There's nothing like the end of the world to focus the mind, so when the date for armageddon is fixed by a catastrophe in the sky, all effort is bent towards saving the human race, or some small part of it anyway. There follows a great deal of technical exposition about surviving in space, and for the most part it's a riveting story, but those technical explanations - and, to be fair, technical explanations tend to be the stuff of hard sf - do go on and on, delaying the action of the story, sometimes suspensefully, sometimes, not so much. Anyhow, it's a grand project against all odds, a titanic effort of will and intellect and expertise and character and vision and all that good stuff ramped up as only the impending extinction of the human race can achieve. It did remind me of some Niven-Pournelle books that I enjoyed back in the day, albeit reminding me that I don't have a huge amount of time for that sort of book any more.

Then, two thirds of the way through, it jumps ahead 5,000 years for a tour of the massive engineering projects that have been completed since the end of the world, not to mention the results of various genetic and social engineering projects. Epic in scale, but again, I just wanted more of the story. An argument could be made that the engineering was part of the story, but c'mon. I did enjoy it, but too much of the time I felt I was tackling it rather than reading it.

Relistened, and yes did kind of zone out for more of the tech stuff than I'm confortable admitting BUT it also used Ireland as a unit of measurement twice, and I just saw somone say that Storm Hilary, about to hit Mexico and California, is the size of Ireland, so it's not a lot but it is odd that it happened three times in one day.