RD-180 test firing.jpg
RD-180 test firing at Marshall Space Flight Center
Country of originRussia
First flight2000-05-24
DesignerNPO Energomash
ManufacturerNPO Energomash
StatusIn use
Liquid-fuel engine
PropellantLOX / RP-1
CycleStaged combustion
Nozzle ratio36.87
Thrust (vac.)4.15 MN (930,000 lbf)
Thrust (SL)3.83 MN (860,000 lbf)
Thrust-to-weight ratio78.44
Chamber pressure26.7 MPa (3,870 psi)
Isp (vac.)338 s (3.31 km/s)
Isp (SL)311 s (3.05 km/s)
Burn time270 s
Length3,560 mm (140 in)
Diameter3,150 mm (124 in)
Dry weight5,480 kg (12,080 lb)
A model of the RD-180

The RD-180 (РД-180, Ракетный Двигатель-180, Rocket Engine-180) is a rocket engine designed and built in Russia. It features a dual combustion chamber, dual-nozzle design and is fueled by a RP-1/LOX mixture. Currently, RD-180 engines are used for the first stage of the American Atlas V launch vehicle.

The RD-180 is derived from the RD-170/RD-171 line of rocket engines, which were used in the Soviet Energia launch vehicle and are still in use in the Ukrainian Zenit launch vehicles.


The roots of the RD-180 rocket engine extend back into the Soviet Energia launch vehicle project. The RD-170, a four-chamber engine, was developed for use on the strap-on boosters for this vehicle, which ultimately was used to lift the 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 performances in engine tests on a test stand and high-level agreements between the US government and the Russian government, the engines were imported to the US for use on the Lockheed Martin Atlas III, with first flight in 2000. The engine is also used on the United Launch Alliance Atlas V, the successor to the Atlas III.[1]

The engine has similar design features[clarification needed] to the NK-33, which was developed by a different bureau (Kuznetzov) nearly a decade earlier.

2014–2015 availability concerns

Doubts about the reliability of the supply chain for the RD-180 arose following the 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 never any serious jeopardy to the engine supply, despite an uneven record of US–Russian relations since the Cold War. But worsening relations between the West and Russia after March 2014 have led to several blockages, including a short-lived judicial injunction from the US courts that were unclear on the scope of the US sanctions on importing the Russian engine.[2]

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"[3]—a frequent payload of the ULA Atlas V launch vehicle, which powers its first stage with a single RD-180 engine that is expended after each flight.[4] In response, the US Air Force has asked the Aerospace Corporation to begin evaluating alternatives for powering the Atlas 5 booster stage with non-RD-180 engines. Early estimates are that it would require five or more years to replace the RD-180 on the Atlas V.[5]

Even if the Russian government does not cut off the supply to ULA of imported RD-180 engines, the US Congress, with emerging support from the Air Force, has come around to a view that it would not be advantageous to the US government to start up a US production line to produce the RD-180. However, the US Congress is advocating for the initiation of a new US hydrocarbon rocket engine program, to field a new engine by 2022.[6]

In June 2014, Aerojet Rocketdyne proposed that the US Federal government "fund an all-new, U.S.-sourced rocket propulsion system", the 2,200-kilonewton-class (500,000 lbf) thrust kerosene/LOX AR-1 rocket engine. As of June 2014, Aerojet's early projection was that the cost of each engine would be under US$25 million per pair of engines—not including the up to US$1 billion estimated 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.[7]

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 Russian annexation of Crimea. It is not clear when the replacement of the RD-180 would start, and the RFI asked input 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.[8]

In 2014, RD-Amross were selling the RD-180s (to ULA) for $23.4m each.[9]

In January 2015, Orbital Sciences Corporation have received all the necessary permissions from government bodies for the delivery of 60 engines from NPO Energomash.[10]

On 24 December 2015, United Launch Alliance announced that it 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 against Russia were introduced over Crimea, and just days after the US Congress lifted the ban on the use of Russian engines to get American ships into space.[11]

US production of the RD-180

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, rocket stage manufacturing facility. The US-manufactured engines would be used only for government civil (NASA) and commercial launches, and would not be used for US military launches. This potential project is a backup plan to the new engine development work that ULA is undertaking with Blue Origin on the BE-4.[12]

Replacement for the RD-180 engine on US Atlas launch vehicle

As a result of the geopolitical and US political considerations as 2014 progressed, United Launch Alliance initiated an effort to consider the possible replacement of the Russian-supplied 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.[13]

In September 2014, ULA announced that it has entered into a partnership with Blue Origin to develop the BE-4 LOX/methane engine to replace the RD-180 on a new first-stage booster that would 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 2,400-kilonewton (550,000 lbf)-thrust BE-4 engines will be used on the new launch vehicle booster.[13]

Dynetics and Aerojet Rocketdyne (AJR) have also offered their AR1 hydrocarbon-fueled rocket engine as replacement of the RD-180.[14][15] ULA CEO Tory Bruno has said in early 2015 that both the AR-1 option and the US manufacture of the RD-180 by ULA under license are backup options to the primary option ULA is pursuing with the Blue Origin BE-4 engine.[12] By March 2016, the US Air Force had signed development contracts with AJR and Blue Origin to provide funding toward engine development for both engines.[16]

As of January 2020, no replacement is expected to fly before 2021.[17]

Design and specifications

  Low-pressure liquid oxygen
  Low-pressure liquid fuel
  High-pressure liquid fuel
  High-pressure gaseous oxygen and preburner combustion products
Electro-hydraulic actuator
MR control EHA
Mix-ratio control EHA
PB fuel valve
Pre-burner fuel valve

The combustion chambers of the RD-180 share a single turbopump unit, much like in its predecessor, the four-chambered RD-170. The RD-180 is fueled by an RP-1/LOX mixture and uses an extremely efficient, high-pressure 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. The movements of the engine nozzles are controlled by four hydraulic actuators. The engine can be throttled from 47% to 100% of nominal thrust.[18]


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 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 to date has taken place in Russia. The engine is currently 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. 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[19] with a new family of Rus-M Russian space launch vehicles, proposed by Roskosmos contractors,[20][21] but the program was canceled by the Russian Space Agency in October 2011.[22]

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 1,700,000 lbf or 7.6 MN thrust equivalent of the RD-170) in a few years".[23]

Prospective alternative

In February 2010, despite the availability of necessary documentation and legal rights for producing RD-180 in the United States, NASA is 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 considered in 2010 to produce a fully operational engine by 2020 or sooner, depending on partnership with the U.S. Defense Department.[24]

See also


  1. ^ The Engines That Came In From The Cold!. Channel Four Television Corporation. 2000. Retrieved 19 May 2014.
  2. ^ Foust, Jeff (12 May 2014). "Replacing the RD-180". The Space Review. Retrieved 13 May 2014.
  3. ^ "Russia responds to US sanctions over Ukraine". ITV news. 13 May 2014. Retrieved 13 May 2014.
  4. ^ Gopal Ratnam and Henry Meyer (13 May 2014). "Russia Bans Rocket Engine Sales to U.S. Military". Bloomberg. Retrieved 28 December 2014.
  5. ^ de Selding, Peter B. (19 May 2014). "Estimates on Time Needed to Replace RD-180 Vary Widely". Space News. Retrieved 16 May 2014.
  6. ^ "Support Grows For New U.S. Rocket Engine". Aviation Week. 26 May 2014. Retrieved 27 May 2014.
  7. ^ Butler, Amy (3 June 2014). "Aerojet Rocketdyne Targets $25 Million Per Pair For AR-1 Engines". Aviation Week. Retrieved 16 June 2014. 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,'
  8. ^ http://www.airforcetimes.com/article/20140821/NEWS04/308210050/Air-Force-issues-RFI-new-rocket-engine-replace-Russian-made-model[dead link]
  9. ^ Reuters In Pentagon deal with Russians, big profit for tiny Florida firm nov 2014.
  10. ^ "US to buy 60 Russian rocket engines worth $1 bln — company". itar-tass.com. Retrieved 10 April 2018.
  11. ^ "McCain sees red as US gives green light for Russian RD-180 rocket engines order". Russia Today. RT. 24 December 2015. Retrieved 24 December 2015.
  12. ^ a b Fleischauer, Eric (7 February 2015). "ULA's CEO talks challenges, engine plant plans for Decatur". Decatur Daily. Retrieved 9 February 2015.
  13. ^ a b Ferster, Warren (17 September 2014). "ULA To Invest in Blue Origin Engine as RD-180 Replacement". Space News. Retrieved 19 September 2014.
  14. ^ http://aviationweek.com/defense/aerojet-rocketdyne-targets-25-million-pair-ar-1-engines
  15. ^ "Spaceflight Now - Breaking News - Aerojet Rocketdyne says AR1 engine is best fit for Atlas 5". spaceflightnow.com. Retrieved 10 April 2018.
  16. ^ http://spaceflightnow.com/2016/03/07/ulas-candidates-to-replace-rd-180-engine-win-air-force-funding/
  17. ^ [1] Archived 2018-10-18 at the Wayback Machine, Alan Boyle, 10 October 2018.
  18. ^ Atlas V Launch Services User’s Guide (PDF) (Rev. 11 ed.). Centennial, CO: United Launch Alliance. March 2010. pp. A8-9. Retrieved 7 February 2016.
  19. ^ http://survincity.com/2013/08/roscosmos-designing-a-new-space-rocket-complex-rus/
  20. ^ "РИА Наука - РИА Новости". Rian.ru. Archived from the original on 8 September 2012. Retrieved 28 December 2014.
  21. ^ "Rus M : RD-180". Russianspaceweb.com. Retrieved 28 December 2014.
  22. ^ "Replacement for Soyuz rocket canned by Russia". Spaceflight Now. 7 October 2011. Retrieved 8 October 2011.
  23. ^ "Laying a Foundation for Human Space Exploration - SpaceNews.com". spacenews.com. 29 March 2010. Retrieved 10 April 2018.
  24. ^ "NASA Propulsion Plans Resonate with Some in Rocket Industry". SpaceNews.com. Retrieved 28 December 2014.

External links

  • Astronautix.com page on RD-180
  • RD-180 page (in Russian) at NPO Energomash
  • RD-180 specifications and design (in Russian)
  • 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.)