Of Russian rocket engines, Matryoshka dolls, and Ukraine.
https://en.wikipedia.org/wiki/Matryoshka_doll
1955 a serious rival to Serguey Korolev enter the space race - Yangel.
https://fr.wikipedia.org/wiki/Mikhail_Yanguel
He beats Korolev on the ICBM front with his (murderous) R-16 but lose on the civilian space race. Because he is an ukrainian, he goes to Leonid Brezhnev - another Ukrainian - and together they outsource yangel rockets to that Soviet Republic. Which become, de facto, a space power, and build the largest and deadliest Cold War ICBM - the R-36, aptly nicknamed Satan by NATO.
Fast forward to 1976 and the decision to build Energiya Buran. Construction of the Zenit boosters is outsourced to the former Yangel shop in Ukraine. Zenit can also fly alone and replace the Proton as a heavy lifter. The RD-170 engine of 800 tons thrust and advanced technology, however, will be manufactured in Russia, making the Zenit an unfortunate Ukraine - Russia bastard rocket (you can see where this is going, hint, 2014 and Dombass). Zenit stage 2 engine, the RD-120, is licence-build in Ukraine.
The Zenit RD-171 (derived from the RD-170) is a tech wonder developed by Glushko. Four combustion chambers, 800 tons thrust total. Zenit flies in 1983-84 then Energiya (1987) and then Buran (1988) just in time for USSR to collapse and Russia to take over their rocket industry... minus the large Yangel chunk now stuck in indepandant Ukraine.
Whatever, the 90's saw a U.S gold rush on Russian advanced rocket tech.
And there come the Matryoshka dolls rockets.
The RD-171 is cut in half, 2 combustion chambers, 400 tons of thrust.
This is rebranded the RD-180.
Then the RD-180 is cut in half once again: one combustion chamber, 200 tons thrust.
This is called the RD-190 series.
So the RD-170 / RD-180 / RD-190 are very much the M. doll concept applied to rocketry.
Where it goes very strange is the respective fates of these Matryoshka engines.
The RD-171 stick with Zenit, the bastard rocket. by 1994 Russia and Ukraine team with Boeing, and all three creates... Sea Launch, where Zenits are fired from a modified oil rig stuck right under the equator for max launch efficiency. Note: Sea Launch went bankrupt twice, in 2009 and 2013, even before the Euromaidan / Dombass crisis. In 2016 the assets were taken over by a Russian company. Zenit goes home, screw Ukraine.That was Putin message. Same for ILS, by the way.
The RD-180 find its way into the EELV program... it powers the Atlas V.
As for the RD-190 series... they found their way into Orbital Sciences Antares-200 that haul Cygnus cargo ships to ISS. Antares was actually outsourced from Ukraine, who build it using... Zenit tooling.
But that engine is also to power Angara, the brand new Russian rocket to replace Proton, the bastard Zenit, the cranky Soyuz...
In the end
- Zenit & RD-170
- Atlas V & RD-180
- Angara / Antares & RD-190 - oh, and South Korea, too, forgot this one !
https://en.wikipedia.org/wiki/Naro-1
Are kind of matryoshka dolls rockets with matryoshka dolls engines.
Which mean that these engines are not only matryoshka dolls, they are also deeply interwined between Ukraine, America, and Russia... and the growing crisis between them.
Remarquably, despite things like Dombass or... Robert Mueller report over Trump / Putin "interactions", neither these engines nor the ISS have been impacted. So far, of course. Indigenous production of the RD-180 in the U.S is considered feasible, but future belongs to the brand new Vulcan without a Russian engine.
As for Ukraine, they are currently "purging" their rockets of Russians engines and components. Since they manufactured Zenit stage 2 (the RD-120) they are actually copying that engine to create their own RD-170 / 180 / 190 family of staged combustion engines, the RD-801 / 810 / 815. They will use these engines with Zenit tooling (as for Antares !) to create the Cyclone 4M and Mayak boosters. Further adding Ukrainian matrioshka dolls rockets to the US and Russian ones.
https://en.wikipedia.org/wiki/Cyclone-4M
https://en.wikipedia.org/wiki/Mayak_(rocket_family)
In the immortal words of the vulcans "Zenit. Live long, and prosper."