I took this photo on the moon. (Not really - just checking to see if you're paying attention!) This is geologist Dean Eppler, the "suit subject" during a National Aeronautics and Space Administration outing in the Arizona desert. Members of NASA's Desert RATS (Research and Technology Studies) team test their equipment here, where the landscape resembles that of the moon. The fun began after sunset: The "desert rats" wanted to see how well the helmet's new light array penetrated the darkness. I couldn't use flash because it would have ruined the test results. Fortunately, light from the suit itself let me get a few usable shots. But it's Dr. Eppler's smile I'll remember most. It flashed across his face frequently as he donned the heavy suit (it weighs 200 pounds). He's older than the astronauts who will wear these suits in space, but Eppler is the right size to test it. His vital signs were carefully monitored so he wouldn't overexert himself. A sophisticated built-in cooling system kept him comfortable. It was an honor to photograph these grown-up boys and their NASA toys because they so enjoy their jobs. They love what they do as much as I love taking their pictures.