The nozzles are very important parts of the propulsion systems which will equip the future space plane. They are the location where the burned gases by the motors are expanded to supply the thrust to the vehicle during its ascent toward space.

These nozzles use the rear part of the spacecraft fuselage, also called afterbody, as an expansion ramp. This original concept allows self adaptation of the outlet section.

Performances are evaluated by numerical simulation on a computer. The computations facilitate the understanding of the nozzle behaviour and allow to optimize aerodynamic shapes. Models are tested in wind tunnels at speeds above Mach 6 and accurate measurements provide validation at real flight speeds.