You're a fundamentally hard sf writer. One does what one knows how to do. I had a fairly successful career in science and engineering. I had some military experience in early life, but mostly I get what I know from books, and from having worked as a military operations analyst in the 60's. Some colleagues of yours who specialized in hard sf, as Poul Anderson or Larry Niven, started to write fantasy.
Fantasy is fun, and now there's a big market.
For full time writers, market potential is important. We do have to make a living. We also want to enjoy what we do. We've covered this a lot in other places. Mostly we make sure we know where the book is going.