Abstract
The first flight of H-I launch vehicle was performed successfully on August 13 (1986). Her second stage was powered by the cryogenic engine LE-5 driven by turbopump systems, developed in Japan, for the first time. Later, requirement for turbopump’s flow-rate was increased as 40% to apply for the next generation launch vehicle, but fundamental turbopump configuration was not changed. In 19 flights data of LE-5s (including derivatives), no trouble caused by turbopumps is recorded. This paper reports research and development aspects of the turbopump systems of the LE-5 engine family.
