Water bears survive open space

The creature seen here is capable of surviving the harsh conditions of space. While it looks like an extraterrestrial, it's actually a tardigrade, a tiny eight-legged invertebrae also known as a water bear. Microbiologists from the Institute of Aerospace Medicine sent tardigrades into orbit last September and exposed them to the cosmic radiation and deep vacuum of space. They returned alive. From Wired:
 Photos Uncategorized 2008 09 08 Tardigrade3 The tardigrades had already been coaxed into an anhydrobiotic state, during which their metabolisms slow by a factor of 10,000. This allows them to survive vacuums, starvation, dessication and temperatures above 300 degrees Fahrenheit and below minus 240 degrees Fahrenheit.

Once in orbit, the tardigrade box popped open. Some were exposed to low-level cosmic radiation, and others to both cosmic and unfiltered solar radiation. All were exposed to the frigid vacuum of space...

Just how the invertebrate astronauts protected themselves "remains a mystery," wrote the researchers.
Invertebrate Astronauts Make Space History (Wired.com)