Editing Liquid rocket propellant (section)

===World War II era===
Germany had very active rocket development before and during [[World War II]], both for the strategic [[V-2 rocket]] and other missiles. The V-2 used an alcohol/LOX [[liquid-propellant engine]], with [[hydrogen peroxide]] to drive the fuel pumps.<ref name=Clark2018>{{cite book |isbn = 978-0-8135-9918-2 |title = Ignition!: An Informal History of Liquid Rocket Propellants |last1 = Clark |first1 = John Drury |author-link=John Drury Clark |date = 23 May 2018 |publisher = Rutgers University Press |url=https://books.google.com/books?id=BdU4DwAAQBAJ  |pages=302}}</ref>{{rp|9}} The alcohol was mixed with water for engine cooling. Both Germany and the United States developed reusable liquid-propellant rocket engines that used a storeable liquid oxidizer with much greater density than LOX and a liquid fuel that [[Hypergolic propellant|ignited spontaneously on contact]] with the high density oxidizer.{{citation needed|date=May 2025}} 

The major manufacturer of German rocket engines for military use, the [[Hellmuth Walter Kommanditgesellschaft|HWK firm]],<ref>[http://www.walterwerke.co.uk/walter/index.htm British site on the HWK firm]</ref> manufactured the [[Ministry of Aviation (Nazi Germany)|RLM]]-numbered '''109-500'''-designation series of rocket engine systems, and either used [[T-Stoff|hydrogen peroxide]] as a monopropellant for [[Walter HWK 109-500|''Starthilfe'']] rocket-propulsive assisted takeoff needs;<ref>[http://www.walterwerke.co.uk/ato/109500.htm Walter site-page on the ''Starthilfe'' system]</ref> or as a [[Walter HWK 109-507|form of thrust]] for [[Henschel Hs 293|MCLOS-guided air-sea glide bombs]];<ref>[http://www.walterwerke.co.uk/missiles/hs293.htm Wlater site-page on the Henschel air-sea glide bomb]</ref> and used in a bipropellant combination of the same oxidizer with a [[C-Stoff|fuel mixture of hydrazine hydrate and methyl alcohol]] for [[Walter HWK 109-509|rocket engine systems intended for manned combat aircraft propulsion]] purposes.<ref>[http://www.walterwerke.co.uk/walter/motors.htm List of 109-509 series Walter rocket motors]</ref> 

The U.S. engine designs were fueled with the bipropellant combination of [[nitric acid]] as the oxidizer; and [[aniline]] as the fuel. Both engines were used to power aircraft, the [[Me 163 Komet]] interceptor in the case of the Walter 509-series German engine designs, and [[RATO]] units from both nations (as with the ''Starthilfe'' system for the Luftwaffe) to assist take-off of aircraft, which comprised the primary purpose for the case of the U.S. liquid-fueled rocket engine technology - much of it coming from the mind of U.S. Navy officer [[Robert Truax]].<ref>{{cite book|last=Braun|first=Wernher von (Estate of)|author-link=Wernher von Braun|author2=Ordway III |author3=Frederick I | others=& David Dooling, Jr.|title=Space Travel: A History|year=1985|publisher=Harper & Row|location=New York|isbn=0-06-181898-4|pages=83, 101|orig-year=1975}}</ref>