acutally pets dont need to be in space. Not until we have actually established ourselves out there - which likely won't happen this century.
Sending animals into space were strictly experiments and none of the people at
NASA nor in the CCCR had any expectations or intentions of bringing them back to Earth alive. They were sent up to see what the effects of weightlessness and the lack of an atmosphere was on mammals - which is what we are essentially - mammals. They wanted to perfect their rockets and space capsules before sending man out there. It would have been quite disastrous for the space programs to have the loss of human life on the inaugural journey to space. But because we were successful from the get-go the space programs are able to continue despite fatalities on other flights (Challenger, Apollo, Columbia).
But the current spaceships (Discovery, Endeavor) are going to be decommissioned in 2010 and we will not have a replacement ship until 2015 - for 5 years we are going to be dependent solely on Russia's half-assed space 'program' to get our guys up and down.
For years the general public has been wondering - when are we going to return to the moon? We haven't touched the moon for decades - but what they dont realize is this: it's WAY expensive! To be practical several countries not just the USA would have to help fund such a journey and USA couldnt claim the moon to itself - although the US flag is still up there. I think several countries could benefit from experiments conducted on the moon as well as recent data recorded from the surface of the moon.
For regular trips to the moon to be possible it would be a joint project from several countries and it would have to be scheduled years apart -like every 5-10 years.