The Expanse Series by James S. A. Corey. Currently on Cibola Burn.
Pretty good sci-fi. Got involved after seeing the second season and then the first season on SyFy. Very good grasp of physics, even in the inventions and liberties taken.
But got interrupted by the new Mitch Rapp book, Enemy of the State.
Kyle Mills seemed to reach his stride in the last book, so I've been looking forward to this more than the American Assassin movie. That could be good- but I've already seen changes, so bracing myself for it not to be.