Rocketdyne RBCC Concept Development

Rocketdyne is pursuing the conceptual design and development of a Rocket Based Combined Cycle (BBCC) engine for booster and SSTO, advanced reusable space transportation systems under the Advanced Reusable Transportation Technologies contract with NASA Marshall Space Flight Center. The Rocketdyne concept is a fixed geometry integrated rocket, ramjet, scramjet which is hydrogen fueled and uses hydrogen regenerative cooling. Vision vehicle integration studies have determined that scramjet operation to the range of Mach 10 to 12 has high payoff for low cost reusable space transportation. Rocketdyne is internally developing versions of the concept for other applications in high speed aircraft and missiles with hydrocarbon fuel systems. A subscale engine ground test program is underway for all modes of operation from takeoff to Mach 8. High altitude rocket tests will only be completed as part of the ground test program to validate high expansion ratio performance. A unique feature of the ground test series is the inclusion of dynamic trajectory simulation with real time Mach number, altitude, engine throttling, and RBCC mode changes in a specially modified freejet test facility at GASL. Preliminary cold flow air augmented rocket and all rocket test results have met program goals and have been used to integrate all modes of operation in a single combustor design with a fixed geometry inlet for design confirmation tests. A water cooled subscale engine is currently being fabricated for test during the early part of 1998.