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H-ii adeos.gif
The launch of H-II Flight 4, carrying ADEOS I
Function Launch vehicle
Manufacturer Mitsubishi Heavy Industries
Country of origin Japan
Height 49 m (160 ft)
Diameter 4 m (13.1 ft)
Mass 260,000 kg (570,000 lb)
Stages 2
Payload to LEO 10,060 kg (22,170 lb)
Payload to
3,930 kg (8,660 lb)
Launch history
Status Retired
Launch sites LC-Y, Tanegashima
Total launches 7
Successes 5
Failures 1
Partial failures 1
First flight 3 February 1994
Last flight 15 November 1999
No. boosters 2
Engines 1 Solid
Thrust 1,539.997 kN
Specific impulse 273 sec
Burn time 94 seconds
Fuel Solid
First stage
Engines 1 LE-7
Thrust 1,077.996 kN (242,343 lbf)
Specific impulse 446 sec
Burn time 346 seconds
Fuel LOX/LH2
Second stage
Engines 1 LE-5A
Thrust 121.5 kN (27,313 lbf)
Specific impulse 452 sec
Burn time 600 seconds
Fuel LOX/LH2

The H-II (H2) rocket was a Japanese satellite launch system, which flew seven times between 1994 and 1999, with five successes. It was developed by NASDA in order to give Japan a capability to launch larger satellites in the 1990s.[1] It was the first two-stage liquid-fuelled rocket Japan made using only technologies developed domestically.[2] It was superseded by the H-IIA rocket following reliability and cost issues.


Prior to H-II, NASDA had to use components licensed by the United States in its rockets. In particular, crucial technologies of the H-I and its predecessors were from the Delta rockets. The H-I did have domestically produced components, such as the LE-5 engine on the second stage and the inertial guidance system. H-II added to this by domestically developing the LE-7 liquid-fuel engine of the first stage and the solid booster rockets.

The H-II was developed under the following policies, according to a NASDA press release:[1]

  1. Develop the launch vehicle with Japanese space technology.
  2. Reduce both development period and costs by utilizing developed technologies as much as possible.
  3. Develop a vehicle which can be launched from the existing Tanegashima Space Center.
  4. Use design criteria which allows sufficient performance for both the main systems and subsystems. Ensure that development will be carried out properly, and safety is taken into account.


Development of the LE-7 engine which started in 1984 was not without hardships, and a worker died in an accidental explosion. The first engine was completed in 1994, two years behind the original schedule. In 1990, Rocket System Corporation was established to operate the launch missions after the rockets' completion.

In 1994, NASDA succeeded in launching the first H-II rocket, and succeeded in five launches by 1997. However, each launch cost 19 billion yen (190 million USD), too expensive compared to international competitors like Ariane. (This is in part due to the changes in exchange rates, which was 240 yen to a dollar when the project planning started in 1982, but had changed to 100 yen a dollar by 1994.) Development of the next-generation H-IIA rockets started in order to minimize launch costs.

The successive failure of flight 5 in 1998 and flight 8 in the following year brought an end to the H-II series. To investigate the cause of the failure and to direct resources into the H-IIA, NASDA cancelled flight 7 (which was to be launched after F8 due to changes in schedule), and terminated the H-II series.[2]

H-II flights

Flight Date (UTC) Payload nickname Payload Orbit Result
TF1 (Test Flight) February 3, 1994
Ryūsei OREX (Orbital Re-entry Experiment) LEO Success
Myōjō VEP (Vehicle Evaluation Payload) GTO
TF2 August 28, 1994
Kiku 6 ETS-VI (Engineering Test Satellite-VI) GEO Success
TF3 March 18, 1995
Himawari 5 GMS-5 (Geostationary Meteorological Satellite-5) GEO Success
SFU (Space Flyer Unit) LEO
F4 August 17, 1996
Midori ADEOS (Advanced Earth Observing Satellite) LEO Success
Fuji 3 Fuji OSCAR 29, JAS-2 LEO
F6 November 27, 1997
TRMM (Tropical Rainfall Measuring Mission) LEO Success
Kiku 7 (Orihime & Hikoboshi) ETS-VII (Engineering Test Satellite-VII) LEO
F5 February 21, 1998
Kakehashi COMETS (Communications and Broadcasting Engineering Test Satellites) GEO Partial failurenote 1
F8 November 15, 1999
MTSAT (Multi-functional Transport Satellite) GEO Failurenote 2
F7 Canceled
(planned 2001)
Kodama DRTS (Data Relay Test Satellite) GTO Canceled
Tsubasa MDS-1 (Mission Demonstration Satellite-1) GTO

note 1. ^ Faulty brazing in second-stage engine cooling system caused engine burn through and cable damage resulting in shutdown midway through the upper stage's second burn, leaving spacecraft in elliptical LEO instead of GTO. Spacecraft thrusters raised orbit enough to complete some communications experiments.

note 2. ^ Cavitation in the first stage hydrogen turbopump impeller caused an impeller blade to fracture, resulting in loss of fuel and rapid shutdown of the engine at T+239 s. The vehicle impacted the ocean 380 km NW of Chichi-jima.


See also


  1. 1.0 1.1 "H-II Launch Vehicle No.4" (Press release). NASDA. Retrieved 2007-06-25.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  2. 2.0 2.1 JAXA. "H-II Launch Vehicle". Launch Vehicles and Space Transportation Systems. JAXA Website. Retrieved 2007-06-25.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>

External links