Screw a spaceship, we want a time machine! Time machines rule, because they crack open the mysteries of the past and future. And each time machine has its own weird personality. And if you visited another planet, you'd probably suffocate.
Mars Needs Moms is a decent movie. Maybe even a pretty good movie. But nobody seems excited about it, and that's probably because it was made using Robert Zemeckis' motion-capture process, as used in Polar Express and Christmas Carol.