No, really... spiders in space:
An intrepid spider may have survived the long months at the International Space Station, with scientists eager to know for sure once it returns to Earth aboard the space shuttle Discovery.
The arachnid, one of two orb weaving spiders sent to the station last November, is due to land with Discovery's astronaut crew in Florida on Saturday afternoon. The spiders, and some butterfly larvae, are part of an educational experiment with students on Earth to compare their development in zero gravity with their counterparts on Earth.
I distinctly recall, although I can't remember where, other experiments involving putting spiders in orbit. Apparently the main roadblock to their survival is dehydration, since weightlessness apparently tricks their bodies into not consuming enough moisture.