Indian American astronaut Sunita Williams is all set to be the world's most experienced woman space-walker as she gets ready to undertake a 6.5-hour spacewalk from the International Space Station along with fellow astronaut Mike Lopez-Alegria.

The first of a record four spacewalks planned during the next month is scheduled to begin 0900 hours CST (2030 hours IST) on Wednesday. The other spacewalks have been planned for February 4, 8 and 22.

The first three spacewalks will originate from the station's Quest airlock and the astronauts will use US spacesuits. Lopez-Alegria and cosmonaut Mikhail Tyurin will use Russian spacesuits for the last spacewalk and will exit the station from the Pirs airlock.

The three US spacewalks will rearrange the station's cooling system, bringing online new portions of the system that were activated during a shuttle mission in December 2006. The Russian spacewalk will free a stuck antenna on the ISS Progress 23 cargo craft docked to the aft end of the station, ensuring that craft can safely undock in April.

The construction of the $100 billion ISS began in 1998 following a joint venture by the United States, Japan, Russia, Canada, Japan and 11 participating nations of the European Space Agency, with Brazil and Italy as payload participants.