Space Transportation Systems H-II Launch Vehicle

Operation Finished

About H-II Launch Vehicle

The H-II launch vehicle, the central rocket in Japan's space program, with the capability to launch a two-ton class satellite into geostationary orbit, is a two-stage rocket that was developed with Japanese independent technology in all stages. In addition to geostationary satellite, it can also be used to launch payloads into low and medium-altitude orbits. For greater economy, it is possible to launch simultaneously two geostationary satellites weighing about one ton each.
The 1st stage has a large, high-performance liquid oxygen/liquid hydrogen engine known as the LE-7. Newly developed for the H-II launch vehicle, it offers propulsion of approximately 110 tons in a vacuum. The 2nd stage uses the LE-5A engine. This reignitable engine offers higher performance and reliability than the LE-5 engine developed for the H-I launch vehicle. The guidance system employs an inertial guidance method, a further improvement on H-I development results.
The H-II launch vehicle, since the first successful launch in 1994, was utilized in a total of 7 launches. Due to launch failure of the vehicle No.8 in 1999 came next to unsuccessful injection of the satellite by the No.5 in 1998, scheduled launch of the No.7 was cancelled, but the technology used in developing the H-II will be exploited for developing H-IIA.

Major characteristics


Principal Specifications

Overall length 50m
Diameter 4m
Total weight 260.0t (not including payload weight)
Guidance syst Strapped-down inertial guidance system

First Stage

The first stage of the H-II launch vehicle consists of the first stage core vehicle equipped with the LE-7 engine and two solid rocket boosters(SRBs) . The LE-7 engine is a liquid hydrogen/liquid oxygen engine with 86 tons of thrust(at sea level) . The SRBs are polybutadiene composite solid propellant boosters with 158 tons of thrust each(at sea level) . The guidance and control of the first stage is performed by the hydraulically steerable nozzles of the LE-7 engine and of the SRBs controlled by the Inertial Guidance Computer(IGC). Two auxiliary engines are also provided to control attitude.

Second Stage

The second stage of the H-II launch vehicle is equipped with the LE-5A Iiquid hydrogen/liquid oxygen engine. The LE-5A engine is an improved LE-5 engine(developed for the second stage of the H - I launch vehicle) and provides 12 tons of thrust (in vaccum). The guidance and control of the second stage is performed by the hydraulically steerable nozzle of the LE-5A engine and the reaction control system controlled by the IGC.

Guidance and Control System

The H-II launch vehicle employs a strapped-down inertial guidance and control system. The system consists of the Inertial Measurement Unit(lMU) which uses three ring laser gyros and the IGC. The inertial guidance and control system enables the H-Il launch vehicle to correct errors automatically and to maintain the planned orbit without commands from the ground station.

Payload Fairing

The payload fairing protects the payload from the severe launch environment and from contamination on the ground.

Flight Sequence

Launch Records

Flight No. Launch Date Peyload
TR-I-1 9/6/1988 The acquisition of the technical data for development of a H-II rocket
TR-I-2 1/27/1989
TR-I-3 8/20/1989
1F 2/4/1994 Orbital Re-entry Experiment (OREX)
H-II Launch Vehicle Evaluation Payload "Myojo"(VEP)
2F 8/28/1994 Engineering Test Satellite VI "KIKU-6"(ETS-VI)
3F 3/18/1995 Space Flyer Unit (SFU)
Geostationary Meteorological Satellite-5 "Himawari-5"(GMS-5)
4F 8/17/1996 Advanced Earth Observing Satellite "Midori"(ADEOS)
Japan Amateur Satellite-3 "FUJI-3"(JAS-2)
6F 11/28/1997 Tropical Rainfall Measuring Mission "TRMM"
Engineering Test Satellite VII "KIKU-7"(ETS-VII)
7F 2/21/1998 Communications and Broadcasting Engineering Test Satellites "Kakehashi"(COMETS)
8F 11/15/1999 Multi-functional Transport Satellite (MTSAT)
* Destruct Command was sent as the vehicle went out of the planned flight path.