Passive zero-boil-off storage of liquid hydrogen for long-time space missions

The technology of the storage of liquid hydrogen and liquid oxygen is one of the key technologies that decide whether hydrogen can become the new energy for space science missions in the future. In the current study, a storage system for space missions will be designed without good thermal insulation system around the liquid hydrogen tank, and allow the radiation heat to leak into the space environment from the tank. The theories of heat conduction and radiation heat transfer have been utilized to study the rate of heat absorption for a hydrogen storage tank in space. The model has been simplified by taking several aspects of heat transfer into account, which contains the radiation heat into the storage tank from the sun and spacecraft, the radiation heat into the space environment from the tank, the heat conduction into the tank from the support structure, and the heat conduction into the tank from the liquid oxygen tank. By establishing the function relationship between the rate of heat absorption and the temperature of the liquid hydrogen and oxygen tank, we can demonstrate that the liquid hydrogen can be stored within two years without evaporation.