Studying the landing of the reusable first stage of the Cyclone-5 space launch vehicle on a maritime landing platform

The development of reusable launch vehicles allowing for the recovery of their components (particularly the fi rst stages) is a logical step in the evolution of modern space rocket technology. Yuzhnoye State Design Offi ce, as one of the leading designers of space rocket technologies, engages in research eff orts concerning this issue. For example, a conceptual design of the Cyclone-5 space launch vehicle with a reusable fi rst stage was devised. A dynamic rocket landing using the primary propulsion system and specialpurpose legs was chosen as the recovery method for the fi rst stage. Considering the diffi culties in selecting landing areas for the fi rst stage, making it land on a seagoing platform in the sea seems reasonable. Such a platform may sail to the assigned location in advance and transport the fi rst stage after landing as close as possible to the space fl ight facility to prepare it for the next fl ight. This paper shows the potential designs of the fi rst stages of space launch vehicles and the seagoing landing platform. It also specifi es the parameters of such a platform and the ambient (environmental) factors to be considered when studying the landing of a space rocket’s fi rst stage. This paper also describes the study procedure and simulates some scenarios of the joint motion of the fi rst stage and the landing platform. The values and ratios of various parameters were determined from the analysis of the dynamics, and some relations were derived. The output of this work will be useful in proceeding to the practical realization of a space launch vechicle project with a reusable fi rst stage.