Bad weather in Florida forced NASA to cancel the Thursday landing of STS-117 that was to bring back Sunita Williams and six others astronauts from space, resulting in Atlantis' crew spending an extra day in space.
Thunderstorms within 55 kilometers and clouds within 8,000 feet of the landing strip at Kennedy Space Center forced mission managers to skip the first landing opportunity at 2220 hours IST for a 2325 hours IST touchdown in Cape Canaveral, Florida.
Controllers and the Spaceflight Meteorology Group will closely monitor forecasts for Friday's opportunities in Florida and at Edwards Air Force Base in California.
Atlantis has four landing opportunities available on Friday. The first opportunity Friday is on Orbit 218 and calls for a de-orbit burn at 2244 hours IST. The second is on Orbit 219, which calls for the de-orbit burn to begin at 0020 hours IST and landing to occur at 0121 hours IST at Kennedy.
If Florida weather does not cooperate, two opportunities are available at Edwards Air Force Base in California.
The first landing opportunity is at 0149 hours IST on Saturday and landing at 0252 hours IST at Edwards.
The final opportunity is one orbit later with the de-orbit burn at 0325 hours IST and the landing at 0426 hours IST at Edwards.
NASA managers prefer landing at Kennedy since there would be less cost and time in preparing Atlantis for its next mission in December.
It would cost $1.7 million and take up to 10 days to bring the shuttle back to Florida from California aboard a jumbo jet.
Attempting to land so close to rain or clouds would violate flight rules, NASA said.
With the imminent return of Williams, a Needham resident, Deepak Pandya, her father, said he is focusing on the joy of the occasion rather than the dangers.
"We are God-loving people and we leave everything in the hands of God," he said.
Pandya and his wife, Bonnie, will wait for Williams in Houston, at the NASA headquarters.
Only Sunita's husband, Michael, will be allowed to meet with the astronaut immediately after her landing in Florida from her six-month mission, said Pandya.
Meanwhile, the crew closed Atlantis' payload bay doors on Thursday morning in preparation for a landing that would mark the end of a successful mission to the International Space Station.
Chief Astronaut Steve Lindsey is providing additional weather information as he flies a T-38 aircraft in the vicinity of the landing facility.
Atlantis was launched on June eight and arrived at the space station June 10. While at the orbital outpost, the crew installed the Starboard 3 and 4 truss segment and conducted four spacewalks to activate it.
During the third spacewalk, the crew repaired an out of position thermal blanket on the left orbital maneuvering system pod.
Atlantis also delivered a new station crew member, Flight Engineer Clayton Anderson. He replaced Williams, who is the new record holder for a long-duration single spaceflight for a woman. She arrived at the station in December with STS-116.
Williams, 41, set a record Saturday for the longest uninterrupted space flight by a woman -- passing the previous record of 188 days and four hours.
She logged 29 hours and 17 minutes in four space walks during her trip, eclipsing the record held by astronaut Kathryn Thornton for most space-walk time by a woman.
And in April, she became the first astronaut to run a marathon in orbit -- on a treadmill, finishing it in four hours and 24 minutes.
Additional Reportage: PTI
Samosas, hot bath and NASA honour for Sunita Williams
Coverage: Sunita Williams in Space
Sunita Williams speaks from space