Continuity mistake: There are two crews boarding their spacecraft, called "Freedom" and "Independence." They are mounting a ramp and when on top, there is a crew member who directs the two different crews toward their ship: "Independence on the left, Freedom on the right." We even see the ships (in their initial launch phases) right next to each other - you can see one right next to the other as they launch. Then, once they're airborne, we see a long shot of the two bright engines, miles apart.
Picture added by Ronnie Bischof