Performance of a Feedback Method with Respect to Changes in the Air-Density during the Ascent of a Two-Stage-To-Orbit Vehicle

Abstract

In recent years there has been a lot of research with respect to the so-called Sänger model: the corresponding aerospace system consists of two hypersonic airplanes, where the smaller one initially is fastened on top of the lower vehicle. This compound is to be launched horizontally by means of the propulsion system of the lower airplane which takes the upper part to a certain altitude. At this point the two stages separate, the lower stage returning to the ground, while the upper stage continues its ascent to an Earth-orbit, capable of a later re-entry manoeuvre similar to the Space-Shuttle orbiter. For more details see Kuczera et al. [5]. The research efforts devoted to this Two-Stage-To-Orbit (TSTO) system were concentrated both on the propulsion system and the trajectory optimization (Bulirsch,Chudej [2]). In the latter paper a-priori solutions or nominal trajectories for prescribed physical data have been given.