I don't have much to go on, I only saw one or two episodes and I was very young in the mid-80s, early 90s. I believe the premise of the show is as follows:
The crew of a spaceship arrives back at Earth. Except for one of them, when the crew wake up from hyper sleep they are all suddenly evil, and want to take over earth,or take advantage of something on earth. I think whatever happen to them also gave them super human powers or weapons. I think crew of the spaceship were all scientists as well.
I know its not much to go on but does this sound vaguely familiar to anyway?