I frowned, thinking. Pulse-detonation is pretty hot fragging stuff. Even now, decades after it was introduced, it was still a touchy thing. Anybody could make a standard jet engine—turbofan, ramjet, even SCRAMjet—but only a very few engineers could design and build a pulse-detonation drive that actually worked without blowing itself into shrapnel. I wouldn't have imagined that Hawai'i had the resources—monetary and personnel—to develop something that sophisticated.