I see the astronauts at the International Space Station are getting pets of sorts. More than pet fish, really. These little guys will help researchers determine the progress of bone and muscle loss in a microgravity (weightless) environment. That’s the one big issue that Mars mission thumpers don’t talk about a lot. Even though they insist the astronauts on long Earth-orbit missions exercise daily, nobody as yet has a handle on how to stop the human body from adapting to the sense of weightlessness one experiences off-planet.
These fish, Oryzias latipes, have already been taken into orbit on previous US shuttle missions and bred in space.
If it were me, I’d prefer a nice cat for a space station pet.