On this day in 1975, Space Mountain opened at the Magic Kingdom at Walt Disney World. It was the first of several similar attractions to open around the world. The original concept came during the reimagining of Disneyland’s Tomorrowland in 1967. That version would have been a four-track design, but it was never built because the technology was not quite ready. The eventual two-track design was inspired by the Matterhorn Bobsleds at Disneyland. [50 years ago in 2025]