I keep my book review ratings simple—they’re either required, recommended, recommended with qualifications, or not recommended. If you want the TL;DR, this is it:

Required: Mary Robinette Kowal’s alt-history of the space program (after a meteor strike!) is wonderful—smashingly-good plotting which somehow makes a half decade span feel urgent and fast-paced; a fantastic lead character; an interesting examination of women’s friendships; and frank treatment of both sexism and mental illness without being preachy about either. This was one of my favorite pieces of science-fiction I’ve read in a long time.