> A lot of the novel strained my ability to suspend disbelief, but the overall scope and ambition is so awesome

While the 2nd half of the book is definitely still sci-fi territory, the first part is slowly getting into the plausible tech realm, 12 years after the book was written. We now have a much stronger space industry, and probably could match or exceed the payload to orbit in 2 years from the book (if everyone would work towards the same goal, which is still a bit of fantasy but hey...)