If you liked The Martian, you'll probably love Weir's "Project Hail Mary" It's about a last-ditch effort by a lone scientist and astronaut to save Earth from a cataclysm. There's much, much more to it, but I really don't want to spoil it. I will say that it very much builds on core principles of The Martian, and is a fantastic read. Reminds me a bit of Michael Bear's "Eon" books and the Niven/Pournelle Motie series by way of The Martian.