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THE ISAS FAMILY
L-4S: (1966) First Japanese satellite launcher derived from L-3H sounding rocket.
M-4S: (1970) Orbital launcher based on L-4S technology.
M-3C: (1974) Based on M-4S.
M-3H: (1977) Based on M-3C but with uprated first stage.
M-3S: (1980) Based on M-3H.
M-3SII: (1985) Major uprating of M-3S.
M-5: (1997) New all-solid launcher with greatly increased payload performance.
First launch: 12-Feb-1997
Number launched 1 thru Feb-1997
Launch sites: Kagoshima
Vehicle success rate: 100%
LEO (200 km, 31o): 2,000 kg
LEO (500 km, 31o): 1,200 kg
Sun-synchronous: 800 kg
GTO: 800 kg
Escape: 520 kg Moon, 450 kg Mars/Venus (9.0 km2/s2)
Availability: launches are restricted to Jan-Feb/Aug-Sep windows imposed by the fishing lobby and range safety requirements
Cost: Y5.85 billion per mission
Number of stages: 3 + optional stage 4
Overall length: 31.2 m
Principal diameter: 2.50 m
Launch mass: 128,400 kg (excluding payload)
Guidance: active radio guidance with inertial using fiber optic gyros and microprocessor as backup on early flights. Inertial system may be used later. Other electronics, such as telemetry ranging and command systems transferred from M-3SII, are also in a bay at top of stage 3
M-5 STAGE 1
Length: 13.65 m
Diameter: 2.50 m
Mass at ignition: 82,500 kg
Propellant mass: 71,700 kg
Thrust: 4,119 kN SL average
Burn time: 47.1 s (effective)
Attitude control: movable nozzle, actuated by gas generator
M-5 STAGE 2
Stage 1 separates at 70 s and stage 2 ignites simultaneously (fire in the hole) to reduce gravity losses. The lattice structure of the 1,762 kg, 3.84 m high interstage vents the exhaust and the three 120o supporting panels are released by FLSC Flexible Linear Shaped Charges and pushed out by springs from top. Stage 2 incorporates an extending nozzle, increasing expansion ratio from 27.9 to 37.1.
Length: 6.71 m
Diameter: 2.51 m
Mass at ignition: 34,300 kg
Propellant mass: 31,100 kg
Thrust: 1,206 kN vac average
Burn time: 70.2 s (effective)
Attitude control: liquid injection TVC
M-5 STAGE 3
904 kg, 2.45 m high aluminum interstage. Extending nozzle saves 300 kg and 1 m length.
Length: 3.55 m
Diameter: 2.2 m
Mass at ignition: 11,100 kg
Propellant mass: 10,100 kg
Thrust: 289 kN vac average
Burn time: 103.5 s (effective)
Attitude control: movable nozzle (electrical actuation)
715 kg clamshell fairing of CRFP skins on honeycomb sandwich, length about 9 m, 2.50 m diameter. Outer surface covered by cork for thermal protection.