Unity is a sub-orbital rocket and cannot achieve the velocity or altitude required to maintain its position in space or circle the earth. It is carried into space using a bigger rocket up to 15 km and can achieve a maximum height of 90 km.

It has a unique feather mechanism to self-stabilize its fall while gliding back to earth.

Sir Richard Branson, the billionaire entrepreneur who owns Virgin Galactic, boarded his rocket for its maiden space voyage, debuting private space tourism and beating Elon Musk and Jeff Bezos to the private space race.

• Unity, the rocket plane with two pilots, flew the billionaire to ...