The shuttle, scheduled to take off from Cape Canaveral, Florida, yesterday at 1538 GMT (11.38pm Singapore time), will be commanded by Ms Pamela Melroy.

Greeting her at the space station will be skipper Peggy Whitson.

It will be the first time in the 50-year history of spaceflight that two women are in charge of two spacecraft at the same time.

'This is not something that was planned or orchestrated in any way,' said Ms Melroy, who will be only the second woman to command a space shuttle flight.

Her two-week mission was originally supposed to be completed before Ms Whitson's expedition.

Ms Whitson, the first woman in charge of a space station, arrived at the orbital outpost on Oct 12 with Russia's Yuri Malenchenko and Malaysia's Sheikh Muszaphar Shukor. Dr Muszaphar returned to Earth on Sunday.

ASSOCIATED PRESS