History of Liquid Propellant Rockets in Japan

Paper number

IAC-05-E4.4.05

Author

Mr. Yoji Shibato, Japan Aerospace Exploration Agency (JAXA), Japan

Year

2005

Abstract

Program of launching Japanese satellites for space technology and applications purposes using liquid-propellant vehicles. The original N-series (N-I and N-II) launch vehicles were developed under license from the US and were closely related to the Delta launchers. Flown during 1975-1987, the N-series was replaced by the H-I launch vehicle (first flight in 1986), a hybrid US-Japanese design. The first stage of the H-I was essentially the same as that of the N-II with a liquid oxygen/kerosene main engine and 6-9 small solid-propellant strap-on boosters. The second stage and third stage were of Japanese origin.  The second stage burned liquid oxygen and liquid hydrogen. H-I was employed on GEO missions to place the payload (up to 1,100kg) in to GTO. The H-I program concluded in 1992 with nine successes and no failures.
To provide greater payload capacity and to permit unencumbered commercial space transportation offerings (the Delta licensing agreement restricted the use of the H-I for commercial flights), Japan developed the H-II launch vehicle based on all-Japanese propulsion systems. The H-II can lift payloads four times heavier than the H-I into LEO (up to 10 metric tons) and GTO (up to 4 metric tons) and will open the door to NASDA spacecraft designed to explore the Moon and planets. The first mission in 1994 deployed one payload into LEO and then carried an experimental package VEP (Vehicle Evaluation Payload) to GTO.
The H-II consists of a 2-stage core vehicle, burning liquid oxygen and liquid hydrogen in both stages, with two large solid-propellant strap-on boosters. The LE-7 first-stage main engine overcame numerous developmental difficulties, while the LE-5A engine used by the second stage merely represents an upgraded version of the proven LE-5 flown on the second stage of the H-I.
 The H-IIA program has started to meet diversifying launch demands in the beginning of the 21st century. Using expertise and know-how acquired through the development and operations of the H-II launch vehicle, the H-IIA launch vehicle was developed with the objectives of reducing launch cost and enhancing launch capability.  The first flight of H-IIA was in 2001.

Abstract document

IAC-05-E4.4.05.pdf

Manuscript document

IAC-05-E4.4.05.pdf (🔒 authorized access only).

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