I don't know...Ted Taylor was the one chosen to design the bombs. Based on his history that part would have been a lead-pipe cinch. The rest of it--well, as long as they avoided the giant-spring-looks-like-a-sperm interstellar version there was no Unobtanium in the design stuff I've seen. Now the test system NASA demanded before man-rating it? THAT would scare the shit out of anyone.