"During 2017, we plan the delivery of 11 RD-180 engines [for Atlas rockets] to United Launch Alliance (ULA) and eight RD-181 motors [for US carrier rockets Antares] to Orbital ATK," Arbuzov said.

MOSCOW, April 21. /TASS/. Specialists of the Energomash Research and Production Association have launched active work to adapt the RD-180 liquid-propellant rocket engine for the new Soyuz-6 ...

Shortly thereafter, work began on a new engine, the RD-180. It would be twice as big as the NK-33, with five times the thrust of a jumbo jet. The RD-180 was not a slam dunk design, however.