Fallskärmshopp

År 1960 åker Joe Kittinger med en helium-ballong upp till 3 mils höjd. Hans vante har gått sönder och han fryser; det är -110 grader (Fahrenheit förstås). Han hoppar och blir den förste människan i rymden. Lufttrycket är bara c:a 1 kPa. (Vid havsytan är lyfttrycket c:a 100 kPa och luftens densitet är ρ ≈ 1.25 kg/m³.)

Så här skrev Guardian weekly (13 juni 1999) om hans hopp:

Joe Kittinger looks like a cowboy but he's an airforce colonel and the first man in space. In 1960 he went up 20 miles in a helium balloon, a little silver bubble in the blackness. Half-way there his glove split, allowing deadly cold in. "I didn't tell my flight surgeoun because I didn't want to worry him. I felt reasonably certain I could survive." At 103,000 ft he said a silent prayer - it had to be silent, there was no air - and jumped. "I fell face to earth for a little ways and I really had no sensation of falling because I had no visual reference. I turned over on my back about this time and I looked up and the balloon was racing into the heavens, just flying away. What it was was the balloon was standing still and I was the one that was falling." He fell at the speed of sound but made no sound. No air rippled his space suit. After four minutes, he reentered the atmosphere. He hit the desert and thought it looked like the garden of Eden. Someone patted his cheek.