Initial plans for Space Mountain by Walt Disney and his Imagineers in the early 1960s conceived of a spaceport in Disneyland’s Tomorrowland with four separate roller coaster tracks weaving inside and outside a towering futuristic peak with a much less majestic name.

“Walt and the team had an idea to do a spaceport within Tomorrowland,” Disney Imagineer Owen Yoshino said on the Disney+ series “Behind the Attraction,” adding that the featured anchor attraction would be Space Voyage.

The successful debut of Matterhorn Bobsleds in 1959 at Disneyland prompted Disney to ask his creative team to dream up a space-themed roller coaster for Tomorrowland that would be more technologically advanced and twice as big.

Disney Legend John Hench known as Walt’s “expert at everything” created the first Space Voyage conceptual sketches. The original concept for what would become Space Mountain had four tracks weaving in and out of each other and through a large mountain similar to the Matterhorn track layout.

The big technological advance a computer-controlled brake-blocking system to keep coaster trains from colliding was way ahead of its time. The project was ultimately put on hold, but it was soon resurrected.

A Disneyland map from 1968 showed an unnamed “future attraction” in Tomorrowland that looked a lot like Space Mountain with coaster tracks encircling the futuristic peak.

But by that time, another project was occupying the attention of Imagineering the new Magic Kingdom theme park that would soon open in Florida in 1971.

Competition in the burgeoning amusement park industry pushed the Imagineering team to shift plans for Space Mountain from Disneyland to the Magic Kingdom where the space-themed indoor roller coaster debuted in 1975.

The Magic Kingdom’s Space Mountain ride ended up with two tracks instead of four, both of them indoors. The Florida version of the ride was essentially Disneyland’s Matterhorn track layout built inside a fully-enclosed mountain.

The instant success of Space Mountain at Walt Disney World prompted Imagineering to fast-track a version of the ride for Disneyland that debuted in 1977. The Anaheim mountain would be 200 feet in diameter, significantly smaller than the Florida mountain, which was 300 feet in diameter.