Boeing and Lockheed Martin would always use the term rocket science to make rockets seem more esoteric than they were and to demotivate new entrants like SpaceX.
These are the two code names used for the long rumored high speed black triangle stealth surveillance craft made by Lockheed Martin and allegedly tested out of Groom Lake.
Finally, there are British Ministry of Defense documents from the late 90s that discuss black triangular high-speed recon aircrafts made by Lockheed Martin that utilize exotic propulsion.