Editing SpaceX Merlin (section)

==Design==
===Engine control===
SpaceX uses a triple-redundant design in the Merlin engine computers. The system uses three computers in each processing unit, each constantly checking on the others, to instantiate a [[fault-tolerant design]]. One processing unit is part of each of the ten Merlin engines (nine on the first stage, one on the second stage) used on the Falcon&nbsp;9 launch vehicle.<ref name="aw20121118">{{cite news |last=Svitak |first=Amy |title=Dragon's "Radiation-Tolerant" Design |archive-url=https://web.archive.org/web/20131203204735/http://www.aviationweek.com/Blogs.aspx?plckBlogId=Blog%3A04ce340e-4b63-4d23-9695-d49ab661f385&plckPostId=Blog%3A04ce340e-4b63-4d23-9695-d49ab661f385Post%3Aa8b87703-93f9-4cdf-885f-9429605e14df |archive-date=December 3, 2013 |url-status=dead |url=http://www.aviationweek.com/Blogs.aspx?plckBlogId=Blog%3a04ce340e-4b63-4d23-9695-d49ab661f385&plckPostId=Blog%3a04ce340e-4b63-4d23-9695-d49ab661f385Post%3aa8b87703-93f9-4cdf-885f-9429605e14df |access-date=November 6, 2013 |newspaper=Aviation Week |date=November 18, 2012 |quote=We've got computers in the Falcon&nbsp;9, we've got three computers in one unit on each engine in the Falcon&nbsp;9, so that's 30 computers right there.}}</ref>

===Turbopump===
The Merlin LOX/RP-1 [[turbopump]] used on Merlin engines 1A–1C was designed and developed by Barber-Nichols.<ref name="bn20120610">{{cite web |title=Merlin LOX/RP-1 Turbopump |url=http://www.barber-nichols.com/products/rocket-engine-turbopumps |work=website "Products" page: Rocket Engine Turbopumps |publisher=Barber-Nichols |access-date=November 22, 2012 |archive-date=March 13, 2016 |archive-url=https://web.archive.org/web/20160313145237/http://www.barber-nichols.com/products/rocket-engine-turbopumps |url-status=live }}</ref> It spins at 36,000&nbsp;[[revolutions per minute]], delivering {{convert|10000|hp}}.<ref name="swisher-20181102">{{cite interview |first=Elon |last=Musk |author-link=Elon Musk |interviewer=[[Kara Swisher]] |url=https://www.recode.net/2018/11/2/18053428/recode-decode-full-podcast-transcript-elon-musk-tesla-spacex-boring-company-kara-swisher |title=Full Q&A: Tesla and SpaceX CEO Elon Musk on Recode Decode |format=offset 01:02:08 |date=October 13, 2018 |access-date=November 2, 2018 |quote=the turbopump on the Merlin engine runs at 36,000&nbsp;rpm, it's 10,000&nbsp;hp |archive-date=November 2, 2018 |archive-url=https://web.archive.org/web/20181102115155/https://www.recode.net/2018/11/2/18053428/recode-decode-full-podcast-transcript-elon-musk-tesla-spacex-boring-company-kara-swisher |url-status=live }}</ref>

===Gas generator===
The LOX/RP-1 turbopump on each Merlin engine is powered by a fuel-rich open-cycle [[gas generator]] similar to that used in the Apollo-era [[Rocketdyne F-1]] engine.<ref name="ZRUYD">Sutton, “History of Liquid Propellant Rocket Engines”, AIAA [2006].</ref>