Project Hail Mary by Andy Weir,if you enjoyed the Martian you will love this.Out in paperback.
Just read the reviews, sounds fantastic - on my list
The first act is one of the most enthralling things I’ve read in a long time. Proper hooks you in with the intrigue from the start.
Thought it got a little predictable near the end (things go wrong, main character uses knowledge of SCIENCE! to escape by the skin of his teeth, rinse/repeat)
Still an excellent read regardless!