This paper presents open challenges and perspectives of propellant management for crewed deep space exploration. The most promising propellants are liquid hydrogen and liquid methane, together with liquid oxygen as an oxidizer. These fluids remain liquid only at cryogenic conditions, that is, at temperatures lower than 120 K. To extend the duration of space exploration missions, or even to enable them, the storage and refueling from a cryogenic on-orbit depot is necessary. We review reference missions, architectures, and technology demonstrators and explain the main operations that are considered as enablers for cryogenic storage and transfer. We summarize the state of the art for each of them, showing that many gaps in physical knowledge still need to be filled. This paper is based on recommendations originally proposed in a White Paper for ESA’s SciSpacE strategy.

本文提出了载人深空探索推进剂管理的开放挑战和前景。最有前途的推进剂是液氢和液甲烷，以及作为氧化剂的液氧。这些流体只有在低温条件下（即温度低于 120 K 时）才能保持液态。为了延长太空探索任务的持续时间，甚至为了实现这些任务，需要在轨低温储存库进行储存和补充燃料。我们回顾了参考任务、架构和技术演示器，并解释了被认为是低温存储和传输推动因素的主要操作。我们总结了它们各自的最新技术，表明物理知识上的许多空白仍然需要填补。本文基于 ESA SciSpace 战略白皮书中最初提出的建议。