Editing SpaceX Merlin (section)

===Merlin 1A===
The initial version, the '''Merlin 1A''', used an inexpensive, expendable, [[Ablation|ablatively cooled]] [[carbon-fiber-reinforced polymer]] [[Composite material|composite]] nozzle and produced {{cvt|340|kN|lbf}} of thrust.
The Merlin 1A flew only twice: first on March 24, 2006, when it caught fire and failed due to a fuel leak shortly after launch,<ref name="NTmuf">{{cite news |first=Brian |last=Berger |url=http://www.space.com/missionlaunches/060719_falcon1_update.html |title=Falcon 1 Failure Traced to a Busted Nut |date=July 19, 2006 |publisher=Space.com |access-date=August 2, 2008 |archive-date=June 4, 2010 |archive-url=https://web.archive.org/web/20100604062301/http://www.space.com/missionlaunches/060719_falcon1_update.html |url-status=live }}</ref><ref name="cFfqL">{{cite news |archive-url=https://web.archive.org/web/20130303034924/http://www.spacex.com/updates_archive.php?page=0606-1206#Flight1_update |archive-date=March 3, 2013 |url-status=dead |url=http://www.spacex.com/updates_archive.php?page=0606-1206#Flight1_update |title=Findings of the Falcon return to flight board |date=July 25, 2006 |publisher=SpaceX.com}}</ref> and the second time on March 21, 2007, when it performed successfully.<ref name="MkWhi">{{cite web |title=Demo Flight 2 Flight Review Update |date=June 15, 2007 |publisher=SpaceX |archive-url=https://web.archive.org/web/20120306015017/http://www.spacex.com/F1-DemoFlight2-Flight-Review.pdf |archive-date=March 6, 2012 |url-status=dead |url=http://www.spacex.com/F1-DemoFlight2-Flight-Review.pdf }}</ref> Both times the Merlin&nbsp;1A was mounted on a [[Falcon&nbsp;1]] first stage.<ref name="merlin_wired">{{cite web |first=Loretta Hidalgo |last=Whitesides |url=http://blog.wired.com/wiredscience/2007/11/spacex-complete.html |title=SpaceX Completes Development of Rocket Engine for Falcon 1 and 9 |publisher=Wired Science |date=November 12, 2007 |access-date=February 28, 2008 |archive-date=March 23, 2008 |archive-url=https://web.archive.org/web/20080323162937/http://blog.wired.com/wiredscience/2007/11/spacex-complete.html |url-status=live }}</ref><ref name="merlin_nasaspaceflight">{{cite web |first=Braddock |last=Gaskill |url=http://www.nasaspaceflight.com/2006/08/spacex-has-magical-goals-for-falcon-9/ |title=SpaceX has magical goals for Falcon 9 |publisher=Nasa Spaceflight |date=August 5, 2006 |access-date=February 28, 2008 |archive-date=March 4, 2016 |archive-url=https://web.archive.org/web/20160304024753/http://www.nasaspaceflight.com/2006/08/spacex-has-magical-goals-for-falcon-9/ |url-status=live }}</ref>

The SpaceX turbopump was an entirely new, clean-sheet design contracted to Barber-Nichols, Inc. in 2002, who performed all design, engineering analysis, and construction; the company had previously worked on turbopumps for the [[RS-88]] (Bantam) and NASA [[Fastrac (rocket engine)|Fastrac]] engine programs. The Merlin&nbsp;1A turbopump used a unique [[Friction welding|friction-welded]] main shaft, with [[Inconel]]&nbsp;718 ends and an integral aluminum RP-1 impeller in the middle. The turbopump housing was constructed using [[investment casting]]s, with Inconel at the turbine end, aluminum in the center, and 300-series stainless steel at the LOX end. The turbine was a partial-admission (i.e., working fluid is only admitted through part of the rotation of the turbine; an arc, not the whole circumference) impulse design and turned at up to 20,000&nbsp;rpm, with a total weight of {{cvt|150|lb|kg|order=flip}}.{{citation needed|date=April 2017}}