The hollow asteroid concept seems to me to be the most viable solution to space travel. Without it we are reduced to living for generations inside a metal machine which is designed to get the journey over with as fast as possible.
An asteroid of considerable size, like the one in my book ‘Biograph’, is called Culminatorics. It has an innersphere that is 45 miles across and has the same area as the county of Yorkshire in the UK. A living space of that size makes space travel very similar to what we are doing right now on our home planet. It provides mountains, deserts forests, lakes and rivers. With living accommodation between the outer surface and the inner, the innersphere is designed as a playground, habit and zoo for the other plants and animals the diaspora of humanity would take with them (they invite a herd of elephants that roam free across the internal plain). Fifty million people can be accommodated. The journey could take two hundred generations. Coming back is not really an option.
http://www.amazon.co.uk/Biograph-John-White-ebook/dp/B006C7HXK0
