APPROACH AND LANDING TRAJECTORY OPTIMIZATION FOR THE SIERRA SPACE DREAM CHASER® SPACEPLANE

The Dream Chaser® is a reusable lifting body spaceplane designed by Sierra Space to transport cargo and people to and from low earth orbit, reenter the atmosphere in a benign, low-g environment, and land horizontally on a conventional runway. The atmospheric phase of flight, known as Entry, Descent and Landing (EDL), consists of three individual flight segments: Entry, Terminal Area Energy Management (TAEM), and Approach & Landing (A&L). This paper describes an enhanced parameterization of the A&L altitude profile geometry and a corresponding methodology to fully specify its parameters in a way that ensures continuity through second derivatives with the specification of a minimum set of parameters. This improved trajectory specification methodology in conjunction with the inclusion of an ensemble of dispersed plants in the optimization processes results in an A&L trajectory optimization tool that is significantly more robust and capable than previous implementations.