Scientists are learning there may be a reason why the human race will always remain on Earth and not colonize other planets. Because evolution has tailored our bodies to respond to specific conditions, our immune systems are not set up to work in space.
Tokyo -
Frozen 'space sperm' has passed a fertility test. Japanese scientists have produced healthy mice pups, born using freeze-dried sperm that was stored in the microgravity environment of space.
One limitation with a deep space mission, such as to Mars, is the effect of microgravity on astronauts. To find ways to build-up resilience and maintain bone strength, scientists have, surprisingly, been studying fish.