Next Generation Space Transportation System using Conventional Expandable Launch Vehicles

This paper summarizes the results of a conceptual design study of a Space Transportation System (STS) that could fulfill the need low cost and frequent access to space. The concept is based on a reusable orbiter that can be launched using conventional expendable launch vehicles. The vehicle is designed primarily to carry crew and supplies to low Earth orbit (LEO) and back. The STS concept uses a twostage expendable Ariane 5 as the primary launcher, having the minimal capability of delivering 18 tons of payload to LEO. Study has been made to accommodate the vehicle to different expendable launchers by the use of a universal adapter. Propulsion is provided by a Vulcain main cryogenic stage, two solid rocket boosters and an upper stage Aestus engine. The vehicle can be operated manually or autonomously and is fully reusable. A conceptual design project determined the vehicle gross weight to be approximately 21,600 kg with a dry weight of 14,300 kg. Weight and operating cost assumptions were made throughout the design process for first generation reusable system that might be deployed in the next 10 years time. Drawings, geometry and weights of the concept are included.