HISTORY OF LIQUID PROPELLANT ROCKETS IN JAPAN

摘要

Liquid propellant vehicles have been developed to launch Japanese satellites by NASDA. 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 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 and third stage were used 100% Japanese components. The second stage burned liquid oxygen and liquid hydrogen. H- I was employed on geostationary orbit (GEO) missions to place a payload (up to 1,100kg) into geo geosynchronous transfer orbit (GTO). The H- I program concluded in 1992 with nine successes and zero failures.rnTo provide greater payload capacity and to permit an unencumbered vehicle based on all-Japanese propulsion systems, the H- II was developed. The H- II can lift payloads four times heavier than the H- I into Low Earth orbit (LEO) and GTO and will open the door for NASDA to explore the Moon and planets. The first mission, in 1994, deployed one experimental reentry satellite into LEO and one engineering test satellite into GTO. The H- IIA program was 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 costs and enhancing launch capability. The first flight of H- II A was in 2001.