Space shuttle commander Eileen Collins, who is scheduled to go up in a return-to-flight mission this July, can handle the pressure of riding a spacecraft loaded with tons of explosive rocket fuel into space, and returning to a fiery reentry.

However, Collins cannot handle an amusement park thrill ride, such as a roller coaster or water slide.

Collins was last on a roller coaster 20 years ago, when she visited Space Mountain at Walt Disney World.  Since then, anytime she’s tried to go on one, she could not bring herself to ride that ride.

Flying in space, as she says, is different.  She feels that there is a certain amount of control in what she does, and is rewarding in the end. 

For more on Collins and Discovery’s mission, visit CNN.