Prior to H-II, NASDA had to use components licensed by the United States in its rockets. In particular, crucial technologies of H-I and its predecessors were from the Delta rockets (the manufacturer of the Delta rockets, McDonnell Douglas, later Boeing and the United Launch Alliance, would later use the H-IIA's technologies (the rocket itself is the successor to the H-II) to create the Delta III, albeit short lived). Although the H-I did have some domestically produced components, such as LE-5 engine on the second stage and inertial guidance system, the most crucial part, the first stage engine, was a licence-built version of the Thor-ELT of the US. By developing the LE-7 liquid-fuel engine and the solid booster rockets for the first stage, all stages of H-II had become "domestically developed".
The H-II was developed under the following policies, according to a NASDA press release:3
The H-II was new, incorporating larger LH2/LOX tanks, and a new upper stage, consisting of a cylindrical LH2 tank with a capsule-shaped LOX tank. The LH2 tank cylinder carried payload launch loads, while the LOX tank and engine were suspended below within the rocket's inter-stage. The second stage was powered by a single LE-5A engine.4
Development of the LE-7 engine which started in 1984 was not without hardships, and a worker died in an accidental explosion. The first engine was completed in 1994, two years behind the original schedule. The Rocket Systems Corporation (RSC), a consortium of 74 companies including Mitsubishi Heavy Industries, Nissan Motors, and NEC, was established in 1990 to manage launch operations after the rockets' completion. In 1992, it had 33 employees.5
In 1994, NASDA succeeded in launching the first H-II rocket, and succeeded in five launches by 1997. However, each launch cost 19 billion yen (US$190 million), too expensive compared to international competitors like Ariane. (This is in part due to the Plaza Accord's changes to the exchange rate, which was 240 yen to a dollar when the project planning started in 1982, but had changed to 100 yen a dollar by 1994.) Development of the next-generation H-IIA rockets started in order to minimize launch costs.
In 1996, RSC signed a contract with the Hughes Space and Communications Group to launch 10 satellites. The successive failure of flight 5 in 1998 and flight 8 in the following year brought an end to the H-II series and the contract with Hughes.6 To investigate the cause of the failure and to direct resources into the H-IIA, NASDA cancelled flight 7 (which was to be launched after F8 due to changes in schedule), and terminated the H-II series.7
Main article: List of H-II series and H3 launches
"H-II Launch Vehicle No.4" (Press release). NASDA. Archived from the original on 11 December 2003. Retrieved 2007-06-25. https://web.archive.org/web/20031211190020/http://www.nasda.go.jp/pr/services/presskit/h2-f4/h2index_e.html ↩
JAXA. "H-II Launch Vehicle". Launch Vehicles and Space Transportation Systems. JAXA Website. Archived from the original on 2013-10-30. Retrieved 2007-06-25. https://web.archive.org/web/20131030155512/http://www.jaxa.jp/projects/rockets/h2/index_e.html ↩
"About H-II Launch Vehicle". JAXA. Retrieved 12 December 2022. https://global.jaxa.jp/projects/rockets/h2/index.html ↩
Helm, Leslie (1992-07-13). "Japan Discovers It's Harder to Be a Star in Space : Aerospace: The failure of a new rocket sets back its effort to become a key player in the commercial launch business". Los Angeles Times. Retrieved 2021-05-19. https://www.latimes.com/archives/la-xpm-1992-07-13-fi-3846-story.html ↩
"Hughes cancels NASDA rocket deal". The Japan Times. 2000-05-26. Retrieved 2021-05-14. https://www.japantimes.co.jp/news/2000/05/26/national/hughes-cancels-nasda-rocket-deal/ ↩