EVOLUTION OF A BLENDED LIFTING BODY FOR THE ORBITAL SPACE PLANE

摘要

NASA's Orbital Space Plane (OSP) program incorporated elements of past efforts such as the Space Transportation Architecture Study (STAS), Crew Return Vehicle (CRV), and Space Launch Initiative (SLI). Significant goals of these efforts were to improve safety, reduce the cost of crew transportation to space, and to provide robust crew rescue and crew transfer capability for the International Space Station (ISS). NASA's requirements for OSP were assessed and evaluated, and several critical design drivers were derived: number of crew, mission duration, launch vehicle throw weight, vehicle lift efficiency, flight rate, reusability, and ascent abort and emergency return capabilities. NASA Langley Research Center's HL-20 shape was used as an initial reference design to better understand and assess the impact of NASA requirements as they were flowed down to the vehicle subsystem level. Configuration and aerodynamic trades were conducted to optimize the performance of the OSP in response to these requirements. Most importantly, issues of volumetric efficiency, high L/D for cross range, low wing loading for reduced landing speed, and passive stability for all abort conditions were addressed. As the optimization process continued, the HL-20 initial reference shape eventually evolved into the Blended Lifting Body (BLB). The BLB combines volumetric efficiency with superior aerodynamic qualities and was designed to launch vertically and land horizontally. The BLB design offers an optimized configuration with excellent aerodynamic performance and may have many other flight applications. This paper discusses the evolution process, design solutions, and features of the configuration used during the development of the BLB for the OSP program.