Scott Parazynski is the first and only person to have both flown in space and summited Mt. Everest. He's also a physician, a scientific diver, a commercial pilot, and a luge competitor for the 1998 U.S. Olympic team trials. Now, he's the founder and CEO of Fluidity Technologies, a start-up that makes a one-handed drone controller for precision operation. Parazynski says being an entrepreneur is his greatest challenge yet.