This page no longer updated from 31 October 2001. Latest version can be found at S5.51

S5.51 LOK engine
S5.51 LOK engine

Credit: © Mark Wade. 64,079 bytes. 555 x 390 pixels.

Government Designation: 11D68. Other Designations: S5.51. Designer: Isayev. Developed in: 1964-72. Application: Soyuz LOK lunar orbiter. Used on spacecraft: Soyuz 7K-LOK. Propellants: N2O4/UDMH Thrust(vac): 3,388 kgf. Thrust(vac): 33.20 kN. Isp: 314 sec. Burn time: 700 sec. Mass Engine: 480 kg. Length: 2.8 m. Chambers: 2 + 1. Oxidizer to Fuel Ratio: 1.85. Country: Russia. Status: Hardware. First Flight: 1969. References: 89 , 314 . Comments: Complex engine used to maneuver the LOK to a rendezvous with the LK lander in lunar orbit, then propel the LOK out of lunar orbit (large engine), and for midcourse corrections (small engine). Burn time 700 + 300 sec. Oxidizer to fuel ratio 1,85 / 1,76.

S5.51 LOK engineS5.51 LOK engine - Side view of the Isayev S5.51 engine used in the Soyuz 7K-LOK lunar orbiter.

Credit: © Mark Wade. 60,916 bytes. 385 x 511 pixels.

Back to Index
Last update 12 March 2001.
Definitions of Technical Terms.
Contact Mark Wade with any corrections or comments.
Conditions for use of drawings, pictures, or other materials from this site..
© Mark Wade, 2001 .