The main entry to the building is via the large red/orange planet. From here you can collect a FASTPASS ticket, and then exit to the right of the building past the smaller red/orange planet, or you can enter the main pavilion/ride building. The primary exit is to the far left of the building. There is also a "chicken exit" for those guests that wish to experience the pavilion, but do not wish to embark on the main event of the attraction (similar to the Tower of Terror chicken elevator concept).
Diagrams are at http://missionspace.wdwmagic.com
Enjoy!
Diagrams are at http://missionspace.wdwmagic.com
Enjoy!