a thermodynamic state of the bearing fluid at or near the bearing fluid drain based at least in part on the received data, and controlling a backpressure regulation valve to throttle the backpressure regulation valve between an opened position and a closed position to regulate a backpressure in a bearing fluid discharge line to maintain the bearing fluid in a supercritical state in the hydrostatic bearing and/or at or near the bearing fluid drain.

A gas turbine engine includes a shaft comprising a first compressor, a fan assembly, and a power circuit that provides power to the shaft in a closed-loop system. An inner housing houses at least a portion of the shaft, the first compressor for compressing a core stream of air, and a combustor. A baffle encloses a portion of the inner housing and forms a first air passageway therebetween. A nacelle encloses a portion of the baffle and forms a second air passageway therebetween. A heat exchanger is positioned in the second air passageway that rejects heat from the power circuit into a heat rejection stream of air passing through the second air passageway. Air is accelerated as streams in parallel and via the fan assembly as the core stream into the inner housing, as a bypass flow stream of air through the first volume, and as the heat rejection stream.