Since the birth of the space industry, the topic of re-usability has been taken into consideration without ever being able to be truly systematically applied to the development of fully reusable spacecrafts. Maintaining an efficient mass ratio for reusable vehicles is a very hard engineering challenge. In fact, launching relative small payload into orbit requires a big quantity of mass propellant, making it inefficient and expensive: re-usability requirements worsen it by adding further subsystems inert mass. However, today, the space industry is witnessing a renewed interest in the development of fully reusable space systems thanks to the to the economic advantages and the increase in safety and environmental sustainability.