‘unobtainium’ - Was that really in the movie? Sounds like a Jay Ward concoction for a Rocky and Bullwinkle story line. (Remember the upsidaisium plot?)
unobtainium is a joke I first heard as an engineering undegrad in the 70s. “Here’s something we could build but first we’ll need to get some unobtainium”. It’s engineering shorthand for a project you could do if only you had a material that was light enough, strong enough, or whatever physical property that’s keeping you from doing what you want to do.