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In happier times: a Japanese H-II rocket blasts off successfully from Tanegashima Space Centre. Credit: NASDA

The strategy of Japan's National Space Development Agency (NASDA) needs to be overhauled after the failure of three space missions in nine months, says Sadakazu Tanigaki, director-general of the Science and Technology Agency.

The space agency came under fire at a meeting held by Japan's Space Activities Commission over NASDA's slow investigation of the recent failure of an H-II rocket launch. The launcher, carrying the world's largest telecommunications satellites, failed to reach geostationary orbit after an engine failure (see Nature 391, 832; 1998).

The failure came as a severe shock to NASDA, whose two previous missions, the Advanced Earth Observation Satellite and the Advanced Land Observation Satellite, also ended in failure (see Nature 388, 105; 1997). An investigation has revealed an abnormality in the combustion chamber of H-II's second-stage LE5A engine, manufactured by Mitsubishi Heavy Industries. But the precise cause of the failure is still unknown.

Toshihiko Fujita of NASDA, who is responsible for the investigation, suggests the construction chamber may not have been strong enough. But he says it is unlikely there was a flaw in its design, pointing out that NASDA's past 30 medium-sized and large rockets have all been launched successfully.

Part of the problem appears to lie in the failure of NASDA to communicate adequately with the contractor who built the engines. Although the agency has a scheme to send its engineers to contractor companies, only one engineer has gone so far.

Although the immediate concern is to find the cause of the engine failure, others fear that the prolonged investigation may deter Japan from entering the international commercial satellite business.

Rocket System, a commercial satellite-launching company collaborating with more than 70 space-related companies, has signed a contract with Hughes Space and Communication International (HSCI) and Space Systems/Loral to launch more than 20 satellites using a new H-II launch vehicle. The total cost of the operation, planned to happen between 2000 and 2007, is thought to be about ¥200 billion (US$1.5 billion).

The two US commercial satellite manufacturers have so far shown little concern about the failure of H-II. Robert Berry, president of Space Systems/Loral, says “failures are indispensable to space development”.

Although all H-II rockets have previously been developed indigenously, the new H-IIA will, as part of NASDA cost-cutting, be built using imported materials and subsystems. This is expected to reduce the cost from ¥18 billion per launch to less than ¥8.5 billion. “Now that Japan has an established technology for rocket development, the next step is to minimize the cost to enter global competition,” says Hiroshi Imamura, director of Rocket System.

Imamura says inspection can be automated, and the construction of the rockets, which normally takes three years, can be reduced to two. The ultimate goal, he says, is to mass-produce rockets to launch them more frequently — only one H-II is, at present, launched each year in Japan.

With just two-and-a-half years left until Japan joins the international commercial satellite business, Imamura suggests that mass production of rockets could help improve mechanical reliability. “Since we only build one or two rockets each year, it is difficult for us to predict reliability, and increased production could help us improve our technology,” he says.