US Companies have been using Russian rocket engines for their rockets for a long time, even during sanctions. But as I was going through the European rocket launches, I felt European rocket engines are not inferior to Russian. But then why are US companies continuing to rely on Russian rocket engines?

My assumptions are,

  1. Legacy rocket design. US companies are following the mantra, "Don't fix what's not broken." They will continue using their design unless they hit a technological limitation.

  2. European countries don't export their rocket engines.

My question is, does anyone knows anything about why US companies don't use European rocket engines?


3 Answers 3


Initially, every country that built rockets built their own. After WW2, the design of ICBMs and space rockets was related closely enough that the capability to design and build rockets was seen as having strategic value. This situation persisted throughout the Cold War.

When the Soviet Union collapsed in 1989, the US government worried about the possible consequences of lots of Russian rocket designers getting fired. What if they ended up working for regimes like Iran or North Korea?

Moreover, several on the Space Council, as well as others in the Bush Administration, saw another reason to engage the post-Soviets in a cooperative space venture: as a way to help hold the Russian nation together at a time when the Russian economy was faltering and its society was reeling. In the words of Brian Dailey, Albrecht's sucessor, "If we did not do something in this time of social chaos … in Russia, … then there would be potentially a hemorrhaging of technology … ‘away from Russia’ … to countries who may not have a more peaceful intention behind the use of those technologies."

So they started various programs to keep Russian space companies and the Russian space program afloat. This started with Space Shuttle visits to Mir. The biggest of these projects was the ISS, but US rocket companies were also encouraged to use Russian technology. US companies recognized a bargain when they saw one, and several American rockets ended up with Russian engines. There was some really good stuff available (see Geoffc's answer) for much lower prices than a newly developed engine would cost.

In 2014, the political situation changed. US-Russian relations cooled, and US companies started to look for alternatives to Russian-sourced engines. This includes license-building of Russian engines in the US, and new development.

  • $\begingroup$ Beyond Atlas using RD-180, and until 2010 Antares using NK-33, who else used Russian engines? $\endgroup$
    – geoffc
    Feb 26, 2015 at 13:05
  • $\begingroup$ Not sure, those two are the ones I'm aware of. $\endgroup$
    – Hobbes
    Feb 26, 2015 at 14:28
  • $\begingroup$ Kistler planned to use NK-33, but I'm not sure if money changed hands between them and the Russians (or between them and Aerojet for that matter, since Aerojet is the one that bought the NK-33 engines) $\endgroup$
    – Nickolai
    Feb 26, 2015 at 14:48
  • $\begingroup$ @Hobbes RD-181/193 will be the next one. South Korea uses the RD-193 which is called RD-181 now for US import on Antares. But that is what I thought. Not very much import/export of engines except really one good example. $\endgroup$
    – geoffc
    Feb 26, 2015 at 15:40
  • $\begingroup$ @geoffc Maybe because there wasn't more time between Soviet and Putin going violent? $\endgroup$
    – LocalFluff
    Aug 14, 2015 at 10:44

The primary reason is one of competence.

The Russians have a series of pretty darn good rockets.

The RD-171, a 4 engine bell, one turbopump engine (used on Zenit first stage) is an impressive Kerosene/LOX engine. It is a competitor for the F-1 used on the Saturn V in terms of capability.

The RD-180 is a 2 engine bell, smaller turbopump version of the RD-171 and as Atlas V has shown, a pretty darn good engine.

The RD-193/181 is the 1 engine bell version of the same. Orbital will be using 2 of these to replace the NK-33s on the Antares booster.

Heck, even the NK-33 built in the 1960s and 1970s is a darn good engine for today, which is why Orbital started with it.

The Russians do not do as well with LH2/LOX engines; there the US is world class.

Thus there are a number of useful engines made by the Russians that they are happy to export.

On the European side, there is the Vulcain engine used on the Ariane V, and not much else. The SRBs they use on Ariane V boosters and on the Vega light launcher are mostly equivalent to the solids that ATK can deliver.

For a national system, buying American is the best way to get funding, unless there is a really good alternative you want to use. For the Atlas V, there really is no good American alternative. Same for the RD-181 for Antares.

So it is really pragmatism. The Russians have some great engines using LOX/Kerosene and the Americans do not have good alternatives.

  • 7
    $\begingroup$ I think you also have to take into account track record. No one wants to put a satellite that cost 100-500 million (USD) and 5-10 years time on an unproven rocket. And you CANNOT put people on a rocket until it has undergone years of testing (at least in the US). There are not that many customers out there so there aren't many suppliers interested in a decade's worth of effort and expense to attempt to displace a good rocket already launching payloads into orbit. Instead the suppliers attempt to be first to market for new launch niches. $\endgroup$ Feb 25, 2015 at 23:21
  • 3
    $\begingroup$ The last hitch with the Ariane 5 was more than 10 years ago. Since then, it has flown 62 missions. Neither the Russians nor the the US have had that kind of track record recently. $\endgroup$ Feb 26, 2015 at 1:25
  • 1
    $\begingroup$ Didn't this mostly start due to a bunch of unused old Soviet-era engines lying around that could be put to use cheaper than building new ones? For instance, the NK-33s left over from the abandoned N-1 project. Wiki claims that these engines were sold to Aerojet for $1.1 M each, which is cheap for a jet engine, let alone a rocket engine. $\endgroup$
    – reirab
    Feb 26, 2015 at 6:19
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    $\begingroup$ @sharptooth: Usually the answer to "why not just copy X" boils down to "we don't have the tools to make the tools to make X". There is a very tall and narrow vertical stack in some industries, and space technologies are probably about as tall and narrow as they come. $\endgroup$
    – dotancohen
    Feb 26, 2015 at 9:37
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    $\begingroup$ @sharptooth They do. Aerojet makes them now. They licensed the IP. $\endgroup$
    – reirab
    Feb 26, 2015 at 14:58

The main reason was cost and reliability and efficiency. The Russian engines won out in all areas. As simple as that. The USA did nothing out of good will as the first reply states. It came down to economics. Also at the time Russia was able to easily build the new core segment for the proposed ISS based on there Mir Station. No other nation had any real experience with Space Stations at the time. It simply was far cheaper and saved years of time to use the Russian core module. Probably billions. Overall Russian engines simply were the best and probably still are. It was recently reported to congress it would take the USA until at least 2019 to develop and produce rocket engines to replace the present Russian engines used for Military and civilian launches in the USA even if the developers had all the money they needed. You only have to consider how long it is taking all the commercial operators to get there new rockets reliable. Swapping to a European engine also would take years and require a considerable amount of redesign of say the Atlas. I am no expert in that area.


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