http://www.npr.org/2015/05/11/...d-elevators-in-space
Astronomer Chris Impey examines the possibilities of the universe in his new book Beyond. "I like the idea that the universe — the boundless possibility of 20 billion habitable worlds — has led to things that we can barely imagine," he says. In the 1970s, NASA Ames conducted several space colony studies, commissioning renderings of the giant spacecraft which could house entire cities.

Colonization is possible, given a blank check...those who encourage exploration and colonization, even to Mars, don't seem to comprehend the costs. Who will pay for it?

I'm all for scientific advance and space travel but I would rather see that money spent on the elderly...Me

I'm an amateur astronomer, and many of my colleagues slobberingly support unbridled space exploration (especially manned missions), with no concept of not only the costs, but of the inevitable cost overruns.

The James Webb Space Telescope is just one example of the overrun largesse contractors enjoy (well over budget - originally $1.6B, now capped at $8B).

When Perkin Elmer figured the Hubble's mirror incorrectly, the taxpayers picked up the tab for the successful Space Shuttle mission to fix it.