RD-180

RD-180

RD-180 test firing at Marshall Space Flight Center
Country of origin	Russia
First flight	24 May 2000
Designer	NPO Energomash
Manufacturer	NPO Energomash
Application	Booster
Predecessor	RD-170
Status	Active
Liquid-fuel engine
Propellant	LOX / RP-1
Mixture ratio	2.72 (73% O 2, 27% RP-1)
Cycle	Staged combustion
Configuration
Chamber	2
Nozzle ratio	36.87
Performance
Thrust, vacuum	4.15 MN (930,000 lbf)
Thrust, sea-level	3.83 MN (860,000 lbf)
Throttle range	47–100%
Thrust-to-weight ratio	78.44
Chamber pressure	26.7 MPa (3,870 psi)
Specific impulse, vacuum	338 s (3.31 km/s)
Specific impulse, sea-level	311 s (3.05 km/s)
Mass flow	1250 kg/s
Burn time	270 s
Dimensions
Length	3.56 m (140 in)
Diameter	3.15 m (124 in)
Dry weight	5,480 kg (12,080 lb)

The RD-180 (Russian: РД-180, Ракетный Двигатель-180, romanized: Raketnyy Dvigatel-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. The RD-180 is derived from the RD-170/RD-171 line of rocket engines, which were used in the Soviet Energia launch vehicle. The engine was developed for use on the US Atlas III and Atlas V launch vehicles and first flew in 2000. It was never used on any other rocket. The engine has flown successfully on all six Atlas III flights and on 99 Atlas V flights, with just a single non-critical failure in March 2016.

Atlas V is being phased out due to the national security implications of reliance on the Russian-built engine,^[1] which became a concern after the Russian invasion of Crimea. In 2021, Atlas manufacturer United Launch Alliance announced that it was retiring the Atlas V and that it had already taken delivery of the RD-180 engines for the remaining rockets.^[2] As of November 2023^[update], 17 launches remain. In 2022, Russian supplies and maintenance were discontinued as the result of trade sanctions imposed after the 2022 Russian invasion of Ukraine.