May 31, 2008, 5:45 GMT
Washington - Japanese astronaut Akihiko Hoshide was set to be among the crew of seven launching later Saturday on the shuttle Discovery, with good weather predicted.
Hoshide will help install the largest single module ever on the International Space Station - the long-awaited centrepiece of Japan's Kibo laboratory, named for 'hope' in Japanese.
When it blasts into orbit from Cape Canaveral, Florida, about 2102 GMT, Discovery will also be carrying the main part of Kibo, formally known as the Japanese Experiment Module (JEM).
It weighs 14,000 kilogrammes and spans 4.4-by-12.2 metres - an enormous object that will fill the cargo bay of the shuttle, NASA said.
Other parts of Kibo have already been installed or will be installed on the mission after the upcoming flight. This large capsule will house all the science work, including an area that is open to space for outdoor experiments.
Hoshide, Japan's Aerospace Exploration Agency astronaut, is to install the module and Kibo's robotic arm system.
'This is a big step for the Japanese community, the science community especially, because that means that they can start their own science,' he said.
NASA's weather officer Kathy Winters said Friday the weather looked promising for launch, with sea breezes clearing away coastal showers expected in the morning.
'After months of hard work and preparation, Discovery and its crew are ready to fly,' said NASA test director Jeff Spaulding during a morning briefing on Discovery's countdown status. 'All of our systems are in great shape, we're tracking no issues, and we're right on schedule for tomorrow's launch.'
Discovery also will deliver new station crew member Greg Chamitoff and bring back flight engineer Garrett Reisman, who will end a three- month stay aboard the outpost.
The mission, which will include three spacewalks, marks a halfway point to mothballing the US shuttle programme.
The mission will be the 10th shuttle flight since NASA returned to space in July 2005 after the 2003 Columbia disaster. After the upcoming mission, only 10 more shuttle flights are scheduled before the ageing spacecraft are mothballed for good in 2010.
NASA shuttles will fly another seven construction missions to the International Space Station, with another two missions held in reserve for delivering spare parts.
In September or October, the Atlantis shuttle is to head to the Hubble space telescope. The mission is complicated because a back-up shuttle must be on the launching pad as a precaution, if a rescue mission is needed.
The Hubble's vision has been fading as some of its systems need servicing, and NASA had intended to mothball the orbiting telescope before a replacement is launched in 2013.
But NASA relented after hefty protests from astronomers, who have been able to look back into space and time 2.2 billion light years because Hubble's view is not blurred by Earth's atmosphere.
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