Propulsion Systems Definition for a Liquid Fly-back Booster

This paper describes the final design status of a partially reusable space transportation system which has been under study for more than five years within the German future launcher technology research program ASTRA. It consists of dual booster stages, which are attached to an advanced expendable core. The design of the reference liquid fly-back boosters (LFBB) is based on LOX/LH2 propellant and a future advanced gas-generator cycle rocket motor. In focus are the four different propulsion systems and the main propellant feed and pressurization system