Editing Nitrous oxide (section)

===Rocket motors===
Nitrous oxide may be used as an [[oxidizing agent|oxidiser]] in a [[rocket]] motor. Compared to other oxidisers, it is much less toxic and more stable at room temperature, making it easier to store and safer to carry on a flight. Its high density and low storage pressure (when maintained at low temperatures) make it highly competitive with stored high-pressure gas systems.<ref>{{cite web|author=Berger, Bruno |date=5 October 2007 |url=http://www.spl.ch/publication/SPL_Papers/N2O_safety_e.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.spl.ch/publication/SPL_Papers/N2O_safety_e.pdf |archive-date=2022-10-09 |url-status=live |title=Is nitrous oxide safe? |publisher=Swiss Propulsion Laboratory |pages=1–2 |quote=...Self pressurizing (Vapor pressure at 20°C is ~50.1 bar...Nontoxic, low reactivity -> rel. safe handling (General safe ???)...Additional energy from decomposition (as a monopropellant: ISP of 170 s)...Specific impulse doesn't change much with O/F...[page 2] N{{ssub|2}}O is a monopropellant (as H{{ssub|2}}O{{ssub|2}} or Hydrazine...)}}</ref>

In a 1914 patent, American rocket pioneer [[Robert Goddard]] suggested nitrous oxide and gasoline as possible propellants for a liquid-fuelled rocket.<ref>Goddard, R. H. (1914) "Rocket apparatus" {{US patent|1103503}}</ref> Nitrous oxide has been the oxidiser of choice in several [[hybrid rocket]] designs (using [[solid fuel]] with a liquid or gaseous oxidiser). The combination of nitrous oxide with [[hydroxyl-terminated polybutadiene]] fuel has been used by [[SpaceShipOne]] and others. It also is notably used in [[amateur rocketry|amateur]] and [[high power rocket]]ry with various plastics as the fuel.

Nitrous oxide may also be used as a [[monopropellant rocket|monopropellant]]. In the presence of a heated [[catalyst]] at a temperature of {{convert|577|C}}, {{chem|N|2|O}} decomposes exothermically into nitrogen and oxygen.<ref>[http://spg-corp.com/nitrous-oxide-safety.html Nitrous Oxide Safety]. Space Propulsion Group (2012)</ref> Because of the large heat release, the catalytic action rapidly becomes secondary, as thermal [[Chain reaction|autodecomposition]] becomes dominant. In a vacuum thruster, this may provide a monopropellant [[specific impulse]] (''I''{{ssub|sp}}) up to 180 s. While noticeably less than the ''I''{{ssub|sp}} available from [[hydrazine]] thrusters (monopropellant, or [[Bipropellant rocket|bipropellant]] with [[dinitrogen tetroxide]]), the decreased toxicity makes nitrous oxide a worthwhile option.

The ignition of nitrous oxide depends critically on pressure. It [[deflagration|deflagrates]] at approximately {{convert|600|C}} at a pressure of 309&nbsp;psi (21&nbsp;atmospheres).<ref name="Munke">Munke, Konrad (2 July 2001) [http://hobbyspace.com/AAdmin/archive/SpecialTopics/Misc/eindhoven.pdf Nitrous Oxide Trailer Rupture], Report at CGA Seminar "Safety and Reliability of Industrial Gases, Equipment and Facilities", 15–17 October 2001, St. Louis, Missouri</ref> At 600&nbsp;{{abbr|psi|pounds per square inch}}, the required ignition energy is only 6&nbsp;joules, whereas at 130&nbsp;psi a 2,500-joule ignition energy input is insufficient.<ref>{{cite web|url=http://www.scaled.com/images/uploads/news/N2OSafetyGuidelines.pdf |title=Scaled Composites Safety Guidelines for {{chem|N|2|O}} |publisher=Scaled Composites |date=17 June 2009 |archive-url=https://web.archive.org/web/20110712044612/http://www.scaled.com/images/uploads/news/N2OSafetyGuidelines.pdf |access-date=29 December 2013 |archive-date=12 July 2011 |quote=For example, N2O flowing at 130 psi in an epoxy composite pipe would not react even with a 2500 J ignition energy input. At 600 psi, however, the required ignition energy was only 6 J.}}</ref><ref>[http://hobbyspace.com/AAdmin/archive/SpecialTopics/Misc/pratt-explosion.pdf FR-5904]. Pratt & Whitney Aircraft.</ref>