Nk-33 and Nk-43 Rocket Engines


The NK-33 and NK-43 rocket engines are the highest performing Liquid Oxygen/ Kerosene ever produced. They are upgraded versions of the the NK-15 and NK-15B engines which flew on the first four flights of the N-1 Soviet Moon Rocket. They were designed to provide improved thrust, reliability and restart capability.

They were designed and built by Kuznetsov Joint Stock Company which also designs aircraft engines. In the mid-1970’s, an updated N-1 was going to use the NK-33 and NK-43. Unfortunatley, the N-1 programme was cancelled. Its successor was the Energia Launch System which launched the Buran Soviet Space Shuttle.

NK-33 Rocket Engine

N1- Moon Rocket 

The N-1 used 30 NK-15 in the first stage, 8 NK-15V in the second stage. NK-15 upgraded version was called Nk33. NK-15V upgraded version was called Nk43.

NK-33 and NK-43 were going to be used in the N1 version 2 rocket called N-1F. Unfortunately the N-1F was never launched.


Kistler was going to use the NK-33 and NK-43 for their K-1 rocket. The launch vehicle would have used three NK-33s in the first stage and one NK-43 on the second stage.

Antares V1

Antares version 1 used two Nk-33 rocket engines. Antares version 2 will use Rd-181 due to limited supply of the Nk-33.

Aerojet renamed the Nk-33s as AJ26 and imported them from Russia.


Soyuz-2-1v Rocket uses the 1 x NK-33A engine in the first stage of this launch vehicle. This design uses the Soyuz core and leave out the 4 boosters. It was first launched on

The future of the NK-33 and NK-43

GenCorp Aerojet is marketting the the NK-33 and NK-43 engines (AJ26-58/59 and AJ26-60 engines). The following companies/organizations are interested/using the engines:

– Kelly Space and Technology has proposed to use the Nk-33 engines on its Astroliner RLV.

– Kistler is using the engines on its K-1 Reusable Rocket.

– NASDA is also interested in using the the NK-33 engines as the first stage of an upgraded J-class ELV.

NK-33 and NK-43 Links: