Troy Rising

Heinlein is always great. Check out B. V. Larson's Swarm and Undying Mercenaries series, Dennis E. Taylor Bobiverse series, and Craig Alanson's Expeditionary Force. Also what I mentioned to OP, what I'm doing my annual re-listen of https://www.goodreads.com/series/51166-troy-rising They're not Heinlein by any means but they're fairly good hard science fiction. The audiobook versions all have fantastic narrators too if one has a commute.

Right now I'm doing my annual re-listen to John Ringo's "maple syrup trilogy" (next I'll do my annual re-listen of The Martian, narrated by R. C. Bray not Huwill Huwheaton) https://www.goodreads.com/series/51166-troy-rising It's a really fun series, basically an alien race appears in the system and installs a gate to open up trade with the system. It has some really neat ideas in it and some good challenges they work through from fuel to interstellar war, with the primary character being your run of the mill guy with tech industry experience working in a rural community fighting his way to being fantastically wealthy and arguably the primary defender of human space. Book 1: Live Free or Die: >First Contact Was Friendly >When aliens trundled a gate to other worlds into the solar system, the world reacted with awe, hope and fear. But the first aliens to come through, the Glatun, were peaceful traders and the world breathed a sigh of relief. >Who Controls the Orbitals, Controls the World They're a good read, but the narrator makes them quite a good listen. I've actually bought other author's entire series purely because Mark Boyett has narrated them.…