On the topic of the Space Mountain cannon, I was lucky enough to work back then on the original version as an operator and I do remember quite a lot from that time, including talking to the project manager and maintenance people who had been around since its grand opening.
The "Sun" as it was called internally never worked correctly from day one. It is the gear system that was coordinated with the opening of the cannon door and it barely worked through the photo shoots and previews in 1995 before stopping completely shortly after.
The recoil was also problematic and in close to a year there, I saw it work a few days at most. Annually, they'd get the budget "to fix it", they would make it work for a few days before it broke again. When they did the Mission 2 transformation, they did more extensive work and it worked nicely for a while, which was refreshing to see.
The "loading door" was turned off on purpose in winter, as the cold air would mess around with the flywheels and electric motor at the bottom of the cannon. Where are the flywheels? Between the exit of the station and the waiting line, there is a large cement pad and it is right under there. As soon as the weather warmed up, the door was reactivated and the sequence went like this:
- the train leaves the station and circles the copper tube to the drop.
- the train is dropped into the bottom of the cannon and sharply stopped.
- the loading door opens, as the pusher cart attaches itself to the fourth car.
- the pusher cart brings the train to the launch position, which was seen by people around due to the open door.
- the train stops at the edge of the cannon and the loading door closed.
- the music is full of anticipation as there was no countdown.
- once it was time (launch timer set by the operator/Ride control system gives the OK), the train was launched up in the hill and fell down the mountain.
The water vapor ("smoke") released as the train was launched was continually spewing mist in between cycles too and there were strobes on the roof, angled to look like the train was away in the sky at night. The green neons flashed too, but in 2001, the original ones broke and the replacement stopped flashing sadly.
Once they went to Mission 2, the top launch position was removed and the ability to run 5 trains lost forever. The reason for that is that the bottom of the cannon was the buffer to get the timing right to have a train dispatched every 36 seconds. With 4 trains, the launch timer is set to 45 seconds and you don't need the bottom block zone in the cannon. The capacity record during my time was 2390 riders in an hour, which meant the cast members sent 100 trains in a single hour and only had 10 empty seats during that time.
The loading door was also timed differently: the door was open as the train was dispatched and the train dropped into the cannon. Once it stopped, the loading door closed prior to launch. A countdown and lights were added to the bottom of the cannon.
Inside the ride, one set was removed: the moon sweeper. The track went through it as it exited the Sidewinder (first inversion) before twisting around into the block brake. It was mostly for people in the waiting line as on ride, you'd barely see the lights at the tip of the arms. When they went to Mission 2, they blocked all the windows in the waiting line and you lost the amazing sight of watching the fluorescent trains spinning all around you. There was another great diorama of a galaxy at the end of the stellar walkway (the name of the indoor waiting line) which you can't see now, but I don't know if it was removed like the Moon Sweeper.
One long gone effect that was replaced by red LED lights now is the Spark Trench. The spark trench is situated right before the "Tongue Loop" (third inversion) and originally, two sparklers were installed there and those shot bright sparks as the train "crashed through a meteorite" on the way to the inversion. Alas, the chosen sparklers were not meant for an intensive use and those barely lasted a month after opening before being shutdown. Similar sparklers were also present when Test Track and Countdown to Extinction opened and those didn't last too.