Ascent trajectory optimiztion for the first stage of a two - stage - to - orbit reusable launch vehicle with load factor constraint during re - entry

The main objective of using reusable launch vehicle is to minimize the operational cost of launching satellites into outer-space. This is achieved by flying back the launch vehicle back to launch station or to any designated landing site, thus the vehicle can be recovered and reused. This paper discusses about optimizing the steering angle (θ₂) at burnout during ascent phase for the first stage of a TSTO launch vehicle and thereby to maximize the velocity at zero flight path angle, subjected to the constraint involved in re-entry. Since optimization of ascent phase is performed by considering the re-entry constraint, the optimization is carried out in multi-disciplinary optimization framework.