By 6:45 on a chilly desert evening, a deep indigo sky has squeezed what remains of the day into thin lines of pink and turquoise twilight along the horizon. Satisfied with nightfall’s progress, NASA engineer Joe Kosmo gives the word, and his crew begins to pressurize a spacesuit glistening under a floodlit canopy. Tonight’s objective: to test new helmet lights to see how effectively they might illuminate an astronaut’s path. If you’ve ever wondered how exploration equipment makes its way into space, welcome to the rolling flanks of Arizona’s famed meteor crater. For two weeks a year, this stark landscape becomes a surrogate planet – a place where a small team of scientists from the National Aeronautics and Space Administration drive a futuristic electric tractor, guide small robotic “scouts,” and test an array of other gear astronauts may need in their cosmic garages for future explorations of the moon and Mars.