The Calculating Stars (Book 1 of the Lady Astronaut duology) by Mary Robinette Kowal

“The first half of Kowal’s two-book tale—The Fated Sky will follow—begins in 1952 when a meteorite strikes Earth, causing a global cataclysm. The eastern coast of the U.S. crumbles, and the rest of the world faces a climate shift…Although Kowal’s latest is a definite deviation from her popular Glamour Histories series, she once again strikes a fine balance of integrating historical accuracy—including mid-twentieth-century sexism, racism, and technology—with speculative storytelling. Readers will root for Elma as she breaks barriers and calculates lifesaving equations, all while dealing with sometimes-crippling anxiety. Recommend to fans of realistic sf.” — Booklist