A year ago, on December 21, 2015, SpaceX pulled off its first Falcon 9 rocket landing at Cape Canaveral, Florida. Although there were many pictures and videos documenting the historic event, company CEO Elon Musk’s reactions to the event were unknown – until now.

National Geographic has shared incredible footage that looks at Musk and the roller-coaster he went through while trying to decipher what was going on, starting with the launch all the way to the return of the first stage. From a burst of anxiety to pure ecstasy, the SpaceX CEO, who is generally restrained, displayed a variety of emotions ranging from despair to absolute joy.

At one point, he panicked as he observed the landing. The moment passed, though and he ran back inside excitedly, shouting, “It’s standing up!”