Multidisciplinary Optimization in the Design of Future Space Launchers

As industrial prime contractor ASTRIUM Space Transportation is responsible for the design of space launchers. A space launcher is a complex system, requiring contributions from many disciplines. In this chapter we will endeavour to limit ourselves to the launch vehicle design problem, which proves to be a multidisciplinary optimization problem. The mission of a space launcher is to place a payload in a given orbit expressed as a speed at a given point. The payloads are classically near Earth artificial satellites, solar system exploration probes or spacecraft able to transport people. The orbit required depends on the payload's missions. Low orbits are often used for Earth observation missions, geostationary orbits are the preferred orbits for communication satellites. By the term launcher, we therefore understand the vehicle that places a payload in orbit. A launcher's objective is to communicate high energy to the payload with a gain in altitude (potential energy) and a gain in speed (kinetic energy). To obtain high energy in both the atmosphere and in vacuum, the technology adopted is the rocket motor, which is based on the action-reaction principle with the continuous ejection of fuel.