A space electric propulsion system and a xenon filling method therefor are provided, suitable for a filling process of an electric propulsion system using high-purity xenon as a working medium. By reasonably designing a filling process, the precision of a xenon filling amount is ensured, and xenon filling can be performed without weighing the whole spacecraft. This method features a simple and efficient filling device, short preparation time, precise and controllable filling process, as well as safety and convenience, which can effectively meet the requirements for a high-purity xenon rapid filling task of a satellite.

A fill control system and method are provided. The system may include valves connecting a cryogen vessel to a cryogen manifold. The system may detect a cooling of the cryogen manifold caused by filling of another cryogen vessel with cryogen, and responsively initiate its own filling process. Thus, a number and duration of venting instances is reduced. Before filling a cryogen vessel with cryogen, a fill control system may vent filling lines and/or a cryogen manifold to limit introduction of warm fluid into a cryogen vessel. By determining when another fill control system has already initiated venting of the cryogen manifold (indicated by cooling of the cryogen manifold as cryogen flows), a fill control system reduces the amount of venting that it must perform prior to filling its associated cryogen vessel from the cryogen manifold.

A system includes a storage tank and a feed line that supplies a compressible fluid from a high-pressure source to a plurality of fluid lines in fluid communication with the storage tank. The plurality of fluid lines includes a first fluid line having a first inner diameter sized to create choked flow conditions of the compressible fluid in the first fluid line at an outlet of the first fluid line and a second fluid line having a second inner diameter greater than the first inner diameter. The system further includes a first valve in fluid communication with the second fluid line and a control circuit in electronic communication with the first valve. The control circuit actuates the first valve to control a flow of the compressible fluid through an outlet of the second fluid line.