Have you considered working at any of the national labs (LLNL, LANL, ORNL, etc.)? When I worked there I knew a lot of former armed forces members who had learned interesting scientific or technical specialties. It’s just an idea, in case it piques your interest. Most of the labs would be happy to have a motivated employee who is also interested in concurrently getting a college degree. PM me if you’re interested and I can try to provide more detail.