Final Fantasy VII Walkthrough
2.13: Cid's Dream Come True
Take Cid on your team (if you don't, he will force himself in later on, so you might as well put him on the team in the first place to save time later) and fly off to Rocket Town. On the way to the launchpad, some guards will try to stop you, but the real opposition will come from one of the Turks, no less than Rude himself.
Turks: Rude (2/Rocket Town)
Immune to Status
Sleep, Return, Confusion, Silence, Transform, Berserk, Stone, Slowly Stone, Manipulate, Death
After a beautiful cutscene of the takeoff, you'll be back into your mission, which is to take the Huge Materia stored inside the rocket's head. Before that, you will have to decypher a four-digit keycode, with only Cid's confused hints as to which buttons to press. The correct combination is OK, Switch, Cancel, Cancel (for Playstation users, regardless of your buttons' configuration, the code will always be Circle, Square, Cross, Cross). Also, be aware that Cid will make a snide comment about your knowledge of the code if you enter it on your first try.
Whether you take back the Huge Materia or not, the outcome will be the same: after a cutscene the party ends up in the airship. A little brainstorming will occur, after which the decision will be made to go back to Cosmo Canyon and visit Bugenhagen.