Liquid hydrogen tests of a sub-scale launcher upper stage feed line evaporation cooler

Kurzfassung

Propellant conditioning is a challenge for the development of cryogenic upper stages with re-ignitable main-engines. The VINCI engine needs for its operation propellant under specific conditions w.r.t. pressure and temperature to avoid cavitation inside the propellant pumps. After long ballistic phases the temperature of the propellant can increase to the respective saturation temperature of the tank pressure due to radiative solar heating. By means of the proposed feed line evaporation cooler 1stly the usual release of the tank pressure for thermally conditioning the propellant and 2ndly the follow-on re-pressurization of the tank with Helium can be avoided. Furthermore, this feedline evaporation cooler allows cooling only the propellant amount that is actually consumed by the engine. In this paper the design of the EC test unit, the LH2 test bench and respective results of the tests performed with LH2 will be presented in order to demonstrate the technology's capability and readiness. Additionally, a possible design and assembly on the A6 upper stage propulsion module is suggested.