RD-8

RD-8 (РД-8)
Country of originSoviet Union
First flightApril 13, 1985
DesignerYuzhnoye Design Bureau
ManufacturerYuzhmash
ApplicationSecond Stage Vernier
Associated LVZenit
SuccessorRD-809M
StatusIn Production
Liquid-fuel engine
PropellantLOX / RG-1
Mixture ratio2.4
CycleStaged Combustion
Configuration
Chamber4
Performance
Thrust, vacuum78.45 kN (17,640 lbf)
Chamber pressure7.747 MPa (1,123.6 psi)
Specific impulse, vacuum342 s (3.35 km/s)
Burn time1100 s
Gimbal range±33°
Dimensions
Length1,500 mm (59 in)
Diameter4,000 mm (160 in)
Dry mass380 kg (840 lb)
Used in
Zenit family second stage
References
References[1][2][3][4][5][6]

The RD-8 (Russian: РД-8 and GRAU Index: 11D513) is a Soviet / Ukrainian liquid propellant rocket engine burning LOX and RG-1 (a rocket grade kerosene) in an oxidizer rich staged combustion cycle.[5][6] It has a four combustion chambers that provide thrust vector control by gimbaling each of the nozzles in a single axis ±33°.[2] It was designed in Dnipropetrovsk by the Yuzhnoye Design Bureau as the vernier thruster of the Zenit (GRAU: 11K77) second stage.[7] As such, it has always been paired with the RD-120 engine for main propulsion.[8][1]

It can only be started once, and as a high altitude engine it has a thrust of 78.45 kN (17,640 lbf) and a specific impulse of 342 s (3.35 km/s).[5][6] It is the first ever steering engine to use the staged combustion cycle, and as such is the basis for a family of planned engines for the Mayak launch vehicle family.[3]

The engine itself is built like a hollow cylinder, with a cylindrical space in the center so the RD-120 nozzle can pass through.[9]

  1. ^ a b Cite error: The named reference gunter-zenit was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference b14643-ukrainepropulsion was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference khai-aktt201301p4450 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference ukrspexport-rd8 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference yuzhnoye-rd8 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference yuzhmash-rd8 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference aviadvigatel was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference hendrickx2007p80 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference rsw-zenitstage2 was invoked but never defined (see the help page).