Long March

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THE LONG MARCH FAMILY

DF-3: Development of the original DF-3 missile was undertaken personally by Chien Hue Shen, the father of Chinese rocketry, but faced insurmountable technical and management difficulties. It was cancelled and replaced by the DF-4.
DF-2A: Extended range version of DF-2.
DF-2: (1966) First Chinese IRBM, the DF-2 was launched in 1966 with a 20 kt warhead from Shaunchengtzu, 800 km to Lop Nor, where the warhead successfully exploded.
CZ-1: (1970) Also known as Long March 1. Launch vehicle derived from DF-3 IRBM.
FB-1: (1972) Launch vehicle derived from DF-5 ICBM. Very similar to CZ-2C.
CZ-2C: (1975) Also known as Long March 2. Launch vehicle derived from DF-5 ICBM.
CZ-3: (1984) Also known as Long March 3. Based on CZ-2C but with the addition of H-8 cryogenic third stage (the first cryogenic propulsion outside US/ESA).
CZ-1C: Also known as Long March 1. As CZ-1 but with a liquid propellant third stage.
CZ-1D: Also known as Long March 1. As CZ-1 but exhibiting uprated performance.
CZ-1M: Also known as Long March 1. As CZ-1 but with Italian solid propellant third stage.
CZ-4A: (1988) Also known as Long March 4. Utilizes the first two stages of the CZ-3A with a new storable propellant upper stage.
CZ-2E: (1990) Also known as Long March 2. Based on CZ-2C with stretched/uprated first stage, incorporation of a new second stage, and the addition of four liquid propellant strap-ons. Most powerful of the CZ-2 range.
CZ-2D: (1992) Also known as Long March 2. As CZ-4A but less third stage.
CZ-3A: (1994) Also known as Long March 3. Based on CZ-3 with stretched/uprated first stage, off-loaded second stage, and incorporation of uprated H-18 cryogenic third stage.
CZ-3B: (1996) Also known as Long March 3. As CZ-3A but with the addition of CZ-2E's four liquid strap-ons.
CZ-3C: Also known as Long March 3. As CZ-3B except with only two strap-ons.
CZ-4B: (1999) Also known as Long March 4. As CZ-4A but with uprated third stage.
CZ-2F: (1999) Man-rated version of CZ-2E, designed for launch of the Shenzhou spacecraft.

Chang Zheng = Long March
Dong Feng = East Wind
Feng Bao = Storm


LONG MARCH FAMILY RECORD
First launch: 24-Apr-1970
Number launched: 41 to Jul-1996
Launch sites: Xichang, Jiuquan and Taiyuan
Vehicle success rate: 87.8% to Jul-1996



CZ-1 SPECIFICATIONS

First launch: 24-Apr-1970
Number launched: 2 to end-1995
Launch sites: Jiuquan
Principal uses: small payloads to LEO
Vehicle success rate: 100%
Performance: 300 kg into 440 km, 70o
Number of stages: 3
Overall length: 30.45 m
Principal diameter: 2.25 m
Launch mass: 81,600 kg
Launch thrust: 1,101 kN sea level
Guidance: strap-down inertial. Vanes in stages 1/2 exhausts generate control forces

CZ-1 STAGE 1
Engines: YF-2A with four fixed chambers, liquid hypergolic bipropellant, single start; four exhaust steering vanes
Length: 17.835 m
Diameter: 2.25 m
Oxidizer: nitric acid
Fuel: UDMH
Propellant mass: about 60,000 kg
Thrust: 1,101 kN SL
Burn time: about 130 s

CZ-1 STAGE 2
Engines: YF-3 with two fixed chambers, liquid hypergolic bipropellant, single start; exhaust steering vanes
Length: 5.35 m
Diameter: 2.25 m
Dry mass: 2,650 kg
Oxidizer: nitrogen tetroxide (possibly nitric acid)
Fuel: UDMH
Propellant mass: 12,130 kg (12,200 kg for CZ-1D; 13,200 kg for CZ-1M)
Thrust: 294 kN vac
Burn time: about 126 s

CZ-1 STAGE 3
Motor: GF-02 solid spun at 180 rpm
Length: about 2 m
Diameter: 0.77 m
Propellant: solid
Propellant mass: about 1,800 kg
Thrust: 29 kN?
Burn time: not available


CZ-1C

The Chinese noted in 1985 that a CZ-1 variant with a liquid stage 3 was under development, but it is now not expected to appear. Few specifications were released. Performance: 400 kg into 600 km, 70o; 400 kg into 400 km Sun-synchronous; 600 kg into 300 km, 70o. Overall length 33 m; launch mass 88,000 kg.


CZ-1D SPECIFICATIONS

Number launched: 0
Launch sites: Jiuquan
Performance: 700-750 kg into 300 km, 57o
Number of stages: 3
Overall length: 28.22 m
Principal diameter: 2.25 m
Launch mass: 81,000 kg
Launch thrust: 1,101 kN sea level
Guidance: as CZ-1

CZ-1D STAGE 1
As CZ-1.

CZ-1D STAGE 2
The fixed YF-3 engines with jet vanes for steering are reportedly replaced by gimbaled engines. Specifications as for CZ-1 except propellant mass is 12,200 kg.

CZ-1D STAGE 3
Solid propellant but few specifications available. Vehicle capability indicates enhanced performance over original CZ-1 stage 3 but below that of CZ-1M.
Motor: Chinese solid. 3-axis controlled by cold gas N2 thruster system
Length: about 2 m
Diameter: 0.77 m
Mass at ignition: 875 kg
Propellant mass: 625 kg
Thrust: 29 kN?
Burn time: not available

CZ-1D FAIRING
A 3.99 m long, 2.05 m diameter fairing is available, creating a payload envelope 1.56 m diameter at the base, tapering to 1.00 m diameter at 2.00 m high.


CZ-1M

A CZ-1M variant was first offered in 1987 incorporating the Italian IRIS solid propellant third stage, which would not be available until 1990 at the earliest (first flight made 1992). Performance: 900 kg into 300 km, 57o circular; 830 kg into 300 km, 70o circular; 450 kg into 903 km, 99o Sun-synchronous. Overall length 29.6 m; launch mass 85,000 kg.


CZ-2C SPECIFICATIONS

First launch: 26-Nov-1975
Number launched: 14 to end-1995
Launch sites: Jiuquan (Xichang planned for GTO; Taiyuan planned for Iridium)
Principal uses: medium-class payloads into LEO; recoverable Earth resources and mg capsule launcher
Vehicle success rate: 100%
Performance: (from Jiuquan, unless otherwise noted)
Sun-synchronous (98o): 750 kg into 900 km, 1,200 kg into 200 x 900 km
LEO (63.4o): 2,000 kg into 185 x 400 km; 500 kg into 1,000 x 39,500 km with CPKM kick stage
GTO from Xichang (28.2o): 1,440 kg using CPKM
Number of stages: 2 (+ kick stages available)
Overall length: 35.1 m, 38.4 m multi-payload, long-fairing version
Principal diameter: 3.35 m
Launch mass: 191,000 kg
Launch thrust: 2,785 kN sea level
Guidance: fully inertial with gimbaled platform

CZ-2C STAGE 1
Designation: L-140
Engines: four YF-20 clustered as YF-21, liquid hypergolic bipropellant, single start, gimbaled for steering
Length: 20.52 m
Diameter: 3.35 m
Dry mass: 9,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 142,000 kg
Thrust: 2,785 kN SL
Burn time: 132 s

CZ-2C STAGE 2
Designation: L-35
Engines: YF-24 assembly of single fixed YF-22 liquid hypergolic bipropellant, single start; and four gimbaled YF-23 verniers for steering
Length: 7.50 m
Diameter: 3.35 m
Dry mass: 4,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 35,000 kg
Thrust: 761.9 kN vac
Burn time: 110 s (verniers continue to burn for further 190 s)

CZ-2C FAIRING
The payload separates 430 s after launch as the stage 2 verniers shut down. 3-axis stabilization yields <0.35o/s angular rate at separation. Last stage performs retro-maneuver after separation. Standard fairing is 3.35 m diameter, 7.125 m high, providing 3.07 m diameter, 5 m high envelope. Sweden's Freja was carried in a 2.2 m diameter, 1.7 m high cylindrical adapter below FSW. A 4-satellite version is available, 2.25 m diameter x 8.7 m long, with the top satellite deployed forwards conventionally and up to three lower payloads ejected through doors frisbee-style. Payload test levels are 150 dB acoustic for 120 s, 11 g longitudinal/2 g lateral acceleration and 70 g shock for 6-10 ms.


CZ-2D SPECIFICATIONS

First launch: 9-Aug-1992
Number launched: 2 to end-1995
Launch sites: Jiuquan and Taiyuan
Principal uses: medium-class payloads into LEO and Sun-synchronous polar orbits
Vehicle success rate: 100%
Performance:
LEO (50o/90o): 3,400/2,750 kg into 200 km; 1,550/1,175 kg into 400 km
Sun-synchronous: 2,000 kg into 500 km; 850 kg into 800 km
Number of stages: 2
Overall length: 38.31 m (FSW-2 version)
Principal diameter: 3.35 m
Launch mass: 231,670 kg (FSW-2 version)
Launch thrust: 2,961 kN sea level
Guidance: all-inertial

CZ-2D STAGE 1
As CZ-4A but fins deleted and burn time 153 s.

CZ-2D STAGE 2
As CZ-4A but burn times 115 s main/145 s verniers.


CZ-2E SPECIFICATIONS

First launch: 16-Jul-1990
Number launched: 7 to end-1995
Launch sites: Xichang (potentially Jiuquan)
Principal uses: medium-class payloads into LEO and Sun-synchronous polar orbits
Vehicle success rate: 100%
Performance:
LEO (28.5o): 8,800 kg into 200 km; 7,200 kg into 400 km
GTO: 3,140 kg using Star 63F PKM, 3,460 kg using EPKM
Availability: 33 months lead time
Cost: $60 million into LEO quoted 1995
Number of stages: 2 + 4 strap-ons
Overall length: 49.7 m with standard 10.5 m fairing, 51.2 m with 12 m fairing
Principal diameter: 3.35 m
Launch mass: 462,000 kg
Launch thrust: 5,923 kN sea level
Guidance: inertial system employing 3-axis gyro package and digital computer carried in Vehical Equipment Bay at top of stage 2. Includes radio-destruct and self-destruct command system. 380-400 MHz telemetry system employs two 15 W tranmitters in the VEB and stage 2 intertank. Radar transponders for tracking

CZ-2E STRAP-ONS
Designation: LB-40
Engines: single YF-20B liquid hypergolic bipropellant, single start
Length: 15.6 m
Diameter: 2.25 m
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: each 38,000 kg
Thrust: each 740.35 kN SL
Burn time: 125.8 s, separate 127.3 s using lateral solids

CZ-2E STAGE 1
Designation: L-180
Engines: four YF-20B clustered as YF-21B, liquid hypergolic bipropellant, single start, gimbaled for steering
Length: 23.70 m
Diameter: 3.35 m
Dry mass: 10,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 187,000 kg
Thrust: 2,961 kN SL
Burn time: 158.9 s, stage 2 ingnites at 159.7 s & separates at 160.4 s

CZ-2E STAGE 2
Designation: L-90
Engines: YF-24B assembly of 1 x YF-22B + 4 x YF-23B
Length: 15.52 m
Diameter: 3.35 m
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 86,000 kg
Thrust: 788.4 kN vac
Burn time: 300 s (verniers continue for further 413 s)
Attitude control: stage 2 employs a hydrazine monopropellant attitude control system (4 x 45 N pitch thrusters, 2 x 45 N yaw, 4 x 11 N roll); it ensures correct attitude after stage shut down before two pairs of small solids at the forward end fire to spin the vehicle up to 5-7 rpm for payload separation. It then performs a collision avoidance maneuver

CZ-2E FAIRING/PAYLOAD ACCOMODATION
A standard 10.5 m, 4.2 m diameter fairing is used, creating a 3.8 m diameter payload envelope, but the cylindrical section can be lengthened to create an 11.95 m long version. The cap is glass fiber, the remainder aluminum honeycomb. Eight doors provide assess. Four aluminum alloy adapters are available. Separation at 0.9 m/s is effected by 12 springs; two microswitches signal departure. Connectors can provide pyrotechnic ignition commands and payload telemetry through the vehicle. Fairing maintains 15-25oC, humidity below 55%, held from encapsulation until 5 min before launch.
Acceleration load: 4.0 g max stage 1 longitudinal (lateral 0.6 g); 5.2 g max stage 2 longitudinal
Acoustic load: 142 dB total (max at launch/transonic); payloads should be qualified to 146 dB for 120 s


CZ-2F

Man-rated version of CZ-2E, designed for launch of the Shenzhou spacecraft. Little difference externally. Modifications were related to improved redundancy of systems, strengthened upper stage to handle large 921-1 spacecraft fairing and launch escape tower. President Jiang Zemin gave the name Shenjian (Divine Arrow) to the CZ-2F after the successful launch of the Shenzhou-3 mission.


CZ-3 SPECIFICATIONS

First launch: 29-Jan-1984
Number launched: 9 to end-1995
Launch sites: Xichang
Principal uses: medium-class payloads into GTO
Vehicle success rate: 77.8%
Performance:
GTO: 1,400 kg (31.1o); 1,340 kg (28.5o)
LEO (31.1o): 5,000 kg into 200 km; 2,500 kg into 1,200 km
Cost: about $25-35 million
Number of stages: 3
Overall length: 43.85 m
Principal diameter: 3.35 m
Launch mass: 204,000 kg
Launch thrust: 2,785 kN sea level
Guidance: inertial avionics housed in equipment bay on forward end of stage 3. TT&C system transmits on 400 MHz, 3 GHz, and 5 GHz. Stage 1 does not transmit telemetry but data recorders are recovered from the downrange wreckage

CZ-3 STAGE 1
As CZ-2C.

CZ-3 STAGE 2
Designation: L-35
Engines: YF-24 assembly of single fixed YF-22 liquid hypergolic bipropellant, single start; and four gimbaled YF-23 verniers for steering
Length: 9.71 m
Diameter: 3.35 m
Dry mass: 4,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 35,000 kg
Thrust: 765.85 kN vac
Burn time: 110 s (verniers continue to burn for further 190 s)

CZ-3 STAGE 3
Designation: H-8
Engines: cryogenic YF-73 with four chambers fed by single turbopump
Length: 7.48 m
Diameter: 2.25 m
Dry mass: 2,000 kg
Oxidizer: liquid oxygen
Fuel: liquid hydrogen
Propellant mass: 8,500 kg
Thrust: 44.15 kN vac
Burn time: about 800 s maximum total in two burns of 500 s + 300 s
Attitude control: hydrazine thrusters maintain 3-axis control, providing <1.4o release angle accuracy. A stage retro system initiates separation

CZ-3 FAIRING/PAYLOAD ACCOMODATION
Two glass fiber fairing options are available: 5.84 m long/2.60 m diameter or 7.27/3.00 m, creating 2.32 m and 2.72 m diameter envelopes, respectively. The aluminum alloy honeycomb payload mount is attached to the stage 3 equipment bay, and on its forward face to one of two payload adapters. Two explosive bolts release the payload's restraining clampband and 0.1 s later stage 3 fires a retro system for a 1.6 m/s separation rate.


CZ-3A SPECIFICATIONS

First launch: 8-Feb-1994
Number launched: 2 to end-1995
Launch sites: Xichang
Principal uses: Atlas 1-class payloads into GTO
Vehicle success rate: 100%
Performance:
GTO (28.5o): 2,300 kg
LEO (28.5o): about 8,500 kg
Number of stages: 3
Overall length: 52.52 m
Principal diameter: 3.35 m
Launch mass: 240,000 kg
Launch thrust: 2,961 kN sea level
Guidance: strap-down inertial platform (CALT)

CZ-3A STAGE 1
Designation: L-180
Engines: four YF-20B clustered as YF-21B, liquid hypergolic bipropellant, single start, gimbaled for steering
Length: 23.075 m
Diameter: 3.35 m
Dry mass: 10,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 170,000 kg
Thrust: 2,961 kN SL
Burn time: about 130 s

CZ-3A STAGE 2
Designation: L-35
Engines: YF-24B assembly of single fixed YF-22B liquid hypergolic bipropellant, single start; and four gimbaled YF-23B verniers for steering
Length: 11.53 m
Diameter: 3.35 m
Dry mass: 4,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 29,600 kg
Thrust: 788.4 kN vac
Burn time: 110 s (verniers continue to burn for further 190 s)

CZ-3A STAGE 3
Designation: H-18
Engines: two YF-75 cryogenic dual start
Length: 8.835 m
Diameter: 3.00 m
Oxidizer: liquid oxygen
Fuel: liquid hydrogen
Propellant mass: 17,600 kg
Thrust: 156.9 kN vac
Burn time: about 470 s total in 2 burns
Attitude control: hydrazine thruster system for 3-axis control

CZ-3A FAIRING
An 8.89 m long, 3.35 m diameter fairing is available, creating a 3.00 m diameter, 5.25 m high payload envelope.


CZ-3B and CZ-3C SPECIFICATIONS

CZ-3C is identical to the CZ-3B execpt that only two strap-ons will be utilized.
First launch: 14-Feb-1996 (3B)
Number launched: 1 to May-1996
Launch sites: Xichang
Principal uses: large GTO payloads, planetary capability
Vehicle success rate: 0%
Performance:
GTO (28.0o): 4,850 kg
LEO: 12,000 kg
GEO: about 2,000 kg
Sun-synchronous: 5,700 kg
Lunar delivery: about 5,500 kg
Mars/Venus delivery: about 4,500 kg
Number of stages: 3 + 4 strap-ons (3C: 3 + 2 strap-ons)
Overall length: about 55.55 m
Principal diameter: 3.35 m
Launch mass: 425,000 kg (3C: 329,000 kg)
Launch thrust: 5,923 kN sea level (3C: 4,442 kN SL)

CZ-3B STRAP-ONS
As CZ-2E.

CZ-3B STAGE 1
As CZ-3A.

CZ-3B STAGE 2
As CZ-3A, although one 1992 illustration suggests the stage is stretched.

CZ-3B STAGE 3
As CZ-3A.

CZ-3B FAIRING
4.2 m diameter, with 3.8 m diameter envelope.


CZ-4A SPECIFICATIONS

First launch: 6-Sep-1988
Number launched: 2 to end-1995
Launch sites: Jiuquan and Taiyuan
Principal uses: medium-class payloads into Sun-synchronous polar orbits; typically meteorological and Earth observation satellites
Vehicle success rate: 100%
Performance:
LEO: 4,000 kg into 200 km; 1,000 kg into 1,000 km; 3,800 kg into 400 km, 70o
Sun-synchronous (900 km, 96o): 1,500 kg
Number of stages: 3
Overall length: 41.895 m
Principal diameter: 3.35 m
Launch mass: 249,000 kg
Launch thrust: 2,961 kN sea level
Guidance: all inertial

CZ-4A STAGE 1
Designation: L-180
Engines: four YF-20B clustered as YF-21B, liquid hypergolic bipropellant, single start, gimbaled for steering
Length: 24.66 m
Diameter: 3.35 m
Dry mass: 10,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 183,200 kg
Thrust: 2,961 kN SL
Burn time: 150.8 s

CZ-4A STAGE 2
Designation: L-35
Engines: YF-24B assembly of single fixed YF-22B liquid hypergolic bipropellant, single start; and four gimbaled YF-23B verniers for steering
Length: 10.41 m
Diameter: 3.35 m
Dry mass: 4,000 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 35,500 kg
Thrust: 788.4 kN vac
Burn time: 126.8 s (verniers continue to burn for further 10 s)

CZ-4A STAGE 3
Designation: L-14
Engines: paired YF-40, gimbaled ±4.5o
Length: about 6.24 m
Diameter: 2.90 m
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant mass: 14,150 kg
Thrust: 98.1 kN vac
Burn time: 321 s (single burn?)
Attitude control: 14 hydrazine thrusters provide attitude control during coast and final orbit trim

CZ-4A FAIRING
Two fairing versions are available: A is 4.91 m long, 2.90 m diameter (envelope 2.91 x 2.36 m); B is 8.48 m long, 3.35 m diameter (envelope 6.50 x 3.00 m). The A-type can be fitted with a lower 1.95 m high cylindrical section for a secondary payload to be carried below. Piggyback payloads can be released from the forward support cone.


CZ-4B SPECIFICATIONS

First launch: 6-Sep-1988
Number launched: 2 to end-1995
Launch sites: Jiuquan and Taiyuan
Principal uses: medium-class payloads into Sun-synchronous polar orbits; typically meteorological and Earth observation satellites
Vehicle success rate: 100%
Performance:
LEO (200 km, 70o): 4,200 kg
Sun-synchronous (900 km, 99o): 2,800 kg (stage 3 restart); 1,650 kg (stage 3 single burn)
GTO (200 x 35,800 km, 28.5o): 1,500 kg
Number of stages: 3
Overall length: 41.895 m
Principal diameter: 3.35 m
Launch mass: 249,000 kg
Launch thrust: 2,961 kN sea level
Guidance: all inertial

CZ-4B STAGE 1
As CZ-4A.

CZ-4B STAGE 2
As CZ-4A.

CZ-4B STAGE 3
Designation: L-14?
Engines: paired uprated YF-40?
Length: about 6.24 m
Diameter: 2.90 m
Stage mass: 16,700 kg
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Thrust: 101.0 kN vac
Burn time: 412 s (single or dual burn)

CZ-4B FAIRING
As CZ-4A.



SLREC / YF-2A
Configuration: cluster of four chambers
Application: CZ-1 family stage 1, CSS-3 IRBM
First flown: Jun-1964?
Engine cycle: gas generator
Oxidizer: nitric acid
Fuel: UDMH
Propellant flow rate: 115 kg/s?
Thrust: 275.3 kN SL each chamber
Specific impulse: 241 s vac
Burn time: about 130 s operational

SLREC / YF-3
Application: CZ-1 family stage 2, CSS-3 IRBM
First flown: Jun-1964?
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant flow rate: 50 kg/s?
Thrust: 294.2 kN vac
Specific impulse: 287 s vac
Burn time: about 130 s operational

SLREC / YF-20/21 & YF-20B/21B
Configuration: four gimbaled YF-20s are clustered to create the YF-21 assembly for the L-140 stage 1 (four YF-20B to create YF-21B for L-180 stage 1). The LB-40 strap-ons each incorporate a single YF-20B
Application: CZ-2C/3 stage 1 for YF-20/21; CZ-2E/3B/3C strap-on for YF-20B; CZ-2D/2E/3A/3B/3C/4 for YF-21B
First flown: 5-Nov-1974 (YF-20/21)
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant flow rate: 270 kg/s?
Mixture ratio: 2.10 YF-20/21; 2.12 YF-20B/21B
Thrust: 696.2 kN SL for YF-20/21 of L-140 stage 1; 740.35 kN SL for YF-20B of LB-40 strap-on and Y-20B/21B of L-180 stage 1
Specific impulse: 259 s SL YF-20/21; 260.7 s SL YF-20B/21B
Burn time: 125-160 s operational

SLREC / YF-22/22B & YF-24/24B
Configuration: a single fixed YF-22 and four gimbaled YF-23 verniers, providing steering, create the Y-24 assembly for the L-35 stage 2 (single YF-22B and four YF-23B to create YF-24B for uprated L-35 and L-90 second stages)
Application: CZ-2C/3 stage 2 for YF-24; CZ-2D/2E/3A/3B/3C/4 stage 2 for YF-24B
First flown: 5-Nov-1974 (YF-22)
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant flow rate: 270 kg/s?
Mixture ratio: 2.18 YF-22/22B
Thrust: 719.8 kN vac for YF-22; 740.4 kN vac for YF-22B, but 845.3 kN attainable
Specific impulse: 289 s vac YF-22; 298 s vac YF-22B
Burn time: 300 s CZ-2E; 110 s others

SLREC / YF-23/23B
Configuration: four gimbaled YF-23/23Bs provide steering for the single fixed YF-22/22B on the L-35 and L-90 second stages (assembly designated YF-24/24B)
Application: as YF-22/22B
First flown: 5-Nov-1974 (YF-23)
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Propellant flow rate: 16 kg/s for all four chambers with single pump?
Mixture ratio: 1.57
Thrust: 46.1 kN vac for YF-23; 47.1 kN vac for YF-23B total (4 chambers)
Specific impulse: 281.7 s vac YF-23; 289 s vac YF-23B
Burn time: up to 300 s; 136 s for CZ-4

SLREC / YF-40
Configuration: paired gimbaled chambers
Application: L-14 stage 3 of CZ-4
First flown: 6-Sep-1988
Dry Mass: each 70 kg (83 kg for 4B)
Exit diameter: 0.63 m
Oxidizer: nitrogen tetroxide
Fuel: UDMH
Mixture ratio: 2.14
Thrust: 98.1 kN vac (103.0 kN vac 4B) for pair
Specific impulse: 305 s vac (303 s vac 4B)
Expansion ratio: 55:1
Combustion chamber pressure: 45.4 atm
Burn time: 321 s single burn (4B: 412 s single or dual burn)

CALT / YF-73
Application: H-8 stage 3 of CZ-3
First flown: 29-Jan-1987
Number flown: 9 to end-1995
Dry Mass: 236 kg
Length: 1.44 m
Maximum diameter: 2.22 m
Engine cycle: gas generator
Oxidizer: liquid oxygen, delivered at 9.09 kg/s
Fuel: liquid hydrogen, delivered at 1.82 kg/s
Mixture ratio: 5.0
Thrust: 44.15 kN vac total (4 chambers)
Specific impulse: 420 s vac
Expansion ratio: 40:1
Combustion chamber pressure: 26.0 atm
Burn time: two burns of 500 s + 300 s

CALT / YF-75
Application: H-18 stage 3 of CZ-3A/3B/3C
First flown: 8-Feb-1994
Number flown: 2 to end-1995
Oxidizer: liquid oxygen
Fuel: liquid hydrogen
Propellant flow rate: 19 kg/s each chamber?
Mixture ratio: 5.0
Thrust: 78.4 kN vac each chamber
Specific impulse: 442 s vac
Expansion ratio: 80:1
Combustion chamber pressure: 37.15 atm
Burn time: 470 s total, dual start


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