N-II (rocket)

The N-II rocket
FunctionCarrier rocket
ManufacturerMcDonnell Douglas (design)
Mitsubishi Heavy Industries (production)
Country of originUnited States (design)
Japan (production)
Size
Height35 metres (115 ft)
Diameter2.44 metres (8.0 ft)
Mass132,690 kilograms (292,530 lb)
Stages2 or 3
Capacity
Payload to LEO
Mass2,000 kilograms (4,400 lb)
Payload to GTO
Mass730 kilograms (1,610 lb)
Associated rockets
FamilyDelta
Launch history
StatusRetired
Launch sitesTanegashima, Osaki
Total launches8
Success(es)8
First flight11 February 1981
Last flight19 February 1987
Boosters – Castor 2
No. boosters9
Powered by1 TX-354-3
Maximum thrust258.9 kilonewtons (58,200 lbf)
Specific impulse262 sec
Burn time37 seconds
PropellantSolid
First stage – Thor-ELT
Powered by1 MB-3-3
Maximum thrust866.7 kilonewtons (194,800 lbf)
Specific impulse290 sec
Burn time270 seconds
PropellantRP-1/LOX
Second stage – Delta-F
Powered by1 AJ-10-118F
Maximum thrust41.3 kilonewtons (9,300 lbf)
Specific impulse280 sec
Burn time335 seconds
PropellantHNO3/UDMH
Third stage (optional) – Star-37E
Powered by1 solid
Maximum thrust68 kilonewtons (15,000 lbf)
Specific impulse284 sec
Burn time42 seconds
PropellantSolid
Third stage (alternative, optional) – Burner-2
Powered by1 solid
Maximum thrust43.6 kilonewtons (9,800 lbf)
Specific impulse285 sec
Burn time42 seconds
PropellantSolid

The N-II or N-2 was a derivative of the American Delta rocket, produced under licence in Japan. It replaced the N-I-rocket in Japanese use. It used a Thor-ELT first stage, a Delta-F second stage, nine Castor SRMs, and on most flights either a Star-37E or Burner-2 upper stage, identical to the US Delta 0100 series configurations. Eight were launched between 1981 and 1987, before it was replaced by the H-I, which featured Japanese-produced upper stages. All eight launches were successful.