The Ragged Astronauts was nominated for a Hugo a while ago, but I don't believe it won. I'm not entirely sure why it was nominated. I enjoyed it, but I don't feel that it achieves the heights that would warrant a nomination.
It's solid, entertaining science fiction, with a bit of a hidden-until-the-end environmentalist message.
It is also, oddly, the second book I've read recently that revolves around twin planets - Anarres and Urras in The Dispossessed, Land and Overland in this one. Land and Overland are even closer, close enough to share an atmosphere, so that, as the title might suggest, it is possible to attempt transit between the two planets with little more than a hot air balloon aided by jets.
Land has no metal, so their technology is very limited, and mostly depending on chemical interactions between two kinds of crystals found in the brakka tree. They live in a monarchy, with an inherited vocational caste system. How this was set up, and truly, what it means, is not explained. Women are not mentioned so much, but do appear to be wives. Multiple marriage is possible, but the implications are not pursued.
And therein lie my problems with the book - there are interesting ideas that are lightly touched upon, and then never pursued or developed. This would be fine if there were other
things that were developed in more detail, but there really aren't.
This is the story of an Exodus, of the sudden and devastating attack by gas creatures, of the philosophers who make the trip possible, the one philosopher/military character's struggles, and the sociopathy of a prince. It is just remarkably sparse. It is not a novel of ideas. There is not enough done to develop the characters to make it a novel of character. I guess it's a novel of plot, and what's there is entertaining enough, it's just not anything more.