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Proton was introduced in 1965 as a 2-stage vehicle capable of delivering 12,200 kg into LEO; it was rapidly superseded by 4-stage (SL-12) and 3-stage (SL-13) versions that served as the Soviet Union's most powerful launcher. It was the first not derived from a military vehicle, although the design did begin in 1962 as the UR500 ICBM.

First launch: 16-Jul-1965 (SL-9)
Number launched: 235 to end-1995
Launch sites: Baikonur
Vehicle success rate: 87.23% to end-1995
Success rate, past 25 launches: 96% to end-1995


First launch: 10-Mar-1967
Number launched: 205 to end-1995
Launch sites: Baikonur
Principal uses: geostationary, escape and Glonass navsat missions
Vehicle success rate: 87.3% to end-1995; past 25 launches: 96% to end-1995; past 50 launches: 96% to end-1995
LEO: not used for LEO missions, but vehicle places 20,000 kg in 200 km parking orbit before GTO injection
GTO (48o): 4,800 kg
GEO: 2,600 kg using Block DM-2M; 2,400 kg using Block DM & sintin; 3,200 kg using Breeze-M
Sun-synchronous: 2,800 kg (not yet flown)
Lunar delivery: 5,700 kg
Venus delivery: 5,300 kg
Mars delivery: 4,600 kg
Availability: 2 year lead time
Cost: $56 million quoted in 1992 for dedicated launch. about $40 million quoted Oct-1994, with R14-15 billion for internal flights. Quoted 1989: $35 million for dedicated GEO ($28 million GTO), $12 million dual launch, $8 million triple.
Number of stages: 4
Overall length: SL-12 57.07 m, SL-13 57.76 m (42.34 m without stage 4/payload)
Principal diameter: 7.40 m stage 1, 4.10 m upper stages
Launch mass: 690,000 kg
Launch thrust: 8.8 MN sea level
Guidance: inertial, carried in stage 4, provides 3-axis control by means unknown until payload separation commanded. Analogue control system carried by Block DM or by payload for Block D. GN&C systems provided by NPO AP. Stage 1 conversion to closed loop guidance will add 500 kg LEO by improving efficiency and reducing propellant reserve

PROTON K SL-12 (D-1-e) STAGE 1
Engines: single storable liquid non-restartable NPO Energomash RD-253 carried in six cylindrical UDMH side modules around central oxidizer tank. Steering by engine gimballing
Length: 21.1 m
Diameter: 7.4 m overall, 1.6 m cylinders around 4.1 m core
Dry mass: 31,000 kg
Oxidizer: nitrogen tetroxide (core tank)
Fuel: UDMH (side tanks)
Propellant mass: 420,000 kg
Thrust: 8.8 MN SL, 9.8 MN vac
Burn time: 130 s

PROTON K SL-12 (D-1-e) STAGE 2
Engines: four gimbaled RD-0210 liquid chambers developed by KB Khimautomatiki. Three are RD-465 and one is RD-468 version (with gas generator)
Length: 14.56 m
Diameter: 4.15 m
Dry mass: 11,700 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 156,000 kg
Thrust: 2,376 kN vac
Burn time: up to 300 s

PROTON K SL-12 (D-1-e) STAGE 3
Engine: single fixed RD-473/RD-0212 version of RD-0210 with four gimbaled verniers for steering
Length: 6.52 m
Diameter: 4.15 m
Dry mass: 4,185 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 46,600 kg
Thrust: 593.6 kN main chamber + 4 x 7.875 kN verniers
Burn time: about 250 s (stage 3 injects the payload and stage 4 into a 200 km circular, 51.6o parking orbit 10 min after launch)

PROTON K SL-12 (D-1-e) STAGE 4
Designation: Block D, DM (debut 1974), DM-2 (1982), DM-2M (1994)
Engine: 58/58M restartable single chamber developed by Korolev bureau for D/DM
Overall length: 5.37 m D/6.22 m DM-2
Principal diameter: 3.70 m
Stage mass: 17,300 kg D/18,460 kg DM-2; dry mass 2,500 kg D/3,370 kg DM-2 (dry masses include the 800 kg casing + SOZ)
Oxidizer: liquid oxygen
Fuel: kerosene or sintin
Propellant mass: 14,940 kg
Thrust: 85 kN vac kerosene; 83.5 kN vac sintin
Burn time: over 600 s total over two burns
Burn sequence: stage 4/Block D/DM-2 ignites about 80 min after stage 3 separation, making a maximum 450 s burn for injection into 36,000 km, 48o GTO. About 400 min after launch, it ignites for a maximum of 230 s at first apogee to slot the payload directly into GEO
Attitude control: D/DM-2 carries two 110-120 kg (56 kg dry) NTO/UDMH 'SOZ' thruster packages for 3-axis control during coast and for ullage. Each houses five thrusters: 2 x 22 N pitch/roll, 1 x 44 N yaw and 2 x 11 N ullage. Block DM carries Proton's control system for Glonass and GEO missions, while Block D requires the payload to provide control


The SL-13 is the 3-stage version of the SL-12; information is included here only if it differs from the 4-stage vehicle
First launch: 16-Nov-1968
Number launched: 26 to end-1995
Principal uses: large LEO spacecraft, principally space station modules
Vehicle success rate: 88.46% to end-1995
Performance: 20,000-21,000 kg LEO (51.6o), other missions not flown
Cost: about $20 million quoted 1987
Number of stages: 3
Overall length: 44.3 m + payload


The significantly uprated Proton KM (M=modernized) is planned for about 2000, replacing Energia's Block D with Khrunichev's Breeze-M for a 3,200 kg GEO capacity. It has earlier been expected that a cryogenic stage 4 would appear by 1995 for a 4,500 kg GEO, combined with improved stage 3 performance. That is now projected for post-2000, providing 4,200 kg GEO, 6,400/7,900 kg 7/28o GTO, 7,900 kg Earth escape.

Designation: Breeze-M
Engine: single fixed restartable pump-fed engine from KB Khimmach, plus 3-axis control provided by verniers
Oxidizer: nitrogen tetroxide
Fuel: UDMH

Designation: KVRB Kislorodno-Vodorodny Razgonny Block
Engine: single chamber cryogenic KVD-1M (with two verniers) capable of five burns and 7.5 h coast
Length: 8.6 m
Diameter: 4.0 m
Dry mass: 3,400 kg
Oxidizer: liquid oxygen
Fuel: liquid hydrogen
Propellant mass: up to 19,000 kg
Thrust: 69.66 kN main chamber + 2 x 1.96 kN LOX/GH2 2-axis verniers
Burn time: 450 s total; first burn starts at 650 s

Designation: 11D43
Configuration: gimbaled single chamber
Application: Proton stage 1
First flown: 16-Jul-1965
Dry mass: 1,280 kg
Length: 2.72 m
Maximum diameter: 1.50 m
Engine cycle: closed
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Feed method: 18.7 MW turbopump driven by pre-burner gas
Thrust: 1,474 kN SL, 1,745 kN vac (uprated from 1,460 kN SL, 1,635 kN vac)
Specific impulse: 317 s vac, 285 s SL
Combustion chamber pressure: 150 atm
Burn time: 130 s

Three versions of this hypergolic engine are used on Proton. Stage 2 clusters three RD-465/RD-0208/8D411 and one RD-468/RD-0211/8D412, the latter differing only by carrying the gas generator. Stage 3 employs the RD-473/RD-0212/8D49 single engine version with four verniers.
Application: SL-12/13 Proton stage 2/3
First flown: Jul-1965 (stage 2), 1967 (stage 3)
Dry mass: 566 kg
Engine cycle: closed (oxidizer pre-burner gas routed to main chamber after driving turbine)
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Feed method: 18.7 MW turbopump driven by pre-burner gas
Thrust: 594 kN vac (stage 2), 593.6 kN vac (stage 3, plus 31.5 kN added by four verniers)
Specific impulse: 327.4 s vac (stage 2), 325.3 s vac (stage 3)
Combustion chamber pressure: 148 atm
Burn time: 210 s

The engine provides a direct GEO and planetary trajectory injection capability. There are two versions flying: the standard kerosene version and one using 'sintin' for higher Isp. Sintin is known only as a synthetic hydrocarbon-based fuel. Performance and overall dimensions are as given here for the sintin 11D58M.
Application: SL-12 Proton stage 4, SL-16 Zenit stage 3?, Buran OMS
First flown: 1967
Dry mass: 303 kg
Length: 2.27 m
Diameter: 1.17 m
Oxidizer: liquid oxygen
Fuel: kerosene or sintin
Thrust: 85 kN vac kerosene; 83.5 kN vac sintin
Specific impulse: 352 s vac kerosene; 362 s vac sintin
Combustion chamber pressure: 76.4 atm kerosene; 78.4 atm sintin
Burn time: 600 s in multiple burns

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