Imagine we have found a planet that is as far as we can tell Earth like, it is relatively close to us ,say 50 light years away. Imagine we have materials 50% stronger than any we have now Imagine we have a propulsion system 50% more powerful/efficient than any we have now If we sent humans to colonize this planet. How many would you send. What would your space ship consist of. Would you go on it, knowing there is a possibility the planet may in some way be hostile to human life. Of course it will be your offspring you would have to risk.