Space Mountain in Walt Disney World celebrates 50 years of operation. Initially opening on January 15, 1975, Space Mountain, an indoor steel rollercoaster themed to space travel, has been a staple of Tomorrowland, the area of the Magic Kingdom park where the ride resides.

Walt Disney wanted to build Space Mountain at Disneyland a decade before the indoor roller coaster forever altered the skyline of the Magic Kingdom a few years after the debut of the Florida theme park. Disney’s Magic Kingdom theme park will celebrate the 50th anniversary of Space Mountain on Wednesday, Jan. 15.

A cultural touchstone, the dark ride opened to the public on Jan. 15, 1975, three years and three months after the Magic Kingdom’s debut.