When the Matterhorn Bobsleds opened in 1959, they were an instant hit with guests. DISNEYLAND management begged Walt Disney for another roller coaster style ride. Even Roy O. Disney, who had originally fought against building the Matterhorn was eager to add another hugely profitable coaster to the park. Walt Disney came up with the idea for an indoor coaster that would simulate being blasted into outer space with special effects taking place in a pitch dark environment. The project was temporarily shelved when the technology to build Walt Disney's full vision was not yet in existence. Imagineers suggested building a "Matterhorn indoors" but Mr. Disney refused to compromise his vision.
When Disney World's Magic Kingdom Theme Park needed a roller coaster, the idea that Walt had rejected was resurrected; after all, Florida's park didn't have a Matterhorn. The "Matterhorn Indoors" version of Space Mountain opened in 1974. By this time, technology had caught up with Walt's imagination and his full vision was finally realized in Anaheim on May 27, 1977.