CAPE CANAVERAL, Fla. — Space shuttle Atlantis and its astronauts will spend yet another day in orbit.

NASA called off all landing attempts for today because of thunderstorms in Florida. Mission Control told the seven astronauts that the weather was not cooperating at the main touchdown site at Kennedy Space Center, but that it was looking up for Sunday. So Mission Control decided to keep the astronauts in orbit a 13th day rather than head to the backup landing site in California.

Thunderstorms also thwarted Friday's landing attempts.

Atlantis and its crew are trying to wind up their Hubble Space Telescope repair mission. It was NASA's last visit to the 19-year-old observatory. The $1 billion overhaul should keep the telescope working for another five to 10 years.