Ascender is a small sub-orbital spaceplane designed to use existing technology and to pave the way for later vehicles on our development sequence. Ascender is specifically designed to generate spaceplane revenues at minimum development cost and risk, and thereby to be attractive to private-sector investment. Ascender carries one pilot and one passenger or experiment. The passenger remains strapped in his/her seat during the flight. Ascender takes off from an ordinary airfield using its turbo-fan engine and climbs at subsonic speed to a height of 8 km. The pilot then starts the rocket engine and pulls up into a steep climb. Ascender has a maximum speed of around Mach 3 on a steep climb and can reach a height of 100 km. [Bristol Spaceplanes Limited. bristolspaceplanes.com/projects/ascender/]