RD-58

The RD-58 (Russian : Ракетный Двигатель-58, romanized:Raketnyy Dvigatel-58, lit. 'Rocket Engine 58', GRAU index: 11D58) is a rocket engine, developed in the 1960s by OKB-1, now RKK Energia. The project was managed by Mikhail Melnikov, and it was based on the previous S1.5400 engine, which was the first staged combustion engine in the world.^[1] The engine was initially created to power the Blok D stage of the Soviet Union's abortive N1 rocket.^[5] Derivatives of this stage are now used as upper stages on some Proton and Zenit rockets.^[6] An alternative version of the RD-58 chamber, featuring a shorter nozzle, was used as the N1's roll-control engine.

The RD-58 uses liquid oxygen as the oxidizer and RG-1 as fuel in an oxidizer-rich staged combustion cycle. It features a single gimbaled chamber, radial centrifugal pumps with auxiliary booster pumps, and an oxygen-rich preburner.^[7] Recent modifications include a lightweight carbon-composite nozzle extender developed by NPO Iskra.^{[8] [9] [10]}

The Buran spacecraft used two of an evolution of the RD-58M, called 17D12, as its main orbital correction engines. Instead of RG-1, it burned Syntin, and could be ignited 15 times.^{[11] [12]} It is assumed that it was the base for the RD-58S, which had practically the same specifications and powered the Blok DM-2M.^[13] But the manufacturer states that the engine is compatible with both propellants.^[1]

The current version of the engine is the RD-58M (manufacturer designation 11D58M), which has slightly reduced thrust, but increased isp. An even newer version is under development and is known as the RD-58MF (manufacturer designation 11D58MF). It will reduce thrust to 49.03 kilonewtons (11,020 lbf) to keep the same length but increase expansion ratio to 500:1. This will enable it to gain 20s of isp (to an expected 372s). It will eventually fly on the Blok DM-03.^[14] This new version of the engine will be built in the Krasnoyarsk Machine-Building Plant.^{[15] [16]} During a November 2014 interview, Vladimir Kolmykov, the Deputy General Director of the Chemical Division of Krasnoyarsk Machine-Building Plant, stated that the production of Block-DM was suspended during that year, but work on the stage and development of the RD-58MF will resume during 2015.^[17]

This engine has had many versions through the years:

• RD-58 (GRAU Index 11D58): Original version developed for the Blok D of the N1 (rocket).^{[5] [18]}
• RD-58M (GRAU Index 11D58M): Improved version developed for the Proton Blok D.^{[7] [19]}
• RD-58M (Carbon-carbon nozzle): Version of the RD-58M that replaces the regeneratively cooled nozzle for a carbon-carbon extension manufactured by NPO Iskra. Used on Zenit-3SL's Blok DM-SL since June 10, 2003 on the Thuraya 2 launch.^{[8] [9] [10]}
• RD-58MF (GRAU Index 11D58MF): Reduced thrust and increased specific impulse version expected to fly on the Proton and Zenit Blok DM-03. Will probably also use a carbon-carbon nozzle extension.^[20]
• RD-58S (GRAU Index 11D58S): Version designed to use Syntin synthetic propellant rather than RG-1. Used on the Blok DM-2M. Probably developed based on the 17D12.^{[13] [21] [22]}
• RD-58Z (GRAU Index 11D58Z): Version adapted to the Zenit Blok DM-SL.^{[9] [23]}
• 17D12: Orbital maneuvering engines (DOM) of the Buran propulsion system 17D11, burned Syntin/LOX.^{[11] [12] [24]}