Ilja Müller

Transpiration-Cooled Ceramic Thrust Chamber Applicability for High-Thrust Rocket Engines

The development of ceramic rocket engine thrust chambers at the German Aerospace Center (DLR) currently concentrates on designs of self-sustaining, transpiration-cooled, fiber-reinforced ceramic rocket engine chamber structures. This paper discusses characteristic issues and potential benefits introduced by this technology. Achievable benefits are the reduction of weight and manufacturing cost, as well as an increased reliability and higher lifetime due to thermal cycle stability. This paper discusses the current status of DLRs ceramic thrust chamber technology and potential applications for high thrust engines. The test results of DLRs ceramic thrust chamber project KSK are used for a rough approximation of the performance of high thrust applications. Based on the KSK test results an extrapolation is performed. c*-efficiency and geometrical scaling effects are taken into consideration. Due to favorable scaling effects, high thrust applications will profit by all benefits of the discussed technology, while avoiding the most significant performance drawbacks.

Structural Investigations on Cryogenically Operated and Transpiration Cooled Fiber Reinforced Rocket Thrust Chambers

This paper will give a subsumption of the structural implementation of an integrated fiber reinforced rocket thrust chamber design, which took in the meanwhile more than one decade of development effort. Of particular interest in this case is a hybrid design approach showing Ceramic Matrix Composits as high temperature inner liner materials and a covering light weight Carbon Fiber Plastic Housing, whereas these principally different material components are joined by metallic flanges at the front edges in an extensively decoupled design philosophy, excluding compulsive loads as far as possible. In 2010 the long and intensive experimental work led into a test campaign at the European Research and Technology Test Facility P8 at DLR-Lampoldshausen using for the first time the fully integrated chamber design under cryogenic high performance conditions, using LOX/LH2. In this campaign the structural concept could be proved completely under all structurally relevant parameters. With respect to the demonstration of the system efficiency under optimized operational flow parameters a further test campaign early in 2012 had been performed at the recently renewed local P6.1-test bench. The paper discusses predominantly structural design aspects.

Innovative Small Launcher

The market for small satellites is expected to increase substantially in the coming years, but there is little capacity to launch them affordably. No operational dedicated launcher for small satellites exists today. Small satellites, launched as secondary payloads, are entirely dependent on the constraints set by the primary payload, such as launch date and target orbit. Launch costs of less than €50,000 per kg of payload are required in order to directly compete with piggy-back ride shares. With a dedicated launcher a higher cost per kg can be accepted for payloads which need to be delivered timely and accurately to a desired orbit.