H-II

The H-II was a two-stage Japanese satellite launch rocket that flew seven times between 1994 and 1999, with five successful flights. The National Space Development Agency of Japan, NASDA, developed it to give the country a way to put larger satellites into orbit in the 1990s. Its importance is that it was the first liquid-fuelled rocket Japan built using only home-grown technology: earlier vehicles such as the H-I leaned on licensed American designs, including a first stage engine derived from the US Thor. The H-II instead combined the new LE-7 first stage engine, two large solid boosters, and an upper stage powered by a single LE-5A engine, with liquid hydrogen and liquid oxygen tanks. It launched from the Tanegashima Space Center. Each launch cost about 19 billion yen, which made it uncompetitive against rivals such as Ariane, and failures on flights 5 and 8 ended the series and a satellite contract with Hughes. The H-IIA, a redesigned and cheaper successor, replaced it.