Shuttle raises space station orbit

Another new battery goes into the ISS

The shuttle Atlantis will push the International Space Station towards a new orbit on Wednesday - after a successful start to the operation.

On Tuesday, Atlantis fired its steering jets 27 times in the course of 58 minutes to boost the height of the space laboratory by about 14 kilometres (nine miles).

Shuttle comander Commander James Halsell Jr will repeat the firing process not only on Wednesday but also on Thursday. By the time Atlantis undocks to return to Earth, the average altitude of the ISS will have increased by a total of about 43 kilometres (27 miles).

This will put it closer to the optimum orbit for a link-up with the Russian Zvezda living quarters module which is planned for launch in July.

"It was basically bang on the money,"' Mission control said of the manoeuvre that made the solar wings on the station sway ever so slightly. "Perfectly done."

New power units

The astronauts popped another fresh battery into the ISS, to add to the two installed the previous day. The ISS needs four new power units after careless overcharging by flight controllers on the ground left the station with only two good batteries out of six.

The seven-member crew have also installed three new fire extinguishers in the space station, taking away the expired units, launched with the original space station compartments in late 1998. They have also put in new smoke detectors.

In total, the Atlantis crew brought up a total of 1.5 tonnes of equipment and provisions that must be transferred to the station for use by future inhabitants of the ISS.

Fortunately for the astronauts, the heat in which they have had to work has been reduced.

The 30C (86F) heat they encountered upon entering the space station had dropped by a few degrees on Tuesday. Nasa had cranked up the heat to prevent condensation from forming inside the space station once the shuttle arrived for the first visit in a year.

First inhabitants

Space station flight director Paul Hill said everything had looked the way it should - no mould, no dew.

"It looked like the last time we were here,'' Hill told reporters, "which I guess is a good thing.''

Work to finish the giant space laboratory will require some 40 space missions between now and 2005.

The ISS will eventually house six- and seven-member crews who will rotate after stays of about five months each, with the first crew, comprising one US astronaut and two Russians, to arrive late this year.

The space station, a joint venture involving the United States, Russia, Europe, Japan and Canada, is expected to cost $60bn when completed. It will be one of the brightest objects in the evening sky and have as much pressurised living space as a Boeing 747 aircraft.