BEIJING, Jun 13 (Xinhuanet) -- Atlantis astronauts may use a sewing kit to repair a thermal blanket near the spacecraft's tail, which peeled during launch last week, according to NASA managers Tuesday.

    NASA managers have decided late Monday to extend the 11-day mission two extra days and add a fourth spacewalk so astronauts can repair a thermal blanket gap, which covers a 4-by-6-inch area over an engine pod.

    The thermal blankets are used to protect the shuttle from searing heat during re-entry, which could damage the shuttle.

    "This is the right thing to do," Atlantis commander Rick Sturckow told reporters from space Tuesday night.

    The rest of the shuttle appeared to be in fine shape, NASA said, although two sensors on the shuttle wing's leading edge had detected what seemed to be an impact by space debris.

    NASA has been cautious about any potential damage to the wing leading edge since the Columbia disaster in 2003 killed seven astronauts.

    Meanwhile, the International Space Station spread its new set of wings on Tuesday, with new solar arrays successfully unfurled.

    The solar arrays on the newly installed truss segment deployed to their full length with the assistance of the Atlantis crew.

    Each solar wing is 115 feet long and weighs more than 2,400 pounds. The entire solar array's wingspan is more than 240 feet. The array, which converts sunlight to electricity, is the station's third pair of solar panels.

    On Wednesday, an older solar array will be retracted during a later shuttle mission, which will allow the newly installed pair of panels to rotate and follow the sun.

    (Agencies)