And the whole concept is based on real hardware and real science, in other words, a decent chunk of the technology is already here, and is also proven to be possible according to the link below about a test by NASA.
http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=3
According to the article and the second link, this may not be a fantasy that will take decades to have visible results in spacecraft technology.