the go-ahead on Sunday morning with the cooperation of the weather. Baumgartner was carried up into crystal clear skies by a gigantic balloon, which measured 30 million square cubic feet and whose skin was one-tenth the thickness of a sandwich bag. At the bottom of the balloon was a capsule, in which Baumgartner sat in his suit. As he reached the desired height, Baumgartner went through a checklist of 40 items with his mentor Joe Kittinger, the previous holder of the highest altitude manned balloon flight. There was some concern that a heater for his visor was not working, causing his visor to fog. “This is very serious, Joe,” he told Kitttinger. “Sometimes it’s getting foggy when I exhale. ... I do not feel heat.” But they decided to go ahead, watched by a record 8 million people as the jump was streamed live on YouTube. The two-and-a-half-hour journey upwards, during which the curvature of the Earth became visible and the skies gradually turned black, was matched with a rather more rapid descent. Three cameras attached to Baumgartner’s suit recorded his free-fall of just over four minutes – which failed to break the existing free-fall record for duration – and then the parachute opening. The success of the mission, and of the suit, raises the prospect that astronauts might be able to survive a high altitude disaster of the type that struck the space