Cargo spaceship HTV, meets the ISS catcher in the sky

If the first launch of Japan's new heavy-lifting rocket passes without incident this month, the residents of the International Space Station will soon be taking delivery of food, water, some spanking new laptops, a robot arm and a couple of Earth-observing experiments.

Business as usual, you might think, except that the way this particular cargo gets to its destination is subtly different to its predecessors.

The reason? The cargo is being carried by the latest uncrewed spacecraft to vie for a place in the emerging market to supply the ISS. The driving force behind this latest space race is the impending retirement of NASA's space shuttle fleet, sometime in 2010.

This latest vehicle is the work of the Japan Aerospace Exploration Agency. JAXA's H-II Transfer Vehicle, or HTV, offers the space station a range of new capabilities.

First flight nerves
HTV is scheduled for lift-off sometime between 10 September and the end of the month, on board the HII-B launch vehicle, which has never flown before – and the record of successful first rocket launches is poor. For instance, the giant Ariane 5, which carries ESA's ATV, failed to launch several times before the glitches in the technology were finally ironed out.

A variant of JAXA's workhorse HII-A rocket, the HII-B has four solid rocket boosters instead of the HII-A's two – and has two main liquid-fuelled engines instead of the HII-A's one.

"This is indeed the HII-B's first launch. But many of the components are already working well on the HII-A," says Miyake. "We have great confidence in it."