View source for RD-180

{{short description|Russian rocket engine}}
{{Infobox rocket engine
| name                       = RD-180
| image                      = RD-180 test firing.jpg
| caption                    = RD-180 test firing at [[Marshall Space Flight Center]]
| country_of_origin          = Russia
| designer                   = [[NPO Energomash]]
| manufacturer               = NPO Energomash
| first_date                 = {{Start date|2000|05|24|df=y}}
| purpose                    = [[Booster (rocketry)|Booster]]
| predecessor                = [[RD-170]]
| status                     = Active
| cycle                      = [[Staged combustion cycle (rocket)|Staged combustion]]
| type                       = liquid
| fuel                       = [[RP-1]]
| oxidiser                   = [[LOX]]
| mixture_ratio              = 2.72 (73% {{chem|O|2}}, 27% RP-1)
| capacity                   = 
| combustion_chamber         = 2
| nozzle_ratio               = 36.87
| thrust(SL)                 = {{cvt|3830|kN}}
| thrust(Vac)                = {{cvt|4150|kN}}
| throttle_range             = 47–100%
| specific_impulse_vacuum    = {{cvt|338|isp}}
| specific_impulse_sea_level = {{cvt|311|isp}}
| chamber_pressure           = {{convert|26.7|MPa|abbr=on}}
| thrust_to_weight           = 78.44
| mass_flow                  = {{cvt|1250|kg/s}}
| burn_time                  = 270 seconds
| diameter                   = {{cvt|3.15|m}}
| length                     = {{cvt|3.56|m}}
| dry_weight                 = {{cvt|5480|kg}}
}}
[[File:RD-180 model.jpg|thumb|A model of the RD-180]]

The '''RD-180''' ({{Langx|ru|Ракетный Двигатель-180 (РД-180)|lit=Rocket Engine-180|translit=Raketnyy Dvigatel-180}}) is a [[rocket engine]] that was designed and built in Russia. It features a dual [[combustion chamber]], dual-[[nozzle]] design and is fueled by a [[RP-1]]/[[LOX]] mixture. The RD-180 is derived from the [[RD-170]] line of rocket engines, which were used in the Soviet [[Energia (rocket)|Energia launch vehicle]]. The engine was developed for use on the US [[Atlas III]] and [[Atlas V]] [[launch vehicle]]s and first flew in 2000. It was never used on any other rocket. The engine has flown successfully on all six Atlas III flights and on 99 Atlas V flights, with just a single non-critical failure in March 2016.

Atlas V is being phased out due to the national security implications of reliance on the Russian-built engine,<ref name=sn20140917>{{cite news|last1=Ferster|first1=Warren|title=ULA To Invest in Blue Origin Engine as RD-180 Replacement |url=http://www.spacenews.com/article/launch-report/41901ula-to-invest-in-blue-origin-engine-as-rd-180-replacement|archive-url=https://archive.today/20140918114236/http://www.spacenews.com/article/launch-report/41901ula-to-invest-in-blue-origin-engine-as-rd-180-replacement|url-status=dead|archive-date=18 September 2014|date=2014-09-17|publisher=SpaceNews|access-date=2014-09-19}}</ref> which became a concern after the [[Annexation of Crimea by the Russian Federation|Russian annexation of Crimea]]. In 2021, Atlas manufacturer [[United Launch Alliance]] announced that it was retiring the Atlas V and that it had already taken delivery of the RD-180 engines for the remaining rockets.<ref name="Verge">{{cite news|last1=Roulette|first1=Joey|title=ULA stops selling its centerpiece Atlas V, setting path for the rocket's retirement|url=https://www.theverge.com/2021/8/26/22641048/ula-boeing-lockheed-end-sales-atlas-v-rocket-russia-rd180|access-date=1 September 2021|publisher=The Verge|date=26 August 2021}}</ref> {{As of|2024|06}}, 16 launches remain. In 2022, Russian supplies and maintenance were discontinued as the result of trade sanctions imposed after the [[2022 Russian invasion of Ukraine]].

==Design and specifications==
[[File:Rd180schematic.png|thumbnail|Schematic of the RD-180 engine:{{ubli
 | {{legend|#fbf501|Helium}}
 | {{legend|#bee581|Low-pressure liquid oxygen}}
 | {{legend|#76c3f2|Low-pressure liquid fuel}}
 | {{legend|#0066b0|High-pressure liquid fuel}}
 | {{legend|#dc2b19|High-pressure gaseous oxygen and preburner combustion products}}
 }}
{{glossary}}
{{term|EHA}}{{defn|[[Electro-hydraulic actuator]]}}
{{term|MR control EHA}}{{defn|Mix-ratio control EHA}}
{{term|PB fuel valve}}{{defn|Pre-burner fuel valve}}
{{glossary end}}
|350x350px]]

The combustion chambers of the RD-180 share a single turbopump unit, much like in its predecessor, the four-chambered [[RD-170 (rocket engine)|RD-170]]. The RD-180 is fueled by an [[RP-1]]/[[Liquid oxygen|LOX]] mixture and uses an extremely efficient, high-pressure [[Staged combustion cycle (rocket)|staged combustion cycle]]. The engine runs with an oxidizer-to-fuel ratio of 2.72 and employs an oxygen-rich preburner, unlike typical fuel-rich US designs.

The thermodynamics of the cycle allow an oxygen-rich preburner to give a greater [[power-to-weight ratio]], but with the drawback that high-pressure, high-temperature gaseous oxygen must be transported throughout the engine. If the surfaces contacting this oxygen were bare metal, they would corrode too quickly. The RD-180 solves this problem using an inert enamel coating on all metal surfaces in contact with the hot oxygen.<ref>{{cite book|title=Reusable Booster System: Review and Assessment|date=January 2013|publisher=National Academic Press|pages=29|isbn=978-0-309-26656-7 |url=https://books.google.com/books?id=Xz1eAgAAQBAJ|access-date=23 July 2024}}</ref>

The movements of the engine nozzles are controlled by four [[hydraulic piston|hydraulic actuator]]s. The engine can be throttled from 47% to 100% of nominal thrust.<ref>{{cite book|title=Atlas V Launch Services User's Guide|date=March 2010|publisher=United Launch Alliance|location=Centennial, CO|pages=A8-9|edition=Rev. 11|url=https://www.ulalaunch.com/docs/default-source/rockets/atlasvusersguide2010.pdf|access-date=6 December 2020|archive-date=14 December 2020|archive-url=https://web.archive.org/web/20201214060045/https://www.ulalaunch.com/docs/default-source/rockets/atlasvusersguide2010.pdf|url-status=live}}</ref>

==History==
The roots of the RD-180 rocket engine extend to the Soviet [[Energia (rocket)|Energia]] launch vehicle. The RD-170, a four-chamber engine, was developed for use in the strap-on boosters for this vehicle, which ultimately launched the [[Buran (spacecraft)|Buran orbiter]]. This engine was scaled down to a two-chamber version by combining the RD-170's combustion devices with half-size turbomachinery. After successful performance on a test stand and high-level agreements between the [[Federal government of the United States|US government]] and the [[Government of Russia|Russian government]], the engines were imported to the US for use on the [[Lockheed Martin]] [[Atlas III]], which flew from 2000 to 2005. The engine has been used since 2002 on the [[United Launch Alliance]] [[Atlas V]], the successor to the Atlas III.<ref name=c4tv2000>{{cite AV media |title=The Engines That Came In From The Cold! |url=https://www.youtube.com/watch?v=MZnYr94aa9E |access-date=2014-05-19 |publisher=Channel Four Television Corporation |date=2000 }}</ref>

The engine has design features similar{{clarify|date=September 2020}} to the [[NK-33]], which was developed by a different bureau ([[Kuznetsov Design Bureau|Kuznetzov]]) nearly a decade earlier.

===2014–2015 availability concerns===
Doubts about the [[Supply chain risk management|reliability of the supply chain]] for the RD-180 arose following the [[2014 Russian military intervention in Ukraine|Russian military intervention in Ukraine]] in March 2014. For over 13 years since the engine was first used in the Atlas III launch vehicle in 2000, there was no serious jeopardy to the engine supply, despite an uneven record of US–Russian relations since the [[Cold War]]. However, worsening relations between the West and Russia after March 2014 led to several self-imposed blockages, including a short-lived judicial injunction from the US courts that was unclear whether the scope of the US [[Crimean Anschluss#Sanctions|sanctions]] covered importing the Russian engine.<ref name=tsr20140512>{{cite news|last=Foust|first=Jeff|title=Replacing the RD-180|url=http://www.thespacereview.com/article/2512/1|access-date=2014-05-13|newspaper=The Space Review|date=2014-05-12|archive-date=14 May 2014|archive-url=https://web.archive.org/web/20140514043539/http://www.thespacereview.com/article/2512/1|url-status=live}}</ref>

On 13 May 2014, Russian Deputy Prime Minister [[Dmitry Rogozin]] announced that "Russia will ban the United States from using Russian-made rocket engines for military launches"<ref name=itm20140513>{{cite news|title=Russia responds to US sanctions over Ukraine|url=http://www.itv.com/news/update/2014-05-13/russia-responds-to-us-sanctions-over-ukraine/|access-date=2014-05-13|newspaper=ITV news|date=2014-05-13|archive-date=14 May 2014|archive-url=https://web.archive.org/web/20140514050457/http://www.itv.com/news/update/2014-05-13/russia-responds-to-us-sanctions-over-ukraine/|url-status=live}}</ref>—a frequent payload of the [[United Launch Alliance|ULA]] [[Atlas V]] launch vehicle, which powers its first stage with a single RD-180 engine that is [[Evolved Expendable Launch Vehicle|expended]] after each flight.<ref>{{cite web|url=https://www.bloomberg.com/news/2014-05-13/russia-bans-rocket-engine-sales-to-u-s-military.html|title=Russia Bans Rocket Engine Sales to U.S. Military|author=Gopal Ratnam and Henry Meyer|date=13 May 2014|work=Bloomberg|access-date=28 December 2014|archive-date=14 November 2014|archive-url=https://web.archive.org/web/20141114033332/http://www.bloomberg.com/news/2014-05-13/russia-bans-rocket-engine-sales-to-u-s-military.html|url-status=live}}</ref> In response, the [[United States Air Force|US Air Force]] asked the [[Aerospace Corporation]] to evaluate alternatives for powering the Atlas 5 booster with non-RD-180 engines. Early estimates in 2014 were that it would require five or more years to replace the RD-180 on the Atlas V.<ref name=sn20140516>{{cite news |last=de Selding|first=Peter B. |title=Estimates on Time Needed to Replace RD-180 Vary Widely |url=http://www.spacenews.com/article/launch-report/40589estimates-on-time-needed-to-replace-rd-180-vary-widely |archive-url=https://archive.today/20140519111627/http://www.spacenews.com/article/launch-report/40589estimates-on-time-needed-to-replace-rd-180-vary-widely |url-status=dead |archive-date=19 May 2014 |access-date=2014-05-16 |newspaper=Space News |date=2014-05-19 }}</ref>

Even though the Russian government could cut off the supply to ULA of imported RD-180 engines, the [[US Congress]], with emerging support from the [[US Air Force|Air Force]], came to the view that it would not be advantageous to build a US production line for the RD-180, mainly because it would need a license from the Russian government. However, the US Congress in 2014 advocated a new US rocket engine program to field a new engine by 2022.<ref name=aw20140526>{{cite news|title=Support Grows For New U.S. Rocket Engine|url=http://m.aviationweek.com/space/support-grows-new-us-rocket-engine|access-date=2014-05-27|newspaper=Aviation Week|date=2014-05-26|archive-date=27 May 2014|archive-url=https://web.archive.org/web/20140527220751/http://m.aviationweek.com/space/support-grows-new-us-rocket-engine|url-status=live}}</ref>

In June 2014, [[Aerojet Rocketdyne]] proposed that the federal government "fund an all-new, U.S.-sourced rocket propulsion system", the {{convert|500000|lbf|kN|order=flip|adj=mid|-class}} thrust kerosene/[[LOX]] [[Aerojet Rocketdyne AR1|AR1 rocket engine]]. {{As of|2014|06}}, Aerojet's projection was that the cost of each engine would be under {{USD|25 million}} per pair of engines—not including the up to {{USD|1 billion}} development cost to be funded by the US Government. Aerojet believed that the AR-1 could replace the RD-180 in the US [[Evolved Expendable Launch Vehicle]] fleet, and that it would be more affordable.<ref name=aw20140603>{{cite news|last1=Butler|first1=Amy|title=Aerojet Rocketdyne Targets $25 Million Per Pair For AR-1 Engines|url=http://aviationweek.com/defense/aerojet-rocketdyne-targets-25-million-pair-ar-1-engines|access-date=2014-06-16|publisher=Aviation Week|date=2014-06-03 <!-- adding quote as AvWk material often disappears later on. -->|quote=Aerojet Rocketdyne is targeting a cost of $20–25 million for each pair of new AR-1 engines as the company continues to lobby the government to fund an all-new, U.S.-sourced rocket propulsion system ... The effort to build a new, 500,000-lb. thrust liquid oxygen/kerosene propulsion system would take about four years from contract award and cost roughly $800 million to $1 billion. Such an engine is eyed for United Launch Alliance’s (ULA) Atlas V rocket as well as Orbital’s Antares. … [we] 'believe [the AR-1 will be] on a par – if not better – than the performance of the RD-180. We also believe it is going to be more affordable,<nowiki>'</nowiki>|archive-date=1 July 2014|archive-url=https://web.archive.org/web/20140701110019/http://aviationweek.com/defense/aerojet-rocketdyne-targets-25-million-pair-ar-1-engines|url-status=dead}}</ref>

On 21 August 2014, the U.S. Air Force released an official [[request for information]] (RFI) for a replacement for the RD-180. The RFI seeks information on "booster propulsion and/or launch system material options that could deliver cost-effective, commercially-viable solutions for current and future National Security Space (NSS) launch requirements. [[Air Force Space Command]] (AFSPC) is considering an acquisition strategy to stimulate the commercial development of booster propulsion systems and/or launch systems for [[Evolved Expendable Launch Vehicle]] (EELV)-class spacelift applications." The day before, the [[United Launch Alliance]] had taken delivery of two RD-180s, the first since the [[Annexation of Crimea by the Russian Federation|Russian annexation of Crimea]]. It was not clear when or if the RD-180 would be replaced, and the RFI asked for several options including similarity to the Russian engine, whether it would come in a new configuration and the use of "alternative launch vehicles" for the EELV mission.<ref>{{cite news|url=https://www.airforcetimes.com/news/your-air-force/2014/08/21/air-force-issues-rfi-for-new-rocket-engine-to-replace-russian-made-model/|title=Air Force issues RFI for new rocket engine to replace Russian-made model|date=August 21, 2014|publisher=Air Force Times|access-date=February 11, 2023}}</ref>

In 2014, RD-Amross were selling the RD-180s (to ULA) for $23.4m each.<ref name=ReutersNov2014>[https://www.reuters.com/article/us-russia-capitalism-rockets-special-rep/special-report-in-pentagon-deal-with-russians-big-profit-for-tiny-florida-firm-idUSKCN0J22BQ20141119 Reuters ''In Pentagon deal with Russians, big profit for tiny Florida firm'' nov 2014] {{Webarchive|url=https://web.archive.org/web/20190222152240/https://www.reuters.com/article/us-russia-capitalism-rockets-special-rep/special-report-in-pentagon-deal-with-russians-big-profit-for-tiny-florida-firm-idUSKCN0J22BQ20141119 |date=22 February 2019 }}.</ref>

In January 2015, Orbital Sciences Corporation received all the necessary permissions from government bodies for the delivery of 60 engines from NPO Energomash.<ref>{{cite web|url=http://itar-tass.com/en/economy/771489|title=US to buy 60 Russian rocket engines worth $1 bln — company|website=itar-tass.com|access-date=10 April 2018|archive-date=19 January 2015|archive-url=https://web.archive.org/web/20150119214240/http://itar-tass.com/en/economy/771489|url-status=live}}</ref>

On 24 December 2015, United Launch Alliance announced that it had placed an order for more RD-180 engines to be used by the Atlas V launch vehicle, in addition to 29 engines that the company had ordered before US sanctions were imposed on Russia over Crimea, and just days after the US Congress lifted the ban on Russian engines for American rockets.{{citation needed|date=December 2020}}

===Planned US production of the RD-180 ===
There were several plans to manufacture the RD-180 in the US, but none of them came to fruition.

Under [[RD AMROSS]], Pratt & Whitney is licensed to produce the RD-180 in the United States. According to a 2005 GAO Assessment of Selected Major Weapon Programs, Pratt & Whitney planned to start building the RD-180 in the United States in 2008 with a first military launch by 2012,<ref>{{cite web |url=http://www.gao.gov/new.items/d05301.pdf |title=DEFENSE ACQUISITIONS: Assessments of Selected Major Weapon Programs |website=[[United States Government Accountability Office]] (GAO) |date=March 2005 |page=56 |access-date=4 September 2021 |archive-date=18 January 2021 |archive-url=https://web.archive.org/web/20210118080628/https://www.gao.gov/new.items/d05301.pdf |url-status=live }}</ref> but this did not occur.

United Launch Alliance (ULA) announced in February 2015 that it was considering undertaking US production of the Russian RD-180 engine at the [[Decatur, Alabama|Decatur]], Alabama, rocket stage manufacturing facility. The US-manufactured engines would be used only for government civil (NASA) and commercial launches, not for US military launches. This project was a backup plan to the new engine development work by ULA with [[Blue Origin]] on the [[BE-4]].<ref name=dd20150207>{{cite news |last1=Fleischauer |first1=Eric |title=ULA's CEO talks challenges, engine plant plans for Decatur |url=http://www.decaturdaily.com/news/ula-s-ceo-talks-challenges-engine-plant-plans-for-decatur/article_8ba49046-af4a-11e4-97ef-ff58591d43fc.html |access-date=9 February 2015 |work=Decatur Daily |date=7 February 2015 |archive-date=12 June 2017 |archive-url=https://web.archive.org/web/20170612024028/http://www.decaturdaily.com/news/ula-s-ceo-talks-challenges-engine-plant-plans-for-decatur/article_8ba49046-af4a-11e4-97ef-ff58591d43fc.html |url-status=live }}</ref>
In 2014, the Defense Department estimated that it would require approximately $1 billion and five years to begin US domestic manufacture of the RD-180 engine.<ref>{{Cite web|url=https://aviationweek.com/us-rd-180-coproduction-would-cost-1-billion|title=U.S. RD-180 Coproduction Would Cost $1 Billion &#124; Aviation Week Network|website=aviationweek.com|access-date=5 October 2021|archive-date=4 September 2021|archive-url=https://web.archive.org/web/20210904105543/https://aviationweek.com/us-rd-180-coproduction-would-cost-1-billion|url-status=live}}</ref>

Overall, by April 14, 2021 [[NPO Energomash|Energomash]] delivered 122 RD-180 rocket engines to the United States over more than 20 years.<ref>{{cite web |title=Russia hands over last RD-180 rocket engines to US under existing deal |url=https://tass.com/science/1279033 |access-date=4 September 2021 |archive-date=25 July 2021 |archive-url=https://web.archive.org/web/20210725132826/https://tass.com/science/1279033 |url-status=live }}</ref>

In an interview on August 26, 2021, ULA's CEO [[Tory Bruno]] said that three or four RD-180s were installed on Atlas&nbsp;V rockets for upcoming missions, and the rest were sitting in a warehouse. “We took early delivery, if you will, with the RD-180, so I can end that relationship and not be dependent upon [Russia] because that’s what Congress asked us to do”, he said. The 122 RD-180 engines from [[NPO Energomash|Energomash]] generated billions in revenue for Russia's space program.<ref>{{Cite web|url=https://www.theverge.com/2021/8/26/22641048/ula-boeing-lockheed-end-sales-atlas-v-rocket-russia-rd180|title=ULA stops selling its centerpiece Atlas V, setting path for the rocket's retirement|first=Joey|last=Roulette|date=26 August 2021|website=The Verge|access-date=4 September 2021|archive-date=4 September 2021|archive-url=https://web.archive.org/web/20210904093654/https://www.theverge.com/2021/8/26/22641048/ula-boeing-lockheed-end-sales-atlas-v-rocket-russia-rd180|url-status=live}}</ref>

=== Replacement options for the RD-180 ===
Several options for replacing the RD-180 on Atlas V were investigated, but ULA ultimately decided to replace the rocket with [[Vulcan Centaur]] instead.

In February 2010, despite the availability of necessary documentation and legal rights for producing RD-180 in the United States, [[NASA]] was considering development of an indigenous core-stage engine that would be "capable of generating high levels of thrust approximately equal to or exceeding the performance of the Russian-built engine". NASA desired to produce a fully operational engine by 2020 or sooner, depending on partnership with the U.S. Defense Department.<ref>{{cite web|url=http://www.spacenews.com/article/nasa-propulsion-plans-resonate-some-rocket-industry|title=NASA Propulsion Plans Resonate with Some in Rocket Industry|work=SpaceNews.com| date=26 February 2010 |access-date=28 December 2014}}</ref>

As a result of the geopolitical and US [[US Congress|political]] considerations, United Launch Alliance considered a possible replacement for the Russian RD-180 engine used on the first-stage booster of the ULA Atlas V. Formal study contracts were issued in June 2014 to a number of US rocket-engine suppliers.<ref name=sn20140917/>

In September 2014, ULA announced that it had entered into a partnership with [[Blue Origin]] to develop the [[BE-4]] [[LOX]]/[[Liquid methane|methane]] engine to replace the RD-180 on a new [[booster (rocketry)|first-stage booster]] that would [[Atlas V successor|succeed the Atlas V]]. At the time, the engine was already in its third year of development by Blue Origin, and ULA expected the new stage and engine to start flying no earlier than 2019. Two of the {{convert|550000|lbf|kN|order=flip|adj=on|lk=on}}-thrust BE-4 engines would be used on the new launch vehicle booster.<ref name=sn20140917/>

Dynetics and Aerojet Rocketdyne (AJR) also offered their [[Aerojet Rocketdyne AR1]] hydrocarbon-fueled rocket engine as replacement of the RD-180.<ref>{{Cite web |url=http://aviationweek.com/defense/aerojet-rocketdyne-targets-25-million-pair-ar-1-engines |title=Aerojet Rocketdyne Targets $25 Million Per Pair For AR-1 Engines |access-date=16 June 2014 |archive-date=1 July 2014 |archive-url=https://web.archive.org/web/20140701110019/http://aviationweek.com/defense/aerojet-rocketdyne-targets-25-million-pair-ar-1-engines |url-status=dead }}</ref><ref>{{cite web|url=http://spaceflightnow.com/news/n1410/01ar1engine/|title=Spaceflight Now – Breaking News – Aerojet Rocketdyne says AR1 engine is best fit for Atlas 5|website=spaceflightnow.com|access-date=10 April 2018|archive-date=12 September 2015|archive-url=https://web.archive.org/web/20150912101441/http://spaceflightnow.com/news/n1410/01ar1engine/|url-status=live}}</ref> ULA CEO Tory Bruno said in early 2015 that both the AR-1 option and the US manufacture of the RD-180 by ULA under license were backup options to the primary option ULA was pursuing with the Blue Origin BE-4 engine.<ref name=dd20150207/>
By March 2016, the [[US Air Force]] had signed development contracts with AJR and Blue Origin to fund development for both engines.<ref>{{Cite web|url=https://spaceflightnow.com/2016/03/07/ulas-candidates-to-replace-rd-180-engine-win-air-force-funding/|title=ULA's candidates to replace RD-180 engine win Air Force funding – Spaceflight Now|first=Stephen|last=Clark|access-date=5 October 2021|archive-date=13 August 2021|archive-url=https://web.archive.org/web/20210813044258/https://spaceflightnow.com/2016/03/07/ulas-candidates-to-replace-rd-180-engine-win-air-force-funding/|url-status=live}}</ref>

The first [[Vulcan Centaur|Vulcan]] flight with new engines occurred in January 2024.<ref>{{cite web |last=McCrea |first=Aaron |url=https://www.nasaspaceflight.com/2024/01/vulcan-launch-peregrine-inaugural-flight/ |title=Vulcan successfully launches Peregrine lunar lander on inaugural flight |date=8 January 2024 |access-date=7 April 2024 |work=NASASpaceFlight}}</ref>

As of May 25, 2020 (20 years since the first launch of the Atlas LV with RD-180), all 90 launches so far were successful.

==Applications==
During the early 1990s, [[General Dynamics]] Space Systems Division (later purchased by [[Lockheed Martin]]) acquired the rights to use the RD-180 in the [[Evolved Expendable Launch Vehicle]] (EELV) and the [[Atlas (rocket)|Atlas program]]. As these programs were conceived to support United States Government launches, as well as commercial launches, it was also arranged for the RD-180 to be co-produced by [[Pratt & Whitney]]. However, all production took place in Russia. The engine was sold by a joint venture between the Russian developer and producer of the engine [[NPO Energomash]] and Pratt & Whitney, called [[RD Amross]].

The RD-180 was first deployed on the Atlas IIA-R vehicle, which was the [[Atlas IIA]] vehicle with the Russian (hence the R) engine replacing the previous main engine. This vehicle was later renamed the [[Atlas III rocket|Atlas III]]. An additional development program was undertaken to certify the engine for use on the modular [[Common Core Booster]] primary stage of the [[Atlas V rocket]].

===Prospective uses===
RD-180 was proposed to be used<ref>{{Cite web|url=https://survincity.com/2013/08/roscosmos-designing-a-new-space-rocket-complex-rus/|title=Roscosmos designing a new space rocket complex Rus-M — Encyclopedia of safety|website=survincity.com|access-date=5 October 2021|archive-date=30 November 2020|archive-url=https://web.archive.org/web/20201130142206/https://survincity.com/2013/08/roscosmos-designing-a-new-space-rocket-complex-rus/|url-status=live}}</ref> with a new family of [[Rus-M]] Russian space launch vehicles, proposed by [[Roskosmos]] contractors,<ref>{{cite web|url=http://www.rian.ru/science/20100126/206375192.htmll |archive-url=https://archive.today/20120908103657/http://www.rian.ru/science/20100126/206375192.htmll |url-status=dead |archive-date=8 September 2012 |title=РИА Наука – РИА Новости |publisher=Rian.ru |access-date=28 December 2014 }}</ref><ref>{{cite web|url=http://www.russianspaceweb.com/ppts_lv.html|title=Rus M : RD-180|publisher=Russianspaceweb.com|access-date=28 December 2014|archive-date=27 February 2019|archive-url=https://web.archive.org/web/20190227092914/http://russianspaceweb.com/ppts_lv.html|url-status=live}}</ref> but the program was canceled by the Russian Space Agency in October 2011.<ref name="cancellation">{{cite news |url=http://spaceflightnow.com/news/n1110/07rusm/ |title=Replacement for Soyuz rocket canned by Russia |date=2011-10-07 |publisher=Spaceflight Now |access-date=2011-10-08 |archive-date=2 November 2011 |archive-url=https://web.archive.org/web/20111102064930/http://www.spaceflightnow.com/news/n1110/07rusm/ |url-status=live }}</ref>

In March 2010, Jerry Grey, a consultant to the [[American Institute of Aeronautics and Astronautics]] and [[Universities Space Research Association]] and a former professor of aerospace engineering at [[Princeton University]], suggested using the RD-180 for a prospective NASA heavy-lift launch vehicle. For those who might be concerned about too much reliance on Russia, he pointed out that RD Amross was "very close to producing a U.S.-built version of the RD-180, and with some infusion of NASA funding could be manufacturing that engine (and perhaps even a {{convert|1700000|lbf|MN|abbr=on|disp=or}} thrust equivalent of the RD-170) in a few years".<ref>{{cite web|url=http://spacenews.com/laying-foundation-human-space-exploration/|title=Laying a Foundation for Human Space Exploration - SpaceNews.com|date=29 March 2010|website=spacenews.com|access-date=10 April 2018|archive-date=5 October 2021|archive-url=https://web.archive.org/web/20211005170134/https://spacenews.com/laying-foundation-human-space-exploration/|url-status=live}}</ref>

=== 2022 Russian invasion of Ukraine ===
On February 24, 2022, Russia began [[2022 Russian invasion of Ukraine|a large-scale military invasion of Ukraine]]. Six days later on March 2, 2022, as Russia continued the invasion, they announced an end of all sales and support of the RD-180 engines to the United States, in retaliation for sanctions placed on Russia by the US for the Ukraine attack.<ref>{{Cite web |title=Russia is stopping rocket engine sales to the US and their space chief said, 'Let them fly on something else, their broomsticks' |url=https://www.msn.com/en-us/news/world/russia-is-stopping-rocket-engine-sales-to-the-us-and-their-space-chief-said-let-them-fly-on-something-else-their-broomsticks/ar-AAUzD4a |access-date=2022-03-04 |website=MSN |language=en-US}}</ref>

==See also==
* [[Comparison of orbital rocket engines]]
* [[Staged combustion cycle (rocket)|Staged combustion cycle]] used in engine
* [[RD-191]] derivative engine being developed for the [[Angara (rocket)|Angara rocket]]
* [[RD-0124]] used in the [[Soyuz-2 (rocket)|Soyuz-2.1b]]
* [[RD-107]] used in the [[R-7 Semyorka]] missiles and [[Soyuz FG]]
* [[RD-58]] upper stage [[RP-1]]/[[LOX]] engine used in the [[N1 (rocket)|N-1 rocket]], derivatives used in the [[Proton (rocket)|Proton]] and [[Zenit (rocket)|Zenit]] rockets

==References==
{{reflist}}

==External links==
{{commons category|RD-180}}
* [https://web.archive.org/web/20160915085820/http://www.astronautix.com/r/rd-180.html Astronautix.com page on RD-180]
* [http://www.npoenergomash.ru/engines/rd180/rd180_5.html RD-180 page (in Russian) at NPO Energomash]
* [http://www.lpre.de/energomash/RD-180/index.htm RD-180 specifications and design (in Russian)]
* [https://www.youtube.com/watch?v=MZnYr94aa9E The Engines That Came In From The Cold!], ''Equinox'', [[Channel Four Television Corporation]], 2000. Documentary video on Russian rocket engine development of the NK-33 and its predecessors for the N1 rocket, the development of the staged combustion cycle, and the eventual 1990s resurgence that led to the RD-180 engine sold to the US launch provider Lockheed Martin for the Atlas III. (NK-33 story starts at 24:15–26:00 (program was shuttered in 1974); the 1990s resurgence and eventual sale of the remaining engines from storage starts at 27:25; first use as RD-180 on a US rocket launch in May 2000.)

{{Rocket engines}}
{{RD-170 rocket engine family}}
{{Russian and Soviet military designation sequences}}
{{Use dmy dates|date=September 2018}}

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[[Category:Rocket engines of Russia]]
[[Category:Rocket engines using kerosene propellant]]
[[Category:Rocket engines using the staged combustion cycle]]
[[Category:Energomash rocket engines]]