From the article:
"632 miles per hour broke the land speed record, making Stapp the fastest man on earth. And 46.2 G’s was the most any human being had ever willingly experienced. Prior to the test Nichols had real doubts about whether it was actually survivable. It turned out it was, although Stapp paid a severe penalty. He suffered a complete red out. “His eyes had hemorrhaged and were completely filled with blood,” Nichols remembers, his voice cracking. “It was horrible. Absolutely horrible.” The image of Stapp’s crimson visage haunts Nichols to this day."
The story of Murphy's Law: The Fastest Man on Earth