Abstract: During the separation stage of Two-Stage-to-Orbit (TSTO) vehicles, intense unsteady aerodynamic disturbances occur between the orbiter and the booster due to the presence of complex shock wave systems. To ensure the safety and relia-bility of the separation process, it is essential to conduct a comprehensive and precise design and evaluation of stage separation schemes at high Mach numbers. Based on numerical virtual flight technology coupled with aerodynamics-motion-control, this paper performs an in-depth analysis and comprehensive selection of separation preparation attitude, separation mechanism, and control strategies for the orbiter- booster assembly. The results indicate that at high Mach numbers, an extremely complex wave system topology exists between the two stages, which evolves dynamically with their relative positions, leading to highly nonlinear aerodynamic characteristics for the orbiter. Through a comparative study of multiple configurations, a final separation scheme was established: the orbiter adopts a 0deg separation attitude angle and utilizes a telescopic strut separation mechanism combined with integrated control of aerodynamic surfaces and thrust vector control. Simulation results demonstrate that, compared to the initial scheme without active control or param-eter optimization, the proposed separation scheme increases the relative normal load factor between the orbiter and the booster by 40.5% at the moment of separation, reduces the time required for the orbiter to exit the shock interference zone by 16.0%, and increases the separation attitude angle by 4.1deg. The design achieves controllable separation of the orbiter and significantly enhances the safety of the two-stage separation process.

Key words: Two-Stage-to-Orbit vehicle, Aerodynamics-motion-control coupling, Numerical virtual flight, Stage separation scheme, Overset mesh