A view of the space shuttle Atlantis as it performs a fly-around of the space station

Bad weather is disrupting the landing plans of the U.S. space shuttle Atlantis for a second day, stretching out an already lengthy and trouble-filled mission.

After deciding to skip Friday's earliest opportunity to set down at Kennedy Space Center in the southeastern U.S. state of Florida, experts at the U.S. space agency, NASA, are deliberating whether to attempt landing the shuttle in Florida later or at an alternate site in the west coast state of California.

If the weather does not clear, there are more opportunities for landing the shuttle on Saturday. If it comes to that, engineers also may consider an alternate landing site in the southwestern U.S. state of New Mexico. But Florida is the preferred site because the Kennedy Space Center is the shuttle's permanent home.

Atlantis has enough fuel and supplies to stay in orbit until Sunday.

Atlantis is finishing a mission that involved docking at the International Space Station and conducting four spacewalks, to do construction and repairs on both the station and the shuttle. U.S. astronaut Clayton Anderson also was sent as the newest crew member of the orbital outpost. He replaced Sunita Williams, who set the record for the longest space flight by a woman during her six-month stay at the space station.

NASA engineers cleared the shuttle to return to Earth after determining that a repaired thermal blanket on the shuttle's exterior could withstand the intense heat of re-entering the atmosphere. The blanket was damaged on takeoff.