The S1.5400 (GRAU Index 11D33) was a Soviet single-nozzle liquid-propellant rocket engine burning liquid oxygen and kerosene in an oxidizer-rich staged combustion cycle,[8] being the first rocket engine to use this cycle in the world. It was designed by V. M. Melnikov, an alumnus of Isaev, within Korolev's Bureau, for the Molniya fourth stage, the Block-L.[3][4] It was also the first Soviet engine designed for start and restart in vacuum and had the highest Isp at the time of its deployment.[9]

Country of originUSSR
First flight1960-10-10[1]
Last flight2010-09-30[2]
DesignerOKB-1 V. M. Melnikov[3][4]
ApplicationUpper Stage
Associated LVMolniya[5]
Liquid-fuel engine
PropellantLOX[5] / kerosene T-1[5]
CycleStage combustion[3][4][5]
Thrust, vacuum66.69 kilonewtons (14,990 lbf)[5]
Chamber pressure5.4 MPa (780 psi)[7]
Specific impulse, vacuum340 seconds[6]
Burn timeup to 207 s[7]
Dry weight153 kilograms (337 lb)[6]
Used in
Molniya Blok-L[6]

Its development took from 1958 to 1960.[3] The first production run was started in May 1960, and it passed all the firing tests.[9] Its first flight failed before the Block-L was activated. The first success was in a Venera flight during 1961. Between 1961 and 1964 it went through an improvement program that ended up in the S1.5400A1 version (GRAU Index 11D33M). It improved thrust from 63.74 kilonewtons (14,330 lbf) to 66.69 kilonewtons (14,990 lbf) and Isp from 338.5 s to 340 s, while keeping the same mass.[6][7]

The engine used titanium alloy in its main combustion chamber to tolerate temperatures of up to 700 °C (1,292 °F). The turbopump initial spin-up is pyrotechnic. The engine is attached to a Cardan suspension, which enables it to gimbal up to 3° in two axes.[5][9]

See alsoEdit

  • Molniya - The original rocket to use the S1.5400.
  • OKB-1 - RSC Energiya is the successor of the S1.5400 designer bureau, OKB-1.


  1. ^ Pillet, Nicolas. "Liste des lancements Molnia" (in French). Kosmonavtika.com. Retrieved 2015-05-30.
  2. ^ Pillet, Nicolas. "Liste des lancements Molnia-M" (in French). Kosmonavtika.com. Retrieved 2015-05-30.
  3. ^ a b c d Sutton, George Paul (November 2005). "Section 4.2 Engine Systems". History of Liquid Propellant Rocket Engines. AIAA. p. 66. ISBN 978-1563476495.
  4. ^ a b c Eckardt, Dietrich (2014). Gas Turbine Powerhouse. Oldenbourg Wissenschaftsverlag. p. 377. ISBN 978-3110359626.
  5. ^ a b c d e f g h "Engines". RSC Enegiya. Retrieved 2015-05-30.
  6. ^ a b c d e Sutton, George Paul (November 2005). "Section 8.11 Korolev's Design Buerau, late NPO Energiya". History of Liquid Propellant Rocket Engines. AIAA. pp. 721–724. ISBN 978-1563476495.
  7. ^ a b c "S1.5400A". Encyclopedia Astronautica. Archived from the original on 2017-11-11. Retrieved 2015-05-30.
  8. ^ "S1.5400". Encyclopedia Astronautica. Archived from the original on 2017-11-11. Retrieved 2015-05-30.
  9. ^ a b c Harvey, Brian (2007). Russian Planetary Exploration: History, Development, Legacy and Prospects. Springer-Praxis. pp. 29–31. ISBN 978-0-387-46343-8.

External linksEdit

  • RSC Energia Corporation Home Page