In The Hitchhikers' Guide to the Galaxy, Douglas Adams wrote, "Space is big--really big--you just won't believe how vastly, hugely mind-bogglingly big it is. You may think it's a long way down the road to the chemist, but that's just peanuts to space."
Space's roominess is good news for us rapidly multiplying humans, because it seems logical that we should one day want to expand into our solar system--and possibly further. But because of our frail and squishy bodies we need some heavyweight protection to leave the cozy home comforts of our bijou atmosphere, and great ingenuity to even have a look around. This list celebrates the best spacecraft--those that have taken us to new places or brought us information about what's out there. Take the intergalactic tour.