Here's more on the story from USA Today:
Kate Upton defied gravity in one of her photo shoots for Sports Illustrated’s 2014 Swimsuit Issue. And it was insanely awesome. The SI Swim crew boarded a Boeing 727 run by the Zero G Experience, in which they planned to shoot in zero gravity. Weightlessness is attained through a series of aerobatic maneuvers known as parabolas, where the pilot pulls the aircraft up at 45 degrees to an altitude of 34,000 feet, and then pushes the plane into a descent to create zero gravity for 20-30 seconds. Upton, wearing a gold bikini, tumbled all over the place, as did the photographers. But they got great photos and video.