Survivability of emergency escape from a simulated space shuttle entry trajectory

As a component of the NASA SVTI on reusable launch vehicles, the University of Maryland Space Systems Laboratory in 2002 began an investigation of the feasibility of providing crew escape options from the Space Shuttle or a future reusable launch vehicle throughout the entry profile. MATLAB(TM) code was written to simulate a typical winged vehicle entry trajectory. The code was extended to simulate ejection trajectories for a ballistic capsule on a minute-by-minute basis throughout the original entry profile. The ejection trajectories, representing instantaneous change in vehicle aerodynamic properties, were studied for theoretical survivability and were analyzed to determine the optimum design characteristics for an escape vehicle. The results indicate that escaping from a reentering vehicle is survivable for most of the trajectory, with the exception of a small period right around maximum aerodynamic pressure.