Have you considered or looked at distance learning programs for Master's degrees? Georgia Tech has had a program for several years, as does University of Missouri-Rolla, Kansas State University, Idaho State University and many others. You'll need to do a lot of research because the programs differ greatly in their offering. For example, the Georgia Tech program offers very little in the way of thermal sciences, which was my concentration so that program was out for me. You'll also want to look at the other programs that are offered because you may want to take a few classes from outside ME to broaden your experience. If your options are limited, you might not get all you want out of your program.
I recently completed my MS through distance learning while working full time and raising a family. The flexibility of the programs are great when you are facing other commitments. Most of my classes were videotaped on campus and delivered to me on video or DVD to watch. I took the same exams and completed the same homework as on-campus students, talked with the professors, etc. The only difference was I didn't have to drive to campus or attend a regularly scheduled lecture. Having the lectures recorded also meant I could rewatch anything I didn't understand. It was truly a worthwhile learning experience. You do really need to consider the future as well because it will probably take you 3-4 years to complete the program part time. When I started the program, I had no children. When I finished, I had 3 boys. That made the last few semesters difficult because I wanted to spend more time playing and less time studying so you really need to get your wife on board with you to encourage and motivate. Good luck with your decision.