On orange, they warn you NOT to close your eyes during the ride, even if you start to feel disoriented/sick. Not watching the screen or turning your face away will cause your body to experience the ride as spinning, which will increase your likelihood of getting sick.
I rode it for the first time a couple weeks ago. Yes, it's very intense, but I'm glad I did it. It's truly a unique experience and it really does feel like you're being hurdled through space.
Honestly, I think Space Mountain is more disorienting because you can't see where you're going. On Mission Space you always have a visual guide to help interpret the way you're moving. Hopefully that makes sense.
Some other folks in our party did the less intense version and still enjoyed it. My son did both and said it was nonetheless a very different experience between the two of them.