Star Trek DS9 began while Star Trek: The Next Generation was still on the air, and there were several crossover episodes... More
Star Trek DS9 began while Star Trek: The Next Generation was still on the air, and there were several crossover episodes between the two shows. Unlike its predecessor, DS9 often broke the rules laid down by Gene Roddenberry, such as the prohibition against interpersonal conflicts between the main characters. In contrast with the other Star Trek programs DS9 took place on a space station instead of a starship. This made continuing story arcs and the appearance of recurring characters much more feasible. The series also depended on darker themes, less physical exploration of space, and an emphasis (in later seasons) on many aspects of war.