Have you ever dreamed of going into space?

It is certainly something that many people have dreamed about but few have managed to achieve.

However, space travel does appear to have some negative side effects, one of which could be its effect on fertility.

Scientists have been gathering evidence from past and current research, much of which appears to indicate that zero gravity conditions does affect individual fertility  in animals.

Researchers are unable to tell if these results would be the same for humans, but it could still be a cause for concern for space scientists and astronauts.

One of the earliest pieces of research in 1979 found that male and female rats sent into space refused to mate. A similar study which put male rats into a zero gravity situation failed to produce sperm.

In order to determine the seriousness of this, and to determine potential causes, NASA scientists recently transported mice to the International Space Station.

So far, the research does not appear promising.

There is a suggestion that the cause of infertility may be space radiation (rather than zero gravity conditions) which is damaging male sperm production as well as female ovaries, but this is not absolutely clear.

It could be a combination of both.

Speaking with reporters, Dr Joseph Tash, from the University of Kansas, said that while it is too early to extrapolate animal research onto humans, the same results are highly likely.

He added that this area of research is something that should be developed, especially since NASA and other agencies around the globe do have plans to travel further into space in the future.

It may be necessary at some point for humans to be tested to determine the effect of space travel on fertility.