View source for YF-20

{{short description|Chinese rocket engine}}
{{Infobox rocket engine
|name            = YF-20
|image           = YF-20K - NMC.jpg
|image_size      =
|caption         = A YF-20K engine
|country_of_origin= [[China]]
|date            =
|first_date      =1995-06-01
|last_date       =
|designer        =[[Academy of Aerospace Liquid Propulsion Technology]]
|manufacturer    =
|purpose         =
|associated      = [[Feng Bao 1]], [[Long March 2 (rocket family)|Long March 2]], [[Long March 3 (rocket family)|Long March 3]] and [[Long March 4 rocket family|Long March 4]]
|predecessor     =
|successor       =
|status          = In Production
|type            =liquid
|oxidiser        =[[Dinitrogen tetroxide|N<sub>2</sub>O<sub>4</sub>]]
|fuel            =[[Unsymmetrical dimethylhydrazine|UDMH]]
|mixture_ratio   =
|cycle           =[[Gas-generator cycle (rocket)|Gas Generator]]
|pumps           =
|description     =
|combustion_chamber=1
|nozzle_ratio    =12.69
|thrust          =
|thrust_at_altitude=
|thrust(Vac)     ={{convert|816.3|kN|lbf|abbr=on}}
|thrust(SL)      ={{convert|731.5|kN|lbf|abbr=on}}
|throttle_range  =
|thrust_to_weight=
|chamber_pressure={{convert|7.1|MPa|psi|abbr=on}}
|specific_impulse=
|specific_impulse_vacuum={{convert|289|isp}}
|specific_impulse_sea_level={{convert|259|isp}}
|total_impulse   =
|burn_time       =160s
|restarts        =<!--leave blank if not restartable-->
|gimbal          =±10° (when integrated on the YF-21B)
|capacity        =
|dimensions      =
|length          =
|diameter        = {{convert|84|cm|in}}
|dry_weight      = {{convert|712.5|kg|lb|abbr=on}}
|used_in         = [[Feng Bao 1]] first stage and [[Long March 2C]], [[Long March 2D]], [[Long March 2E]], [[Long March 3]], [[Long March 3A]], [[Long March 3B]] and [[Long March 4A]], boosters, first stage and second stage.
|references      =<ref name=braeunig-lgmarch /><ref name=ea-yf20b /><ref name=sutton-hlpre /><ref name=mowthorpe-tmawos />
|notes           =
}}
The '''YF-20''' is a [[Government of China|Chinese]] [[liquid-fuel rocket|liquid-fuel]] [[rocket engine]] burning [[Dinitrogen tetroxide|N<sub>2</sub>O<sub>4</sub>]] and [[Unsymmetrical dimethylhydrazine|UDMH]] in a [[Gas-generator cycle (rocket)|gas generator]] cycle. It is a basic engine which when mounted in a four engine module forms the '''YF-21'''. The high altitude variation is known as the '''YF-22''' is normally paired with the [[YF-23 (rocket engine)|YF-23]] [[Vernier thruster|vernier]] to form the '''YF-24''' propulsion module for second stages. New versions when used individually for booster applications are called '''YF-25'''.<ref name=harvey-csp /><ref name=b14643-asianenginehist />
==Versions==
The basic engine has been used since the [[Feng Bao 1]] rocket and has been the main propulsion of the [[Long March 2 (rocket family)|Long March 2]], [[Long March 3 (rocket family)|Long March 3]] and [[Long March 4 rocket family|Long March 4]] families.<ref name=b14643-asianenginehist /><ref name=b14643-yfenginehist /><ref name=b14643-fb1prop />
* '''YF-20''': Core engine. Flown originally on the [[Feng Bao 1]] and [[Long March 2A]].<ref name=b14643-fb1prop /><ref name=ea-yf20 /><ref name=b14643-cz2prop />
* '''YF-20A''': Core engine.<ref name=ea-yf20a />
* '''YF-20B''' (a.k.a. '''DaFY5-1'''): Core engine, also used on the boosters.<ref name=ea-yf20b /><ref name=casc-lm3b-1999 /><ref name=casc-lm2e-1999 />
* '''YF-20C''': Core engine, also used on the boosters.
* '''YF-20D''': Core engine, also used on the boosters.
* '''YF-20E''': Core engine, also used on the boosters.
* '''YF-22''': Upper stage version with enlarged nozzle are ratio. Flown originally on the [[Feng Bao 1]] second stage with no verniers, and on the [[Long March 2A]] with the YF-23 verniers as the '''YF-24'''.<ref name=b14643-fb1prop /><ref name=b14643-cz2prop />
* '''YF-22A''': Upper stage version.
* '''YF-22B''' (a.k.a. '''DaFY20-1'''): Upper stage version.<ref name=casc-lm3b-1999 /><ref name=casc-lm2e-1999 />
* '''YF-22C''': Upper stage version.
* '''YF-22D''': Upper stage version.
* '''YF-22E''': Upper stage version.
* '''YF-25''': Booster stage version.
==Modules==
[[File:YF-24B.JPG|thumb|left|alt=A YF-24B engine|A YF-24B engine]]
While the basic engine was used multiple times, it was only used as a single engine for booster application. It is usually bundled into modules of multiple engines.<ref name=b14643-cz2prop /><ref name=b14643-cz3prop /><ref name=b14643-cz4prop />
The relevant modules for first stage application are:
* '''YF-21''': A module comprising four YF-20. Flown originally on the [[Feng Bao 1]] and [[Long March 2A]].<ref name=b14643-fb1prop /><ref name=b14643-cz2prop />
* '''YF-21A''': A module comprising four YF-20A. Improved version.
* '''YF-21B''' (a.k.a. '''DaFY6-2'''): A module comprising four YF-20B. Improved version which increased thrust by 7%.<ref name=casc-lm3b-1999 />
* '''YF-21C''': A module comprising four YF-20C. Improved version.<ref name=casc-lm3a-2011 />
* '''YF-21D''': A module comprising four YF-20D. Improved version.
* '''YF-21E''': A module comprising four YF-20E. Improved version.
The relevant modules for second stage application are:
* '''YF-24''': A module comprising an YF-22 and a [[YF-23 (rocket engine)|YF-23]] vernier. First flown on the [[Long March 2A]].<ref name=b14643-cz2prop />
* '''YF-24A''': A module comprising an YF-22A and a YF-23A verniers.
* '''YF-24B''': A module comprising an YF-22B and a YF-23B verniers.
* '''YF-24C''': A module comprising an YF-22C and a YF-23C verniers.
* '''YF-24D''': A module comprising an YF-22D and a YF-23D verniers.
* '''YF-24E''': A module comprising an YF-22E and a YF-23E verniers.<ref name=casc-lm3a-2011 />
==References==
{{reflist|30em|refs=
<ref name=b14643-asianenginehist>{{cite web |url=http://www.b14643.de/Spacerockets/Diverse/Asian_Rocket_engines/engines.htm |title=Asian space-rocket liquid-propellant engines |website=B14643.DE |author=Norbert Bgügge |access-date=2015-07-15 |url-status=dead |archive-url=https://web.archive.org/web/20150717192824/http://www.b14643.de/Spacerockets/Diverse/Asian_Rocket_engines/engines.htm |archive-date=2015-07-17 }}</ref>
<ref name=b14643-yfenginehist>{{cite web |url=http://www.b14643.de/Spacerockets_1/China/CZ-2/Propulsion/history.htm |title=YF rocket engine history |website=B14643.DE |author=Norbert Bgügge |access-date=2015-07-15 |url-status=dead |archive-url=https://web.archive.org/web/20150717181840/http://www.b14643.de/Spacerockets_1/China/CZ-2/Propulsion/history.htm |archive-date=2015-07-17 }}</ref>
<ref name=b14643-fb1prop>{{cite web |url=http://www.b14643.de/Spacerockets_1/China/FB-1/Propulsion/engines.htm |title=Propulsion FB-1 |website=B14643.DE |author=Norbert Bgügge |access-date=2015-07-15}}</ref>
<ref name=b14643-cz2prop>{{cite web |url=http://www.b14643.de/Spacerockets_1/China/CZ-2/Propulsion/engines.htm |title=Propulsion CZ-2, CZ-2C, CZ-2D |website=B14643.DE |author=Norbert Bgügge |access-date=2015-07-15}}</ref>
<ref name=b14643-cz3prop>{{cite web |url=http://www.b14643.de/Spacerockets_1/China/CZ-3/Propulsion/engines.htm |title=Propulsion CZ-3, CZ-3A CZ-3B, CZ-3C |website=B14643.DE |author=Norbert Bgügge |access-date=2015-07-15}}</ref>
<ref name=b14643-cz4prop>{{cite web |url=http://www.b14643.de/Spacerockets_1/China/CZ-4/Propulsion/engines.htm |title=Propulsion CZ-4A, CZ-4B, CZ-4C |website=B14643.DE |author=Norbert Bgügge |access-date=2015-07-15}}</ref>
<ref name=braeunig-lgmarch>{{cite web |url=http://www.braeunig.us/space/specs/lgmarch.htm |title=Long March |publisher=Rocket and Space Technology |access-date=2015-07-08}}</ref>
<ref name=casc-lm2e-1999>{{cite book |url=http://www.globalsecurity.org/space/library/report/1999/lm2echapter2.pdf |title=LM-2E User's Manual. Issue 1999 |date=1999 |publisher=[[China Aerospace Science and Technology Corporation|CASC]] |chapter=Chapter 2 &mdash; General Description to LM-2E |pages=2 |access-date=2015-07-08}}</ref>
<ref name=casc-lm3a-2011>{{cite book |url=http://www.cgwic.com/LaunchServices/Download/manual/LM-3A%20Series%20Launch%20Vehicles%20User%27s%20Manual%20Issue%202011.pdf |title=LM-3A Series Launch Vehicle User's Manual. Issue 2011 |date=2011 |publisher=[[China Aerospace Science and Technology Corporation|CASC]] |chapter=2.3 LM-3B and LM-3BE Launch Vehicles |pages=2–16 |access-date=2015-07-08}}</ref>
<ref name=casc-lm3b-1999>{{cite book |url=http://www.globalsecurity.org/space/library/report/1999/lm3bchapter2.pdf |title=LM-3B User's Manual. Issue 1999 |date=1999 |publisher=[[China Aerospace Science and Technology Corporation|CASC]] |chapter=Chapter 2 &mdash; General Description to LM-3B |pages=2 |access-date=2015-07-08}}</ref>
<ref name=ea-yf20>{{cite web |url=http://www.astronautix.com/fam/yf20.htm |title=YF-20 |publisher=Encyclopedia Astronautica |access-date=2015-07-15 |url-status=dead |archive-url=https://web.archive.org/web/20150824124334/http://www.astronautix.com/fam/yf20.htm |archive-date=2015-08-24 }}</ref>
<ref name=ea-yf20a>{{cite web |url=http://www.astronautix.com/engines/yf20a.htm |title=YF-20A |publisher=Encyclopedia Astronautica |access-date=2015-07-15 |url-status=dead |archive-url=https://web.archive.org/web/20150824113725/http://www.astronautix.com/engines/yf20a.htm |archive-date=2015-08-24 }}</ref>
<ref name=ea-yf20b>{{cite web |url=http://www.astronautix.com/engines/yf20b.htm |title=YF-20B |publisher=Encyclopedia Astronautica |access-date=2015-07-15 |url-status=dead |archive-url=https://web.archive.org/web/20150824113528/http://www.astronautix.com/engines/yf20b.htm |archive-date=2015-08-24 }}</ref>
<ref name=harvey-csp>{{cite book |chapter-url=https://books.google.com/books?id=XaqK7LOVsc0C&dq=yf-20&pg=PA231 |title=China's Space Program &mdash; From Conception to Manned Spaceflight |last=Harvey |first=Brian |chapter=Launch Centers Rockets and Engines |page=231 |publisher=Springer Science & Business Media |date=2004 |isbn=978-1852335663 |access-date=2015-07-15}}</ref>
<ref name=mowthorpe-tmawos>{{cite book |chapter-url=https://books.google.com/books?id=3QY-4UKu-qUC&dq=yf-20&pg=PA90 |title=The Militarization and Weaponization of Space |last=Mowthorpe |first=Matthew |date=2004 |publisher=Lexington Books |chapter=Chinas Military Space Program |page=90 |isbn=978-0739107133 |access-date=2015-07-15}}</ref>
<ref name=sutton-hlpre>{{cite book |chapter-url=https://books.google.com/books?id=s1C9Oo2I4VYC&dq=yf-20&pg=PA869 |title=History of Liquid Propellant Rocket Engines |last=Sutton |first=George Paul |date=November 2005 |publisher=[[AIAA]] |chapter=Liquid Rocket Propellant Engines in the People's Republic of China |page=873 |isbn=978-1563476495 |access-date=2015-07-15}}</ref>
}}
{{Rocket engines}}
{{DEFAULTSORT:YF-20}}
[[Category:Rocket engines of China]]
[[Category:Rocket engines using hypergolic propellant]]
[[Category:Rocket engines using the gas-generator cycle]]