Too costly

When the development of the H-2 started in the mid-1980s, operating cost had been secondary to the technical challenge. As they were now in a recession, the Japanese realised that their heavy launcher was so costly to operate that it was uncompetitive commercially, which meant that there was no prospect of generating revenues to offset the investment.170,m This led to the development of the H-2A, which was to be cheaper to manufacture and to operate. The first stage was to have the LE-7A with a thrust of 110,000 kilograms rather than 100,000 kilograms, and use shorter, fatter Nissan solid strap-ons giving a thrust of 175,000 kilograms.172 The LE-5B of the second stage would have a thrust of 14,000 kilograms rather than 12,500 kilograms.173,17V75 Different combinations of strap-on motors would cater for a range of pay-loads.176 The basic vehicle with two solid rockets would be able to insert 4 tonnes into geosynchronous transfer orbit, or 2.2 tonnes directly into geostationary orbit - an improvement of 200 kilograms over the H-2. The auxiliary strap-ons were bought by Mitsubishi from the Thiokol Corporation, which had stretched its Castor IVA to improve the performance by 30 per cent.177 Adding two auxiliaries would increase the capacity to geosynchronous transfer orbit to 4.25 tonnes, and four would raise it to 4.5 tonnes.178 With a fee of $80 million, the H-2A would be able to compete against the Ariane 4 and Atlas II for satellites in the HS-601 class. The Mitsubishi-led Rocket Systems Corporation readily sold 10 launches to Hughes Space and Com

A cutaway of the H-2, the second such vehicle being prepared with the ETS-6 satellite, and an artist's impression of the COMETS satellite.

munications which, acting on behalf of its customers, was spreading its satellites around the different launch vehicles.

The liquid hydrogen turbopump of an LE-7 engine.
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