The SL-3, 4 and 6 launchers were derived from the R-7 (or SS-6) Sapwood ICBM, first launched in May 1957, and are responsible for the first satellites and every Soviet manned flight. The family is based on a core with four disposable strap-ons, totalling 24 main engines ignited at launch. The variations lie in the upper stages; the SL-4 Soyuz incorporates a more powerful stage 2 and the SL-6 Molniya adds a stage 3 for higher energy missions. The SL-3 Vostok was responsible for placing the first human in orbit.

R-7 FAMILY RECORD
First orbital launch: 4-Oct-1957
Number launched: 1,538 to Jun-1996, 1,478 attaining LEO
Launch sites: Tyuratam, Plesetsk
Vehicle success rate: 94.34% to Jun-1996

SOYUZ SL-4/A-2 SPECIFICATIONS

First launch: 23-Nov-1963
Number launched: 1,071 to Jun-1996, 1,037 reaching orbit
Launch sites: Tyuratam, Plesetsk
Principal uses: photorecon, manned Soyuz, Progress, remote sensing, Bion, other science; all LEO
Vehicle success rate: 96.64% to Jun-1996
Performance: LEO (220 km): 6,855 kg 51.6^o for Soyuz-U; 6,740 kg 64.8^o for Soyuz-U2
Cost: $15 million quoted 1989, R15 billion in Oct-1995
Number of stages: 2 + 4 strap-ons
Overall length: U2: 49.52 m manned (with Soyuz-TM escape tower); U: 45.22 m unmanned (with 10.14 m-long fairing)
Principal diameter: 10.3 m across fins
Launch mass: 309,700 kg U; 310,000 kg U2
Launch thrust: 5,932 kN vac U; 6,007 kN vac U2
Guidance: inertial, NPO AP is responsible for the A-family GN&C systems

SL-4/A-2 STRAP-ONS
Designations: individually B, V, G, D
Engines: RD-107 from NPO Energomash, each with four fixed chambers and two ±45^o gimbaled verniers for steering
Length: 19.8 m
Diameter: 2.68 m at base
Dry mass: each 3,770 kg
Oxidizer: liquid oxygen
Fuel: kerosene
Propellant mass: each 39,600 kg
Thrust: U: each 1,013 kN SL, 1,239 kN vac; U2: each 1,030 kN SL, 1,242 kN vac
Burn time: about 120 s

SL-4/A-2 CORE STAGE 1
Designation: Block A
Engines: single RD-108 from NPO Energomash, based on the RD-107 but with four gimbaled verniers for steering
Length: 28.75 m
Diameter: 2.95 m maximum at strap-on attach points on LOX tank; 2.15 m lower kerosene tank
Dry mass: 6,798 kg
Oxidizer: liquid oxygen
Fuel: kerosene
Propellant mass: about 94,500 kg (90,300 kg Interball 1 SL-6)
Thrust: 978 kN vac U; 1,011 kN vac U2
Burn time: 310 s (290 s Interball 1 SL-6)

SL-4/A-2 STAGE 2
Designation: Block I
Engines: RD-0110 from KB Khimautomatiki, incorporating four fixed chambers and four gimbaled verniers
Length: 8.1 m
Diameter: 2.66 m
Dry mass: 1,976 kg
Oxidizer: liquid oxygen
Fuel: kerosene
Propellant mass: about 23,000 kg (22,800 kg Interball 1 SL-6)
Thrust: 298 kN vac
Burn time: about 245 s (240 s Interball 1 SL-6)

MOLNIYA SL-6/A-2-e SPECIFICATIONS

First launch: 10-Oct-1960
Number launched: 296 to end-1995, 287 attaining LEO and 263 successfully departing LEO
Launch sites: Tyuratam, Plesetsk
Principal uses: Cosmos early warning, Molniya communications and science satellites, all in highly eccentric Earth orbits
Vehicle success rate: 88.85% to end-1995
Performance:
Molniya type (400 x 40,000 km, 63-65^o): 2,000 kg
Sun-synchronous (800 km): 1,500 kg
Prognoz-type (400 x 200,000 km, 65^o): 900 kg
Lunar delivery: 1,620 kg
Venus delivery: 1,180 kg
Mars delivery: 950 kg
Cost: $15 million for commercial launches
Number of stages: 3 + 4 strap-ons
Overall length: 43.44 m
Principal diameter: as SL-4
Launch thrust: as SL-4
Launch mass: 306,000 kg (305,480 kg for Interball 1)
Guidance: as SL-4

SL-6/A-2-e STRAP-ONS
See specifications for SL-4

SL-6/A-2-e CORE STAGE 1
See specifications for SL-4

SL-6/A-2-e STAGE 2
See specifications for SL-4

SL-6/A-2-e STAGE 3
Designation: 11D33, Block L family
Engines: Korolev bureau
Length: 2.64 m
Diameter: 2.41 m (suspended inside shroud)
Dry mass: 897 kg + 329 kg for solid propellant ullage motor package
Oxidizer: liquid oxygen
Fuel: kerosene
Propellant mass: 3,770 kg for Interball 1
Thrust: 67 kN vac
Burn time: about 200 s
Attitude control: unknown

NPO ENERGOMASH / RD-107
Designation: 11D511 Soyuz, 11D728 Molniya
Configuration: four fixed chambers with two gimbaled verniers
Application: SL-4 Soyuz and SL-6 Molniya strap-ons, SS-6 Sapwood ICBM
First flown: May-1957
Number flown: about 24,500 individual chambers
Dry mass: 1,155 kg
Engine cycle: open
Oxidizer: liquid oxygen, delivered at 226 kg/s
Fuel: kerosene, delivered at 91 kg/s
Mixture ratio: 2.48
Turbopump: single turbopump feeds four main chambers. The single 8,300 rpm shaft carries a double-sided shrouded impeller for LOX, a single-sided impeller for kerosene, a centrifugal pump for the two vernier chambers and for feeding LN₂ to the evaporator in the turbine exhaust, and a small pump to feed H₂O₂ to the gas generator. Turbine power is 3,800 kW
Thrust: 821 kN SL, 1,000 kN vac (verniers about 38 kN each)
Specific impulse: 257 s SL, 314 s vac
Combustion chamber pressure: 60 atm
Combustion chamber temperature: 3,250^oC
Burn time: 120 s, but 140 s possible

NPO ENERGOMASH / RD-108
Designation: 11D512 Soyuz, 11D727 Molniya
Configuration: four fixed chambers with four gimbaled verniers
Application: SL-4 Soyuz and SL-6 Molniya core stage 1, SS-6 Sapwood ICBM
First flown: May-1957
Number flown: 1,534 to end-1995
Dry mass: 1,250 kg
Engine cycle: open
Oxidizer: liquid oxygen, delivered at 208 kg/s
Fuel: kerosene, delivered at 84 kg/s
Mixture ratio: 2.48
Turbopump: as RD-107
Thrust: 745 kN SL, 941 kN vac
Specific impulse: 248 s SL, 315 s vac
Combustion chamber pressure: 52 atm
Burn time: up to 330 s

NPO ENERGOMASH / RD-0110
Designation: 11D55
Configuration: four fixed chambers with four gimbaled verniers
Application: SL-4 Soyuz and SL-6 Molniya stage 2, R9 missile stage 2
First flown: 19-Feb-1964
Number flown: 1,363 to end-1995 (RD-0110 + RD-0107)
Dry mass: 408 kg
Oxidizer: liquid oxygen
Fuel: kerosene
Thrust: 298 kN vac
Specific impulse: 330 s vac
Combustion chamber pressure: 70 atm
Burn time: about 245 s

KOROLEV / MOLNIYA FINAL STAGE
Designation: 11D33
Configuration: fixed single chamber
Application: SL-6 Molniya stage 3 Block L
First flown: Oct-1960?
Dry mass: 148 kg
Oxidizer: liquid oxygen
Fuel: kerosene
Thrust: 67 kN vac
Specific impulse: 340 s vac
Burn time: about 200 s