Tight squeeze ahead on space station

Things may get a little tight at the international space station next week when it is set to be a temporary home to 13 astronauts with the arrival of the shuttle Endeavour and its seven crew.

It will be the first time so many people have stayed on the orbiting station at once, and the 12 men and one woman will also represent the main countries involved in constructing the €71-billion-dollar outpost in space.

Endeavour is on target to launch this morning at 1117 GMT from Cape Canaveral in Florida, and so far the weather forecast is looking good, Nasa officials said.

"We're in really good shape to fly," said Mike Moses, chairman of the mission management team, with the clock already ticking to the launch.

The six Americans and one Canadian woman from the Endeavour will join another US astronaut and one more from Canada, as well as two Russians, a Belgian and Japan's Koichi Wakata who are currently living on the ISS.

Construction began on the ISS a decade ago, and the push is on to complete the building before Nasa ends its shuttle missions in September 2010.

Endeavour's crew are tasked with installing the final elements of the Japanese Kibo laboratory during their 16-day mission.

The station has become a sophisticated platform for scientific experiments after the installation of a European laboratory last year and the arrival of the hi-tech Japanese lab that is currently being completed.

It will be the 32nd mission to the ISS, which orbits 350 kilometres above Earth, and the last of three missions to assemble the Kibo laboratory.

Over the five planned spacewalks lasting some 32.5 hours, the astronauts will install a permanent 1.9-tonne platform to Kibo, which will serve as one of the station's porches for conducting experiments in the vacuum of space.

Endeavour will also deliver a large number of spare equipment, and bring up an unpressurised storage area for keeping the experiments that have been exposed to the extremes of space. It will also bring with it another platform that can be unfixed from the space station and then flown back to Earth in the Endeavour's cargo hold.

The team will also have to install six batteries for the station's oldest solar panels.

Nasa is seeking to make maximum use of its flights to the space station with only seven more planned after the Endeavour's trip before the shuttles are retired.

Senior Nasa official Bill Gerstenmaier has offered assurances that the space station has the capacity to play host to 13 astronauts at once, after a fourth solar panel was erected along with other equipment including toilets, a kitchen and a machine to recycle urine into drinking water.

But he acknowledged: "It's a very complex and challenging mission for the team."

The Endeavour will also deliver a new crew member for the ISS, American Tim Kopra, to replace Wakata, who will return to Earth on board the shuttle after arriving on the space station in March.

Should there be any hiccups forcing the launch to be postponed, Nasa officials will have just a short window of about five days to re-schedule the flight.

A Nasa moon probe, the Lunar Crater Observation and Sensing Satellite, is due to be launched via rocket on Wednesday from a nearby military base, and after that the next available date for Nasa launch is July 11 at the earliest.