Comparative Analysis of Two-Stage-to-Orbit Rocket and Airbreathing Reusable Launch Vehicles for Military Applications

摘要

The Department of Defense (DoD) has identified operationally responsive, low-cost access to space as vital to maintaining U.S. military supremacy. Reusable Launch Vehicles (RLVs) will allow the U.S. to keep a technological advantage over our adversaries, and advances in airbreathing propulsion technology have made it feasible for use in space launch vehicles. This study considers two-stage-to-orbit (TSTO) RLV configurations, each using combinations of propulsion including pure rocket, pure turbine, rocket-based- combined-cycle (RBCC), and turbine-based-combined-cycle (TBCC) for the both stages. This study explores the advantages of airbreathing propulsion in those key areas when compared to a baseline configuration, using vehicle empty mass and vehicle wetted area as the primary figures of merit. Results show that a vehicle using airbreathing propulsion on the orbiter stage has a lower vehicle empty mass and wetted area than a pure rocket, and allows the RLV to gain the advantages of using airbreathing propulsion. The requirements used for this comparison are: 1) a payload module requirement of 20,000 pounds; 2) a 100x100 nautical mile, 28.5 lat. Easterly orbit and return; 3) use of hydrocarbon fuels (RP-1 and/or JP-7) and liquid hydrogen (LH2); and 4) use of liquid oxygen and/or air as oxidizers. ASTROX Corporation's Hypersonic System Integrated Design Environment (HySIDE) code is used as the design tool throughout the study.