Return to Launch Site Trajectory Aeroheating for a Resuable Booster

For the past few years, the Air Force has been studying using a reusable booster stage to meet access to space needs for Operational Responsive Spacelift. After staging, the current desire is for the booster to return to its launch site. This paper will go over two trajectory methods of returning the booster after staging, using turbine engines for cruise following downrange ballistic flight and using the main rocket engines to reverse the horizontal velocity. One main difference between these two concepts is the aeroheating environment that corresponding vehicles will encounter. This paper presents trajectories designed to minimize the cost of a hybrid launch system (reusable booster and expendable upper stage) and corresponding aeroheating of the booster. These results clearly show that using the main rocket engine to reverse horizontal velocity, known as the rocketback method, allows the vehicle to undergo a milder heating environment.