The very, very impressive thing about the space-plane thing is they had the guts not to do it. Apparently it worked out to be no better than kerosene, so they just stopped. That's a mind blowing thing for any large research effort: to just stop doing something because it's turned out to be a bad idea. It's such an unexpected move that it spawned whole families of conspiracy theories from people who just could not believe you could set out to build a hydrogen powered space-plane, set up hydrogen production, start building, then just stop.
They designed a stealth-boat too.