The H–I or H–1 was a Japanese liquid-fuelled

carrier rocket A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and syste ...

, consisting of a licence-produced American first stage and set of

booster rocket A booster rocket (or engine) is either the first stage of a multistage launch vehicle, or else a shorter-burning rocket used in parallel with longer-burning sustainer rockets to augment the space vehicle's takeoff thrust and payload capabil ...

s, and all-Japanese upper stages. The H in the name represented the use of liquid hydrogen fuel in the second stage. It was launched nine times between 1986 and 1992. It replaced the N-II, and was subsequently replaced by the H-II, which used the same upper stages with a Japanese first stage. The first stage of the H–I was a licence-built version of the Thor-ELT, which was originally constructed for the US

Delta 1000 The Delta 1000 series (also referred to as Straight-Eight) was an American expendable launch system which was used to conduct eight orbital launches between 1972 and 1975. It was a member of the Delta family of rockets. Several variants existed, d ...

rocket. The stage had already been produced under licence in Japan for the N-I and N-II rockets. The second stage was entirely Japanese, using an LE-5 engine, the first rocket engine in Japan to use a

cryogenic fuel Cryogenic fuels are fuels that require storage at extremely low temperatures in order to maintain them in a liquid state. These fuels are used in machinery that operates in space (e.g. rockets and satellites) where ordinary fuel cannot be used, d ...

. On launches to

Geosynchronous transfer orbit A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step f ...

s, a

Nissan , trading as Nissan Motor Corporation and often shortened to Nissan, is a Japanese multinational automobile manufacturer headquartered in Nishi-ku, Yokohama, Japan. The company sells its vehicles under the Nissan, Infiniti, and Datsun bra ...

–built UM-69A solid motor was used as a third stage. Depending on the mass of the payload, either six or nine US Castor 2 SRMs were used as

Launch history

When the H–1 was announced in 1986, company representative Tsuguo Tatakawe clarified that it would only be used to launch indigenous (i.e. Japanese) payloads, that only two launches per year could be mounted, and that the launch window consisted of a four-month period in which Japanese fishing fleets were not active (the falling launch boosters may damage fishing nets in the ocean waters).''Japan's H–1 and H–2 rockets'',

Air & Space/Smithsonian ''Air & Space/Smithsonian'' is a quarterly magazine published by the National Air and Space Museum The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the ...

, February/March 1987, p. 19

References

* * * Mitsubishi Heavy Industries space launch vehicles Vehicles introduced in 1986 Thor (rocket family) Japan–United States relations {{rocket-stub

Launch history

See also

References