H-II

H-II

H-II rocket at Tsukuba science museum & planetarium
Function
Project cost
Cost per launch
Cost per year
Size
Stages
Capacity
Payload to LEO
Altitude
	Template:Cvt
Volume
Payload to GTO
Altitude
	Template:Cvt
Volume
Associated rockets
Family
Comparable	Ariane 4, LVM3
Launch history
Status
Launch sites
Total launches
Success(es)
FailureTemplate:Pluralize from text
Partial failureTemplate:Pluralize from text
Notable outcomeTemplate:Pluralize from text
Landings
First flight
Last flight
Boosters
No. boosters	2
Empty mass
Gross mass
Propellant mass
Specific impulse
Burn time
Propellant
First stage
Empty mass
Gross mass
Propellant mass
Specific impulse
Burn time
Propellant
Second stage
Empty mass
Gross mass
Propellant mass
Specific impulse
Burn time
Propellant
Template:Edit on Wikidata

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 It was superseded by the H-IIA rocket following reliability and cost issues.

Background

Prior to H-II, NASDA had to use components licensed by the United States in its rockets. In particular, crucial technologies of H-I and its predecessors were from the Delta rockets (the manufacturer of the Delta rockets, McDonnell Douglas, later Boeing and the United Launch Alliance, would later use the H-IIA's technologies (the rocket itself is the successor to the H-II) to create the Delta III, albeit short lived). Although the H-I did have some domestically produced components, such as LE-5 engine on the second stage and inertial guidance system, the most crucial part, the first stage engine, was a licence-built version of the Thor-ELT of the US. By developing the LE-7 liquid-fuel engine and the solid booster rockets for the first stage, all stages of H-II had become "domestically developed".

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

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.

The H-II was new, incorporating larger LH₂/LOX tanks, and a new upper stage, consisting of a cylindrical LH₂ tank with a capsule-shaped LOX tank. The LH₂ tank cylinder carried payload launch loads, while the LOX tank and engine were suspended below within the rocket's inter-stage. The second stage was powered by a single LE-5A engine.

History

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. The Rocket Systems Corporation (RSC), a consortium of 74 companies including Mitsubishi Heavy Industries, Nissan Motors, and NEC, was established in 1990 to manage launch operations after the rockets' completion. In 1992, it had 33 employees.

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 (US$190 million), too expensive compared to international competitors like Ariane. (This is in part due to the Plaza Accord's changes to the exchange rate, 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.

In 1996, RSC signed a contract with the Hughes Space and Communications Group to launch 10 satellites. The successive failure of flight 5 in 1998 and flight 8 in the following year brought an end to the H-II series and the contract with Hughes. 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.

Launch history

Flight	Date (UTC)	Launch site	Payload	Orbit	Outcome
TF1	3 February 1994 22:20	Tanegashima, LA‑Y1	OREX, VEP	LEO / GTO	Template:Success
	First flight of the H-II launch vehicle. Launched OREX (Orbital Re-entry Experiment, nicknamed Ryūsei) and VEP-1 (Vehicle Evaluation Payload 1, nicknamed Myōjō)
TF2	28 August 1994 07:50	Tanegashima, LA‑Y1	ETS-VI	GEO	Template:Success
	Launched ETS-VI (Engineering Test Satellite VI, nicknamed Kiku-6)
TF3	18 March 1995 08:01	Tanegashima, LA‑Y1	GMS-5, SFU	GEO / LEO	Template:Success
	Launched GMS-5 (Geostationary Meteorological Satellite-5, nicknamed Himawari 5) and SFU (Space Flyer Unit)
F4	17 August 1996 01:53	Tanegashima, LA‑Y1	ADEOS I, Fuji OSCAR 29, JAS-2	LEO	Template:Success
	Launched ADEOS I (Advanced Earth Observing Satellite I, nicknamed Midori), Fuji OSCAR 29 and JAS-2
F6	November 27, 1997 21:27	Tanegashima, LA‑Y1	TRMM, ETS-VII	LEO	Template:Success
	Launched TRMM (Tropical Rainfall Measuring Mission) and ETS-VII (Engineering Test Satellite VII, nicknamed Kiku-7)
F5	February 21, 1998 07:55	Tanegashima, LA‑Y1	COMETS	GEO	Template:Partial failure
	Launched COMETS (Communications and Broadcasting Engineering Test Satellites, nicknamed Kakehashi). 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.
F8	November 15, 1999 07:29	Tanegashima, LA‑Y1	MTSAT	GEO	Failure
	Launched MTSAT (Multi-Functional Transport Satellite). 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 Chichijima.

Gallery

• 
  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)
  • H-IIA
  • H-IIB
• Comparison of orbital launchers families
• Comparison of orbital launch systems

External links

• H-II Launch Vehicle , JAXA.