i'm
very claustophobic and wondered how i would do on this ride so was nervous about trying it ( it wouldn't be the first time i've freaked in public and figured it wouldn't be the last and i really wanted to go) and came up with a game plan to ward off a crazy attack mid flight( hehe)
the result was i loved it !
my hints are :
do sit in the middle of the capsule, not the first or last in line in other words
don't watch them shut the doors( does me in every time)
do read the instructions or shut your eyes till the screen comes on.( it's ok as the ride hasn't really started so you won't get sick) once it's on it looks like it's outside so it feels fine plus there is fresh air.it's a little disconcerting when the screen comes toward you after you sit down but prepare yourself and keep telling yourself you have plenty of room and air cause you do! make yourself breath slowly and it will help calm your nerves.
don't look around the capsule and you won't feel so closed in. just watch your own screen. follow all the other instructions too so you don't get sick
if i can do it
anyone can as i am really claustrophobic( just ask the MRI tech who had to pull me in and out 6 or 7 times and my kids/husband who have witnessed many " crazed eyed/ screaming at the top of my lungs due to tight/dark space incidences" with me, can't even read A BOOk about a cave much less watch a movie( universal back to the future made me have one of the crazed attacks when you go into the cave) or go in one

however , with MS it's a fun ride and really was not as tight inside as i thought it would be. just be prepared and make yourself stay calm. i figured it's kind of like labor, if you know what's coming it's easier to take it.
my rule of thumb would be
if you can do the tom sawyer caves you can do this as i can't do the caves. if you can do star tours ( when they shut you in) it is a similar sensation when they shut the door( just don't look)..now if i could just master an airplane ( long metal tube,close together seats, piped in air
and
they shut the door)