A billionaire kicked off the first private spacewalk Thursday, teaming up with SpaceX on the daring endeavor hundreds of miles above Earth. Tech entrepreneur Jared Isaacman and his crew waited until their capsule was depressurized before popping open the hatch. Isaacman was to be the first one out, aiming to join a small elite group of spacewalkers who until now had included only professional astronauts from a dozen countries. All four on board donned SpaceX’s new spacewalking suits to protect themselves from the harsh vacuum. They launched on Tuesday from Florida, rocketing farther from Earth than anyone since NASA’s moonwalkers. The orbit was reduced by half — to 458 miles (737 kilometers) — for the spacewalk.