The RD-0146 is a liquid-fuel cryogenic rocket engine developed by KBKhA Kosberg in Voronezh, Russia.
The RD-0146 is the first Russian rocket engine to burn liquid oxygen and liquid hydrogen in the expander cycle, in which turbopumps are driven by waste heat absorbed in the nozzle and combustion chamber. The RD-0146 featured the fastest-spinning turbopump of any serially produced rocket engine: the fuel turbopump spun at over 120,000 rpm. The RD-0146M variant uses liquified natural gas as a fuel instead of hydrogen, while the RD-0146D variant is projected to produce specific impulse (Isp) as high as 470 isp in a vacuum.
The engine has been proposed for use on multiple carrier rockets throughout its history. RD-0146 variants were, at various times, selected to power new upper stages for Proton, Angara, Onega (a development of Soyuz-2), and Rus-M. As of 2022, the RD-0146D is in development for use on the KVTK upper stage.
Development
In 1988, RSC Energia directed KBKhA to begin work on a new preburner-less LOx/LH2 rocket engine for use on upper stages, the RO-95.