[hattend]

I think a Mars Dog would live about as long as Leika did when the oxygen ran out. Until we terraform Mars and get a denser atmosphere, live things will need a spacesuit.

BTW: Is Leika still up there or has that spacecraft long since burned up on reentry? Anybody know?

[jboot]

I'm not sure if Laika is still up there, because the early Soviet orbits were very high. I do know that she didn't die when her oxygen ran out. She was chemically euthanized by an automated system at the end of the mission.

There was a second "space dog" (her name escapes me) who was safely returned to Earth. She lived long enough after returning to be bred and bear a litter of perfectly normal puppies.