Progress in the Design of a Reusable Launch Vehicle Stage

Abstract

The German future launcher technology research program ASTRA investigates in its system study two types of partially reusable launch vehicles. This paper describes one of those concepts, a reusable first stage designed for a near term application with a heavy lift launcher. The attached reference expendable space transportation system is a future Ariane 5 with cryogenic core and upper stage, but skipped solid rocket boosters. The design of the reference liquid fly-back boosters (LFBB) is focused on LOX/LH2 propellant and a future derivative of the Vulcain rocket motor. After achieving a convergent design in the first iteration loop, a more detailed level of investigation has been started. This includes the ascent control requirements on the booster TVC system, a refinement of the aerodynamic shape, and the preliminary mechanical lay-out of body and wing structure. All major results are presented, and used in an update of the mass budget, as well as trajectory simulations and optimizations for ascent and reentry.