Rüdiger Nehmzow means "Man With Big Balls Made of Steel" in German. After watching this video of him taking photos of clouds from the open door of a plane, 6km up in the sky, it can't mean anything else.
Rüdiger straps himself into a plane, opens the door at 6000m and, equipped with his camera, an oxygen mask and jacket to protect him against the sub-zero temperatures, hunts perfect photos of clouds. Looks like fun to me and the photos look even better. [Nehmzow via PetaPixel]