disnut8 said:
My understanding is if you go in the stand by lines, you will be split up. If you use FastPass you all go into one line and then are separated at the end of that line. Someone correct me if that's not accurate.
Everyone with FPs goes into the same FP return queue. But, standby people all get in one line, also.
When you enter the standby line, a CM asks you green or orange. You are handed the appropriate card, and everyone goes through the same queue. Everyone stays together until a certain point very near the simulators themselves.
At that point, you hand your card to the appropriate CM, green or orange. You split off to either mission green or mission orange. From that point, there's no way to make sure you get done at the same time as the other people in the party, because each side is run independently. There may be more people in the queue for one than the other, so people getting in the more crowded side will finish the ride after the people who rode the less crowded side. There can also be delays caused by slow exiting, or by someone not following directions, or by cleanup of a "protein spill" (this one is unlikely to happen on mission green).
I never did it with FP, only standby. We were at Epcot for the rope drop and went immediately to Mission:Space, and we, and others, were the first ones to ride that day.