H-IIB

H-IIB
H-IIB Flight 8 at the launch pad in September 2019
FunctionMedium-lift launch vehicle
ManufacturerMitsubishi Heavy Industries
Country of originJapan
Cost per launchUS$112.5 million
Size
Height56.6 m (185 ft 8 in)
Mass531,000 kg (1,171,000 lb)
Stages2
Capacity
Payload to LEO
Mass19,000 kg (42,000 lb)
Payload to ISS (carrying the HTV)
Mass16,500 kg (36,400 lb)
Payload to GTO
Mass8,000 kg (18,000 lb)
Associated rockets
FamilyH-II family
Based onH-IIA
Derivative workH3
Comparable
Launch history
StatusRetired
Launch sitesTanegashima, LA-Y2
Total launches9
Success(es)9
First flight10 September 2009
Last flight20 May 2020
Carries passengers or cargoH-II Transfer Vehicle
Boosters – SRB-A3
No. boosters4
Height15.1 m (49 ft 6 in)
Diameter2.5 m (8 ft 2 in)
Gross mass76,500 kg (168,700 lb) each
Propellant mass66,000 kg (146,000 lb) each
Maximum thrust2,305 kN (518,000 lbf) each
Total thrust9,220 kN (2,070,000 lbf)
Specific impulse283.6 s (2.781 km/s)
Burn time116 seconds
PropellantHTPB
First stage
Height38 m (124 ft 8 in)
Diameter5.2 m (17 ft 1 in)
Gross mass202,000 kg (445,000 lb)
Propellant mass177,800 kg (392,000 lb)
Powered by2 × LE-7A
Maximum thrust2,196 kN (494,000 lbf)
Specific impulse440 seconds (4.3 km/s)
Burn time352 seconds
PropellantLH2 / LOX
Second stage
Height11 m (36 ft 1 in)
Diameter4 m (13 ft 1 in)
Gross mass20,000 kg (44,000 lb)
Propellant mass16,600 kg (36,600 lb)
Powered by1 × LE-5B
Maximum thrust137 kN (31,000 lbf)
Specific impulse448 s (4.39 km/s)
Burn time499 seconds
PropellantLH2 / LOX

The H-IIB (H2B) was a Japanese expendable launch system jointly developed by JAXA and Mitsubishi Heavy Industries. It was used exclusively to launch the H-II Transfer Vehicle (HTV, or Kōnotori) cargo spacecraft to the International Space Station.

The H-IIB was a two-stage rocket powered by liquid hydrogen and liquid oxygen (hydrolox) engines, with four strap-on solid rocket boosters, and was launched from the Tanegashima Space Center in southern Japan. It could deliver up to 8,000 kg (18,000 lb) to geostationary transfer orbit (GTO), compared with 4,000–6,000 kg (8,800–13,200 lb) for its predecessor, the H-IIA. Its performance to low Earth orbit (LEO) was sufficient to carry the 16,500 kg (36,400 lb) HTV.

The H-IIB made its debut in September 2009 and flew nine times through May 2020, all successfully.