Plans include 12 HHO Generators designs, ??? Professional Military Knowledge (PMK) References: P-500-0021: ADVANCED LEADERSHIP STUDENT GUIDE: BUPERSINST 1430.16: Advancement Manual for ??? Instructions Manual to Serway and Jewett's Physics for Scientists and Engineers, 6th Edn A rocket is a missile, spacecraft, aircraft or other vehicle that obtains thrust from a rocket engine.