[luckyno13]

There are also obvious barriers. We still have an issue with radiation during lengthy space travels. Plus the type of ships you would want to use in long term or large scale trips would need to be constructed IN space (or at least orbit). Otherwise the craft would be too heavy and too energy intensive to be worth while or even feasible.

We need an orbiting dry dock :)

On a side note,I think one of the simplest (but skillful and dangerous) jobs here on Earth that I would want in the age of space construction would be space welder.