The European Spaceplane programme HERMES is presently in the Phase B stage, and detailed system and subsystem layouts and performance calculations are being performed.
The defined spaceplane configuration and the proposed mission scenario have resulted in a baseline ECLSS configuration to meet set requirements based on european technology and optimal spaceplane performance.
The short mission duration implies non-regenerative processes similar to the Shuttle ones, but on the other hand a full compatibility with the european COLUMBUS programme, and thus indirectly with the International Space Station, is also required. The selected ECLSS concept is well within european capabilities, and it also permits a growth into more independant european missions at the turn of the century with the introduction of regenerative processes e.g. for water supply and atmosphere revitalization for long duration missions. The particular combination with a fuel cell system for electrical power supply does impose special considerations for the water management.
The relative size of the spaceplane makes it very mass and power critical and special efforts are being made to reduce these characteristics.
This paper gives an overview of the present ECLSS baseline and potential options to meet anticipated system improvement goals, in particular a low mass and power configuration.