Nowadays space access is guaranteed by expandable launchers which, once the mission has ended, can’t be reuse for the successive mission. This involves a big waste of resources and necessarily high costs. One solution to reduce the costs and gain flexibility in space missions is the use of reusable or partially reusable vehicle. Reusable launch vehicles are facing a great evolution in the last years, and in particular reusable two-stage-to-orbit have been identified from many studies as the vehicle of the future in the aerospace field because they have the capability of delivering a wide range of payload in orbit at low cost, with a greater flexibility using conventional airports and infrastructures even gaining many operative and legal advantages.