Flight Dynamic and Aerothermodynamic Conceptual Design of a Bent-Nose Biconic RV Bus for Atmospheric Entry From Low-Earth Orbit

摘要

Reported herein are the results of a conceptual design-level analysis of a biconic re-entry vehicle (RV) designed for atmospheric entry missions from low-earth orbit. In the current application, the RV serves as a carrier bus for delivery of a classified payload from a circular 170-nautical mile earth orbit to a point 2000 nautical miles downrange from deboost Altitude and velocity at the targeted position was specified as 120 KFT and Mach 6, respectively. A bent-nose biconic RV configuration was selected since this particular shape exhibits a relatively low ballistic coefficient (on the order of 100 to 200 psf) and a maximum lift-to-drag ratio of 1.6. The low ballistic coefficient reduces the severity of the aerodynamic heating environment while the moderately high lift-to-drag ratio provides adequate maneuver and trajectory shaping capabilities within the earth's atmosphere. The post-deboost trajectory consists of a 1500 nautical mile Keplerian Phase followed by a 500 nautical mile dive/pull-up/run-in Entry Phase flight profile resulting in a total flight duration of 557 seconds. RV mass at entry is 5500 pounds. The thermal protection system (TPS) consists of carbon phenolic on the RV nose, ESM 1004 LPS on the windward fore and aft conical frustums, and SAM on the vehicle upper surface and base region. Highlighted in the report are the flight dynamic, aerothermodynamic, and TPS performance prediction methodologies developed and applied in support of the RV bus conceptual design process.