NK-15

The NK-15 (GRAU index: 11D51) was a rocket engine designed and built in the late 1960s by the Kuznetsov Design Bureau. The NK designation was derived from the initials of chief designer Nikolay Kuznetsov. The NK-15 was among the most powerful LOX/kerosene rocket engines when it was built, with a high specific impulse and low structural mass. It was intended for the ill-fated Soviet N-1 Moon rocket.

NK-15

Country of origin	Soviet Union
Date	1960s
Designer	Kuznetsov Design Bureau
Application	1st/2nd-stage engine
Predecessor	NK-9[1]
Successor	NK-33
Liquid-fuel engine
Propellant	LOX / RG-1
Mixture ratio	2.52:1 (oxidizer:fuel)
Cycle	Staged combustion
Pumps	Turbopump
Performance
Thrust, vacuum	1,544 kN (347,000 lbf)
Thrust, sea-level	1,526 kN (343,000 lbf)
Throttle range	50–105%
Thrust-to-weight ratio	126.22:1
Chamber pressure	7.85 MPa (1,139 psi)
Specific impulse, vacuum	318 s (3.12 km/s)
Specific impulse, sea-level	297 s (2.91 km/s)
Dimensions
Length	2.7 m (8 ft 10 in)
Diameter	1.5 m (4 ft 11 in)
Dry mass	1,247 kg (2,749 lb)
References
References	[2]

History

The engine equipped the N1 rocket - the first two launch attempts failed due to this engine.^[3] Its successor, the NK-33 was to be used on the N1F, an upgraded version of the N1,^[4] but the program was cancelled.^[5]

Versions

• NK-15V (GRAU index: 11D52): modified NK-15 optimized for vacuum operation, used on the second stage of the N1.

See also

• Comparison of orbital rocket engines