Is it not true that most scientists believe that it is impossible to travel faster than the speed of light, and as you approch light speed, time slows down for you relitive to everything about you? If you stick to that scietific rule, you wont have much of a show!
I suppose you could have a show done like Kim Stanley Robinson's 'Mars' books. Set in the near future about the terraforming and colonisation of our solar system, it would be mostly scientificly accurate, and you would still have a quality science fiction drama.
BRG