The Calculating Stars, by Mary Robinette Kowal
The story opens in the early 1950s with a meteorite crashing into and obliterating Washington DC and much of the eastern seaboard. Scientists quickly realize that Earth will become uninhabitable for humans by the end of the century, inspiring an international mission to colonize Mars. WWII pilot and mathematician Dr. Elma York pushes to become the first female astronaut.
If you're reminded of the book/movie Hidden Figures, you're not far off. The racism and sexism of the 1950s is alive and well alongside the rapid technological advances that get the astronauts off the ground. The story is a fascinating post-apocalyptic alternate history and the protagonist is empathetic as she struggles to balance her interstellar ambitions with her own flaws and reservations. My only objection, albeit a slight one, is that Elma's husband, a main character within the story, is a little too good to be true with his bottomless well of support and foot massages.
Publication date: 2018
First in a trilogy (with links here to book 2 and book 3.)
The first step to writing a terrific post-apocalyptic novel is reading what is already out there in the genre. Once you've written your own and are ready for an editor and/or proofreader, I'd be honored to read your work. Together we will make your book shine!