This was mentioned by someone in the on basilisks station thread. It’s the first book in a spin-off series co-written by Eric Flint and David Weber (though I think most of it’s written by eric flint, you can really see his style).
Eric Flint is a fun writer to read, I think. He has less of the “sameness” Weber’s characters start to have whenever they agree with each other. He’s better at characterization then Weber I think.
And you can read it online for free from baen’s web site!
BTW, baen’s free library is really cool. Check it out.
Joe