A European Space Agency experiment shows that tiny eight-legged invertebrates known as "water bears" are the first known animal to survive the vacuum and radiation of space.
The hardy critters, also called tardigrades, are between 0.1 to 1.5 millimeters long and thrive in moist conditions. They can commonly be found munching on wet lichens and moss, but are quite capable of living in harsher conditions such as dunes, mountaintops and ocean depths. Should their environment become too dry, water bears can stop metabolic function to enter a state of cyptobiosis until conditions return to being more hospitable.
More: http://www.theregister.co.uk/2008/09/10/water_bears_in_spaaaaaace/
:D Yay for tardigrades in space! :D