Our Space Mountain (pre-refurb) is ROUGH. Really sharp turns, big drops. It slams you one way, then another way. Of all the Coaster's I've been on, our Space Mountain is by far the scariest. See other coasters may look scarier, but their designs are far less scary, because they have smooth, precise, drops turns & inversions, designed for precision.
As for Mission Space, you have to remember they're not "Sealing you in". The only reason the thing is lowering is so you can press buttons-which is a ton of fun. MS is just like centrifuge training, it only feels funky the first time. Go on it more and it becomes a cake walk.
(And Air Time is a hoot- It's nothing. You're the all edumacated one, you should know that physics will NEVER let you fly into the air and out of the car. Same for Inversions. Math is always going to make sure you return to the station...:lol: )