The launch of H-II Flight 4, carrying ADEOS I
|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)|
|Payload to LEO||10,060 kg (22,170 lb)|
|3,930 kg (8,660 lb)|
|Launch sites||LC-Y, Tanegashima|
|First flight||3 February 1994|
|Last flight||15 November 1999|
|Boosters (Stage 0)|
|Specific impulse||273 sec|
|Burn time||94 seconds|
|Thrust||1,077.996 kN (242,343 lbf)|
|Specific impulse||446 sec|
|Burn time||346 seconds|
|Thrust||121.5 kN (27,313 lbf)|
|Specific impulse||452 sec|
|Burn time||600 seconds|
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. It was the first two-stage liquid-fuelled rocket Japan made using only technologies developed domestically. It was superseded by the H-IIA rocket following reliability and cost issues.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:
- Develop the launch vehicle with Japanese space technology.
- Reduce both development period and costs by utilizing developed technologies as much as possible.
- Develop a vehicle which can be launched from the existing Tanegashima Space Center.
- 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.
 H-II flights
|TF1 (Test Flight)||February 4, 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||Midori II||ADEOS-II (Advanced Earth Observing Satellite II)||Canceled|
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.
The Ground Test Vehicle of H-II, now installed at Tsukuba Space Center.
The first and second stages of the canceled Flight 7, at a hangar in Tanegashima Space Center.
 See also
- H-II Orbiting Plane (HOPE)
- H-II Transfer Vehicle (HTV)
- H-II (rocket family)
- Comparison of orbital launchers families
- Comparison of orbital launch systems
|Wikimedia Commons has media related to: H-II launch vehicles|
- H-II Launch Vehicle, JAXA.