Andy Weir does it again, managing to make science and space engineering fun and engaging. In Hail Mary the stakes are a lot higher than in The Martian, because there is more stuff to save like... the world. There are some holes in the logic of the book, but it's a fun read where basically two guys spend the entire book fixing things, researching things and trying to stay alive. In short, if you loved The Martian you will like this book.
I know these books are not really related and in no way does the author owe me anything, but I got a little disappointed with the now predictable evolution of space story: start with something close to reality, like a manned Mars mission or a Moon colony (hey! These have been realistic for 50 years! Classics!), then immediately find a gimmick that allows you to move among stars where everything is more exciting than in boring Sol system. Bigger, brighter and with more explosions. I understand that is the demand from the public, but what I personally enjoy about Weir's stories is the focus on the character's problem solving process, then using actual science to get by. I don't care about the size of the stakes. The less realistic and immediately possible the plot, the less I feel involved.
Bottom line: a fun read, similar to The Martian, but bigger.