The Calculating Stars

On a cold morning in March 1952 a meteorite hits the water off the coast of Maryland and destroys Washington and most of the eastern seaboard. Elma York, a mathematician and wartime ferry pilot, survives because she and her husband are in the Poconos, and she is the one who works out that the impact has put enough water vapour into the atmosphere to make Earth uninhabitable within decades.

So the space programme stops being a race and becomes an evacuation. An international coalition begins building toward a colony, and Elma, who flew for the Women Airforce Service Pilots and can do orbital mechanics in her head, computes trajectories for men who will not consider letting a woman fly.

The campaign she ends up leading, for women astronauts, runs into every obstacle of 1950s America at once, and Kowal is careful to show Elma learning that the door she is pushing on is shut much harder for the Black women pilots beside her, several of whom are better qualified.

The other thread is private. Elma's competence is real and her anxiety is disabling, and the book takes both seriously without curing either.

Her husband Nathaniel is the lead engineer on the programme, and the two of them are a genuinely functional couple who talk about work in bed, which is rarer in fiction than any amount of orbital mechanics.

The alternate history is worked out properly, from the politics of a government reconstituted in Kansas City to the way a public relations campaign becomes the only lever available. The mathematics is real and Kowal shows enough of it to be convincing without stalling the book.

Around four hundred pages, briskly told, and considerably angrier than its friendly surface suggests. Expect an unflinching account of segregation inside the programme and of what it costs Elma to be the acceptable face of it.

Best for readers who liked Hidden Figures and want the version where the rockets are an evacuation.