Editing SpaceX Merlin (section)

===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>