Mars has been a source of fascination since H. G. Wells wrote The War of the Worlds, a sci-fi fantasy of green-eyed Martians invading and overpowering Earth. In 1971, engineers succeeded in placing a spacecraft into Mars's orbit with the idea of finding out what was on Mars: Intelligent life? Water? A place people on Earth could move if need be? Since then, a number of missions to Mars have been launched. Now is your chance to help launch the Mars...