Last season world-class mountaineer and Everest guide Adrian Ballinger, accompanied by National Geographic photographer Cory Richards, chronicled his attempt to summit Everest without supplemental oxygen in real time, broadcasting 15-second live video clips on Snapchat. The result was a less polished, but perhaps more truthful, perspective on climbing the world's tallest mountain, and a social media first. Richards would succeed in summiting, but Ballinger would become so disoriented that he could no longer perform the simple act of opening a carabiner, and turned back less than 800 feet from the top. Ballinger had summited Everest six times prior, but always with supplemental oxygen (only about 200 people have summited without it). He'll make another attempt sans oxygen this season, again accompanied by Richards. Like last year, the two will climb from the North side in Tibet, which is far less crowded, but considered more dangerous due to harsher weather, camps at higher elevations, more difficult terrain, and no access to helicopter rescue at any point on the route.