Indian American astronaut Sunita Williams will not return home as scheduled.

Sunita's seven month-long stay on board the International Space Station has been extended following a hail storm last February that damaged the fuel tank of the space shuttle Atlantis. The hail storm has disrupted NASA's flight schedule for the year.

Depending on whether the fuel tank can be repaired or replaced, Atlantis will not be ready to fly until the middle of May or June.

"We are assessing a remote possibility of bringing Williams back to Earth aboard Atlantis. That is something we are looking at as we learn more about what will go on with the shuttle schedule," NASA's space station program manager Kirk Shireman told media persons at a briefing at the Johnson Space Centre.

Williams has been kept up to date on the developments since the February 26 hail storm and is taking the uncertainty over her return to Earth in stride, he added.

Flight surgeon Dave Alexander said her physical fitness, mental well-being and radiation exposure will be monitored carefully, but at the moment, the predictions are that she can stay up for an extended period of time