This was one of my favourite movies when I was a kid. I came across it on VHS at my local rental store, so I never knew it was anything other than just a Disney movie.
Scott Bakula plays a single father of a boy in his early teens (Joey Cramer, from The Flight of the Navigator), who is on the scene when a truck carrying space gas is involved in an accident caused by some villains (as you do). Bakula, his son and their dog rush to the truck to see if they can help, and are exposed to the space gas - which gives father and son (and maybe dog) the ability to regenerate - no matter how severe the injury, they heal in a matter of minutes.
It turns out their new superpowers come with a rather inconvenient kryptonite: the dark. Without light, they begin to have difficulty breathing and might very well die. This gets tricky when the son stows away on a mission to thwart the badguys, and when the father finds himself often the dark (literally) during the mission.
It's a little bit Six Million Dollar Man, a little bit MacGyver, and a little bit Condorman - action adventure for 10 year olds. I loved it when I was a kid, and when I stumbled across it a few years ago, I still enjoyed it.
Plus, Scott Bakula is fairly easy on the eye.