RD-107

The RD-107 is a type of rocket engine initially used to launch R-7 Semyorka missiles. RD-107 engines were later used on space launch vehicles based on the R-7. As of 2007, very similar RD-117 engines are used to launch the Soyuz FG, which is in active service.

Design

The RD-107 was designed under the direction of Valentin Glushko at the Gas Dynamics Laboratory-Experimental Design Bureau (OKB-456) between 1954 and 1957. It uses liquid oxygen and kerosene as propellants, with each engine comprising four combustion chambers which share a single set of turbopumps.

Production

The RD-107 and RD-108 engines are produced at a plant in Samara, Russia, under the supervision of the Privolzhskiy branch of NPO Energomash. The Privolzhsky branch was organized as a branch of OKB-456 in 1958, specifically for the manufacture of RD-107 and RD-108 engines. The branch was led by Y.D. Solovjev until 1960, then by R.I. Zelenev until 1975, then by A.F. Udalov until 1978, and is currently led by A.A. Ganin.

Versions

Modifications to the RD-107 design have led to production of several distinct versions of the engine:

• 8D74
• 8D728
• 11D511
• 14D22 (also known as the RD-107A)

Similar modifications have led to several distinct versions of the RD-108:

• 8D75
• 8D727
• 11D512
• 14D21

Work on the 14D21 and 14D22 engines started in 1986, with a preliminary design completed in 1993. These engines incorporate a new injector head design to increase specific impulse. The first launch of a Progress cargo spacecraft using a launch vehicle equipped with these engines took place in May 2001. The first human spaceflight launch utilizing these engines took place in October 2002.

Hypergolic vs. pyrotechnic ignition

Currently produced engines are ignited with a pyrotechnic ignition system. Energomash reports a new, hypergolic ignition system (on engines designated 14D21KhZ and 14D22KhZ) are ready for certification and flight tests.

Specifications

• Thrust 813 kN (183 klb_f) at liftoff
• Thrust 991 kN (223 klb_f) in vacuum
• Specific impulse 245 kgf·s/kg (2.40 kN·s/kg) at liftoff
• Specific impulse 310 kgf·s/kg (3.04 kN·s/kg) in vacuum
• Chamber pressure 5.85 MPa (848 psi)
• Propellants: Lox/kerosene

References

• LEO on the Cheap. Air University Press. October 1994. pp. 68–69. ISBN 0894991345. http://www.dunnspace.com/leo_on_the_cheap.htm. 
• "RD-107-8D74". Encyclopedia Astronautica. http://www.astronautix.com/engines/rd178d74.htm.