Up until 2003, the only people that could fly as high as James May flew on the U-2 were passengers on the Concorde SST, which could fly as high as nearly 60,000 feet at times. But pretty soon, once Virgin Galactic starts its space flights, passengers will fly as high as 328,000 feet, right at the real beginning of space.
I’m no rocket scientist, but I don’t think the “thinness” of air in space is what can kill you in an instant. Any science buffs out there?