I'm not sure of the height requirement (46 inches maybe?), but my son, who is 6 1/2 and about 47 inches tall, did Mission: Space when we there in June. He loves all coasters and just about any attraction. He liked Mission: Space, but only wanted to do it once -- he said his head felt "heavy" when he got off. He said he didn't feel sick and he was fine the rest of the day.