Operational Entry Spacecraft Using Airbreathing Propulsion 680369
The application of air breathing turbofan engines to a variable geometry, lifting, entry spacecraft provides a Cruise-spacecraft having increased operational flexibility. This spacecraft can accomplish a high performance, 3000 nautical mile lateral range mission, by combining the glide available from its medium hypersonic L/D (1. 7 to 2. 3) with subsonic cruise in the atmosphere. In this application, it excels low L/D spacecraft requiring orbit maneuvers to enhance lateral range. It is competitive with high L/D spacecraft while avoiding some of their advanced aerodynamic and thermal protection system technologies. For the reduced lateral range logistic mission, the spacecraft can utilize the “liquid L/D” principle to reduce cruise fuel and replace it with additional cargo. The Cruise-spacecraft is a medium L/D, slim, lifting body which uses an ablative lower surface and a radiative upper surface for protection during entry. At subsonic speed, the wings and air breathing cruise engines are deployed from within the thermally protected body. Powered, aircraft-like landing performance is available at minimum penalty. The spacecraft can recover from a down-range launch abort by cruising back to the launch site with the assistance of in-flight refueling. Large water based recovery forces are avoided. The aircraft characteristics of the concept make it readily adaptable to early development/training versions which can take off horizontally. The variable geometry arrangement with air breathing fly-back engines is readily adaptable to reusable first and second stage launch vehicles.