On the practical application of liquid hydrogen to flight, Lemmon was proved wrong. In 1958 and 1959, decisions were made to use liquid hydrogen in the upper stage of the Centaur launch vehicle for unmanned space missions and the upper stages of the Saturn launch vehicle for manned voyages to the moon. To explain why and how this happened, and why it took so long, is the purpose of this book. A gas turbine engine, the most common form of which is the turbojet, consists of an air inlet, a rotary fan or compressor, one or more combustion chambers, a turbine driven by hot, expanding combustion gases, and a exhaust nozzle. Essentially an open duct.
Fuel is injected and burned and the hot gases expand through a nozzle to provide thrust.
Lemmon listed as borohydrides compounds containing light metals such as sodium, beryllium, aluminum, and magnesium.