Before going on with this review, I have to point out that my scoring system here isn't intended as an attempt at an objective measure of literary quality. It simply denotes how much I enjoyed reading a particular book.
And thus, Proxima is without a doubt the most ﬂawed work to date that I've had to give a full 5 stars. Stephen Baxter is sometimes described as "Arthur C. Clarke's natural successor" (including on the back cover blurb on this book), and I completely agree: His writing largely has the same strengths and weaknesses as Clarke's did.
I loved Proxima. I was almost unable to put it down after I started it, and read its 450 pages over the course of three workdays. Its primary story thread tells the story of Yuri Eden, a cryonically suspended remnant of the "Heroic Generation" — an era of extremely energy-intensive prestige projects that essentially ruined the Earth (of course, leaving coming generations with their mess). His parents had him put in stasis in the hopes that he'd eventually be unfrozen in a better world — but, unfortunately, he wakes up in a world in which he is despised as a link to the horrors of the past. Essentially, people treat him in much the same way as the cryonically suspended offspring of Nazi party officials would probably be treated if they woke up in early 1950s Warsaw. He's eventually loaded onto an early starship along with a band of petty criminals, unemployed people and other social undesirables, and sent on a one-way trip to colonize the third planet of the red dwarf Proxima Centauri. The story of the colonization effort is one of conflict, murder, grim survival and discovery, and is done extremely well. I loved the bizarre alien ecosystem of Per Ardua (AKA Proxima C), and I also much enjoyed Yuri's story.
I particularly enjoyed the psychology of this story thread. To the UN astronauts depositing the unwilling settlers in an alien star system, this is a glorious tale of interstellar colonization. To the settlers themselves, they're being marooned by smug assholes on some bullshit planet in the middle of nowhere. This, once again, is done extremely well.
The second story thread is concerned with our solar system, and how the discovery of alien artifacts on Mercury (some of which are used to construct the starship carrying Yuri to Proxima) leads to a heating of the cold war-type standoff between the Chinese Empire and the United Nations (neither of which is unilaterally cast as hero or villain). As would be expected in such a situation, there's lots of political intrigue and backstabbing, involving both government and corporate agents — as well as intervention from AIs constructed during the Heroic Generation era. This thread I also enjoyed — particularly the aspects dealing with the alien artifact discovery.
All in all, extremely well-done hard science ﬁction.
But, as said, it also has ﬂaws — all of which are minor enough that I'm willing to forgive it, because the setting and the story are so damn good. Much, in fact, like how I feel about most of Arthur C. Clarke's works. Many of the characters are dull and somewhat interchangeable — the protagonist is essentially Philip J. Fry, played straight. There's a third story thread (involving an AI-driven starship) which completely ﬁzzles and has no real resolution. The artificially intelligent Colonization Unit that assists the settlers with various colonization tasks is essentially a walking (or, well, rolling) exposition device, incessantly dumping scientific exposition on its human charges. It's obvious that Baxter wanted to tell us these science details (and they're all, as is typical for him, extremely well thought-out), and the ColU just happened to be the best way to do it. The ending is an utterly bizarre cliffhanger (there's a sequel coming up), and unfortunately doesn't disprove my "Stephen Baxter can't write good novel endings" hypothesis.
For all its ﬂaws, highly recommended. One of the year's science ﬁction highlights for me.