Almarg, I doubt seriously if the solder you and I have access to is anything like that used in the military.
Tbg
I spent 20 years as an electronic tech in the USAF and there was nothing special about the solder we used. Yes I was soldering components on boards as well as connectors used in aircraft. Now maybe NASA uses something special, but I doubt it.
A good solder joint is going to last. It just has to be done properly. That's what quality control is for.