Indian-American Sunita Williams and six other astronauts of Atlantis prepared for a reunion with their families as they return to Houston on Saturday from California, where the space shuttle landed after a 14-day mission.

The families of the astronauts were at Kennedy Space Centre in Florida [Images], where they were expecting the shuttle to land, but poor weather conditions forced the mission managers to divert it to an alternative site -- the Edwards Air Force Base in California.

Following a smooth touchdown at 0119 IST, shuttle commander Rick Sturckow said, "It's just great to be back on planet Earth. There were a lot of challenges on this mission and they were all dramatic. All the solutions worked well."

"The astronauts are set to return to their home base, Johnson Space Centre in Houston, on Saturday," the NASA [Images] said.

Atlantis may be returned to Kennedy Space Center in six or seven days, it said.

The return of the shuttle to earth also marked the end of a record-setting spaceflight by Mission Specialist Williams.

The 41-year-old crossed the milestone for longest uninterrupted stay by a woman in space on Saturday last surpassing the 188-day, four-hour mark set by Shannon Lucid of the US on a 1996 mission to the Russian Mir space station.

She had set off from Cape Canaveral in December nine last year on space shuttle Discovery and lived on the International Space Station [Images] for six months before switching places on the Atlantis crew with Clayton Anderson.

When Atlantis landed, Williams had accumulated 194 days, 18 hours and 58 minutes during her spaceflight.

Although it is only her first space flight, Williams became the world's most experienced woman walker in space on February four with four excursions clocking over 29 hours and 17 minutes to top Kathy Thornton's 21-hour space walking record.

During her stay at the space station, Williams has conducted experiments across a wide variety of fields, including human life sciences, physical sciences and earth observation as well as education and technology demonstrations.

Some of these experiments give scientists critical insight into the effects of weightlessness on human bodies while others show ways to prevent effects already known about like muscle and bone loss.

In addition to rigorous exercise, Williams also collected and stored her blood while in space to add to an ongoing study on nutrition, another key element of living in space for long stretches of time.

The results of this study may impact nutritional requirements and food systems developed for future ventures in space.

During the 14-day visit to the international space station, the Atlantis crew installed a new truss segment, unfurled a pair of solar panels and activated a rotating joint that allows the new solar arrays to track the sun.