Return to Launch Site Trajectory Options for a Reusable Booster Without a Secondary Propulsion System

Abstract

This paper reports the findings of a continuing study to examine the capabilities, flight dynamics, and operability of a new launch system predicated on a Reusable Booster System. This effort is part of the ongoing U.S. Air Force Future-responsive Access to Space Technologies (FAST) program. The authors considered a multi-stage launch vehicle with a reusable wing-body first stage and two expendable upper stages. The baseline propellants were selected to be LOX/RP-2 for all stages. A complete, Level 1 multidisciplinary conceptual systems assessment was performed on a baseline launch vehicle design and numerous trade study configurations to determine the impact to key performance metrics such as size, empty mass, and gross mass. The trade study variables of interest were the staging flight path angle, staging dynamic pressure, staging Mach number, and post-staging RTLS pitch over direction. Findings indicate that while minimal impact was seen for the top-level vehicle metrics like size, gross weight, and dry weight, there were more significant impacts to the vehicle's actual flight environment in terms of normal force loads, peak heat rate, and total heat load. Numerical results for all vehicle results from this effort are reported.

Reusable Launchers: Development of a Coupled Flight Mechanics, Guidance, and Control Benchmark

“…In recent years, several studies [2][3][4][5][6] have addressed the problem of RLV performance optimisation. These are mostly focused on the application of multi-disciplinary optimisation (MDO) methods to determine L&R trajectories that allow delivering the highest payload while fulfilling competing mission and aerothermal load requirements.…”

“…In parallel, several programmes and studies have been established to study and further reusability. Most of these studies [2][3][4][5][6] are focused on the application of a multi-disciplinary optimisation (MDO) framework to determine combined launch and recovery (L&R) reference trajectories, staging conditions and vehicle configurations that allow to reach the highest payload while keeping aerodynamic and thermal loads at reasonable levels. Although the MDO approach is extremely valuable for preliminary system sizing, it is not well suited to study the existing couplings between flight mechanics, guidance and control (G&C).…”