Liquid Fuel Rocket; Expendable Launch System A COMPARATIVE ASSESSMENT OF VARIOUS METHODS FOR RECOVERING REUSABLE LOWER STAGES

摘要

The numerous attempts to create a reusable space transportation system have led to a division of this general direction into those of reusable spacecraft development on the one hand and of reusable lower stage development on the other. Whilst the first direction, which led to the creation of space shuttles, had no direct regard to the realization of reusable launch vehicles, the second direction is currently one of the most promising ways to enhance the economic efficiency of launch vehicles in the nearest future. The methods for recovering lower stages which were either proposed or just realized, are described in the paper. They are divided into groups by the concepts that are used. Thus, there are methods which are using 'passive' devices for an unguided landing onto the Earth's surface without the provision of an accurate landing onto a chosen spot, methods which are using the Earth's atmosphere as a source of aerodynamic support and atmospheric air as an oxidizer for the just separated stage's flight back to a required spot, and lastly, methods which are based on braking the stage by its own main rocket engine. The advantages and shortcomings for each of the methods are discussed in order to use them for a comparative assessment. From this recommendations are made for their use in specific applications in various types of the partially reusable launch vehicles.