Space.com

What's Hot This Week NASA Sets Sights on Mars After Unmanned Moon Shot by Denise Chow, SPACE.com Staff Writer NASA successfully launched a set of twin spacecraft into orbit today to study the moon's gravity, but the new mission isn't the first - or the last - robotic planetary expedition for the space agency year. NASA Launches Twin Spacecraft to Probe Inside the Moon by Denise Chow, SPACE.com Staff Writer Two identical space probes are on their way to the moon, after launching today on NASA's newest lunar science mission aimed at unlocking mysteries of the moon that are hidden beneath its surface. Sponsored by: China's Space Dreams Ride on Robotic Docking Test Best Space Photos of the Week - Sept. 10, 2011 European Observatory to Make 'Major' Alien Planet Announcement Scientists to Congress: Keep NASA's Missions to Other Planets Flowing Vote Now! Top Space Stories of the Week - Sept. 11, 2011