RocketSTEM Issue #3 - October 2013 | Page 8

Image: NASA EDGE Image: NASA Ames/Dana Barry The Minotaur V rocket (left) that will carry NASA’s LADEE awaits launch from Pad 0B at NASA’s Wallops Flight Facility at Wallops Island, Va. An artist’s concept (right) of the LADEE spacecraft orbiting the moon and preparing to fire its maneuvering thrusters to maintain a safe orbital altitude. By Emory Stagmer Did you know the moon has an atmosphere? I wouldn’t be surprised if you didn’t. Until just a few years ago nobody did. It’s not much. You can’t breathe it. We think it’s mostly dust. But we don’t know exactly what’s in it or how it works. How does an atmosphere operate when the days are 28 earth days long? That’s 14*24=336 hours of daylight followed by 336 hours of night time. How does an atmosphere work when the gravity is 1/6 that of Earth? How does an atmosphere work when it’s bombarded by the sun’s solar wind at a million miles an hour? How does an atmosphere work when the sunlit portion of the moon is +120 degrees C (hot enough to boil water) and the dark areas are -170 degrees C (cold enough to freeze air)? Those are the kinds of questions NASA is trying to answer with the LADEE satellite, the Lunar Atmosphere and Dust Environment Explorer. Technically the atmosphere on the moon is called a ‘surface 06 06 boundary exosphere’. “Surface Boundary” means that it goes all the way down to the surface. But it’s a trillion times thinner than the air we breathe here on Earth. It’s so thin