Ok this may be a little hard-pressed to find out but let's see..

All I can remember about this sci-fi TV series was that it was about a man who was from Earth but somehow he got put on a spaceship and throughout all the series' he was trying to find a way back to Earth. And then finally right at the end of the series', he got back to Earth, and was in a boat with a woman he had met whilst in space and had just proposed to her when their ship's pilot (who was ill or something bad had happened to him..) suddenly opened fire on them and killed both of them.. and that's as much as I can remember.. any answers would be greatly appreciated, thanks.