WASHINGTON, Aug. 10 (Xinhua) -- NASA said late Friday that it detected an gouge on Endeavour's belly after the shuttle docked with the International Space Station.

The gouge was spotted in zoom-in photography taken by the station crew before the linkup when the shuttle conducted the back flip procedure.

Endeavour Mission manager John Shannon told a news conference that NASA was trying to determine the extent of the apparent damage. "What this means, I don't know at this point," he said.

NASA engineers said that the gouge was possibly caused by ice that broke off the fuel tank shortly after Wednesday's liftoff.

On Sunday, Endeavour astronauts will inspect the damaged area extensively to determine the exact size of the gouge, according to Shannon. And then NASA engineers will give further analyses to determine whether it is severe enough to call for an in-orbit repair by space walkers.

Several hours after the linkup, Endeavour crew activated the new power transfer system onboard the shuttle. The system can convert and transfer power form space station to the docked shuttle Endeavour, which can extend its stay at the orbital outpost.

If the system works as expected, NASA mission managers could elect to extend Endeavour's mission from 11 to 14 days and increase the number of spacewalks from three to four.

Endeavour docks with space station

The U.S. space shuttle Endeavour docks with the International Space Station at 2:02 p.m. EDT (1802 GMT) on Friday, ending a nearly-two-day chase, according to NASA TV. (Xinhua/AFP Photo)

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WASHINGTON, Aug. 10 (Xinhua) -- The U.S. space shuttle Endeavour docks with the International Space Station at 2:02 p.m. EDT (1802 GMT) on Friday, ending a nearly-two-day chase, according to NASA TV.

The smooth linkup of the two vehicles while flying over the South Pacific brings the two astronaut crews together more than 200 miles above the Earth. Full story

The U.S. space shuttle Endeavour docks with the International Space Station at 2:02 p.m. EDT (1802 GMT) on Friday, ending a nearly-two-day chase, according to NASA TV. Xinhua/AFP Photo)

Photo Gallery>>>

The U.S. space shuttle Endeavour docks with the International Space Station at 2:02 p.m. EDT (1802 GMT) on Friday, ending a nearly-two-day chase, according to NASA TV.(Xinhua/AFP Photo)