The height requirement sign at Mission: SPACEIf you’re traveling with the kids or grandchildren, or there are other little ones in your party, measure them before you leave home, then learn which rides they won’t be tall enough for. Kids who are borderline will be measured as many as three times before getting onto a ride. You won’t talk a Cast Member into it, and the child throwing a fit will not make a difference. (I’ve seen that happen countless times.) The rules are in place for the safety of the children, and there are plenty of things to do that do not have a height requirement.