[hcknwscommenter]

Not saying this is the case for spacex, but in my field (totally not space or engineering or software (but very much "tech" (physics/chemistry)) related), these types of interview are for weeding out the non-standard folks (of which there are many, including me but many of us (including me) have become good at hiding it). A person with high E would presumably (but not always because it is indeed a difficult task, casualties are regrettable but expected) "grok" the task and begin feeding the right keywords to the recruiter. Once you realize the game, it becomes fairly easy. Just read the job description and sprinkle the keywords provided therein.