Michael PALUSZEK, Christopher GALEA, Stephanie THOMAS
DOI Number: 10.60853/xy7j-ax27
Conference number: HiSST-2024-0072
With the expansion of space commercialization, the need for rapid access to space is increasing. This paper expands on the authors’ past work on the Space Rapid Transit vehicle. It is a two stage to orbit vehicle that takes off horizontally and lands horizontally. It is sized to carry 500 kg to an ISS orbit. It is fully reusable. The first stage is powered by a hydrogen-fueled turboramjet with a subsonic rotating detonation combustor. The second stage uses liquid hydrogen and liquid oxygen propellants. The stages separate using their reaction control systems. The new results in this paper cover the control of the two vehicles in the atmosphere and the optimization of the separation Mach number and altitude. The control system transitions from all aerodynamic to mixed reaction control and aerodynamic control. The control is partitioned into torque and force demand and actuator, thruster or aerodynamic, and force and torque distribution. This results in a very robust controller. Nonlinear plant inversion is used to implement the core controllers. The first and second stage will be addressed, as will control during separation. The second major contribution is a selection of the separation altitude and Mach number using the demand on the first stage turboramjet and on the airframe as the criteria. The first stage engine is an accelerator but even so it will experience high thermal and dynamic stresses. The resulting two-stage vehicle is demonstrated in numerical simulations. The simulations go from takeoff roll to orbit. The trajectory for the rocket second stage is presented.