The Soviet NK-33 engines will be used for SpaceX's competitor's, Orbital Sciences' Antares rocket. If NASA doesn't kill that program. SpaceX has gotten so muc

The Soviet NK-33 engines will be used for SpaceX's competitor's, Orbital Sciences' Antares rocket. If NASA doesn't kill that program. SpaceX has gotten so much publicity that killing commercial ISS supply is getting harder though. But they can still downselect. You should fight against this politically. SpaceX isn't doing very high performance rocketry if you look at their engines. It's a liquid oxygen - kerosene gas generator engine, similar to first big rocket engines everywhere in the fifties. The NK-33 for example is a much higher pressure staged combustion engine meaning it gets a much better exhaust velocity and you get more payload. So are the RD-170 and RD-180 used on Zenit and Atlas respectively. In gas generator engines, a small amount of fuel and oxidizer is burnt in the gas generator to drive a turbine which drives the pump for all propellants. After the turbine the gas generator gas is exhausted. In staged combustion, you put the gas generator gas into the chamber so it is not wasted and its volume can be much higher. There doesn't exist US technology for oxygen rich kerosene staged combustion engines, so that's why either you use gas generators like SpaceX, or use Russian engines like Lockheed Martin (Nowadays United Launch Alliance) or Orbital Sciences. Boeing (Now ULA too) used an odd hydrogen gas generator for the Delta IV first stage engine. The Space shuttle main engine (SSME) was a hydrogen staged combustion engine, a technological marvel with extreme performance but also complex and very expensive. It is a wonder of the world that they got it to work reliably. EDIT: Which makes me think - Some Russian companies like NPO Energomash http://www.npoenergomash.ru/eng/ http://www.npoenergomash.ru/eng/ can perhaps be considered the Foxconns of rocketry. You can also buy propellant tanks and structures from Russian and Ukrainian companies.