From A Risky Spacewalk To The Top of Mount Everest, Popular Science
"Parazynski just seems to be wired differently than many of us. His pursuit of extreme environments seems to know no bounds. In addition to being an astronaut (who has completed five space shuttle missions, seven space walks and spent 57 days in space), Parazynski is also a medical doctor, scuba diver, pilot, speaker and mountain climber he's the only astronaut to summit Mount Everest. He gives his parents and some key life events credit for his adventurous spirit. "It's hardwired in my blood," he says."