Daredevil Felix Baumgartner rode in a capsule pulled up by a helium balloon to 13.6 miles (21.8 km) above the Earth's surface before balancing on the edge of the pod and launching himself off.

At around 120,000 feet, on the fringes of space, the air is so thin that a falling human body would travel fast enough to exceed the speed of sound. A skydiver, properly equipped with pressurised suit and a supply of oxygen to protect against the hostile elements, could feasibly jump from that height and, about 30 seconds later, punch through the sound barrier…

He is aiming to break the current world record of a 19.5-mile (13.3-km) plunge by jumping 23 miles (37 km) this summer.