Sky Diver Plans Record-Breaking 120,000-Foot Jump From Stratosphere

A skydiver is set to become the first person to break the sound barrier during a free fall by leaping from  on the edge of space.

Sometime in August of this year, skydiver Felix Baumgartner intends to climb into a capsule suspended beneath a helium balloon, rise 23 miles above Roswell, New Mexico, open the capsule door, and jump out. On the 120,000-foot free fall—the longest ever attempted—he will face temperatures as low as –70°F and speeds of more than 700 miles an hour, becoming the first person to accelerate through the sound barrier without a craft. At the outset of the project, dubbed Stratos by its sponsor, Red Bull, no high-altitude full-pressure suit had ever been built specifically to withstand this kind of controlled free fall. Engineers at the David Clark Company, which builds full-pressure suits for NASA and the Department of Defense, spent four years developing one. Baumgartner’s jump will be the first live trial at Mach speeds.

Suit: It has four layers. The outer layer is made of Nomex, a fire-retardant material that will also act as an insulator. Under the Nomex is a mesh restraint, which holds a gas-filled bladder. The innermost layer is a breathable liner. Once pressurized, the suit will become rigid. Its vertical orientation will help Baumgartner maintain delta position (head down, feet up) throughout his free fall—crucial if he is to avoid a flat spin.

Pressure System: To avoid decompression sickness, hypoxia and tissue damage—all risks associated with drastic changes in atmospheric pressure—Baumgartner will be breathing pure oxygen, and his suit will maintain an internal pressure of 3.5 psi. As he falls, an aneroid valve and a pair of diaphragms will regulate the suit’s internal pressure. When he hits 35,000 feet, it will depressurize, giving him greater mobility.

Chest Pack: The technology hub of the suit, the chest pack contains a voice transmitter and receiver; a high-definition video camera with a superwide 120-degree view; an accelerometer; an inertial-measurement unit that reports pitch and angle; and twin sets of lithium-ion batteries, one to power the visor’s de-icing system and one to power the chest pack itself.

G-Meter: The jump will begin in the stratosphere, where falling objects, less hindered by air density and friction, tend to spin. But a violent spin could whirl Baumgartner into a G-force-induced loss of consciousness, called G-loc, and even rattle him to death. As a precaution, he will wear a G-force meter on his wrist. If it reads 3.5 or more Gs for a period of six seconds, the meter will trigger the release of a three-foot drogue parachute designed to stabilize spins.