Space Mountain, the roller coaster that launched Walt Disney World into a new era, turns 50 years old this month. The ride, a key part of Magic Kingdom’s first major expansion, opened to the public on Jan.

Fifty years ago this week, Space Mountain opened in Magic Kingdom at Walt Disney World. The original Space Mountain, which opened at Walt Disney World in 1975, was the first fully-enclosed, dark roller coaster and the first to be controlled by a computer.

Opened on Jan. 15, 1975, Space Mountain was launched in the Magic Kingdom’s Tomorrowland with a network musical variety special that you can still see on YouTube hosted by Lucie Arnaz and Broadway legend Tommy Tune. (Because this was the ’70s and we loved musical variety shows and groovy fashions).

When the ride opened on Jan. 15, 1975, an Apollo moonwalker was its first passenger, NASA's insignia was on display and Space Mountain was dedicated to opening the new frontier.

Space Mountain is one of the most recognizable theme park attractions around the world, but here’s what you may not know about the beloved ride.

As the demolition of the old Space Mountain and construction of the new one continue, work is now visible from inside Tokyo Disneyland. Space Mountain Demolition and Construction Tokyo Disneyland’s original Space Mountain — which opened with the park in 1983 — closed permanently in July of last year.

Space Mountain, at Walt Disney World! Celebrate the magic of milestones at Walt Disney World this year and reminisce about your own Disney childhood milestones.