Space shuttle Discovery is all set to return to Earth on Tuesday after a day's delay due to low clouds at the Kennedy Space Center near Houston as NASA kept a close watch on the weather in Florida and at alternate landing facilities in California and New Mexico.
Weather conditions at the KSC are expected to be similar to those on Monday when NASA called off a planned touchdown at the Florida seashore facility because clouds affected visibility of the runway.
The shuttle, which had some thermal blanket dangling under the cockpit, was scheduled to land at 1417 IST on Monday at the KSC after 13 days in space. However, NASA delayed the touchdown first by 90 minutes and later put it off till Tuesday.
"Due to low clouds at the Kennedy Space Center landing site, Mission Control Houston has waved off both landing opportunities for Space Shuttle Discovery on Monday. The next opportunity is at 5:08 AM EDT (1438 IST) Tuesday," a NASA statement said.
Forecasts for the Edwards Air Force Base in California were for 'acceptable conditions for landing,' while NASA said there could be showers over the White Sands Missile Range in New Mexico.
The space center is the preferred landing site and the California base is the second option, followed by New Mexico, but personnel at all three facilities are making preparations for Discovery's landing.
Meanwhile, the 7 astronauts onboard the Discovery were in an upbeat mood as they woke up to the tune of the Beatles' 'Good Day Sunshine' to prepare for their scheduled return to Earth.
"We sure hope that we get our feet on the ground today," mission specialist Wendy Lawrence told mission control.
Discovery's mission is the first human spaceflight since Columbia broke up on re-entry in February 2003, killing India-born Kalpana Chawla and 6 other astronauts.
Also read: Discovery blasts off
Discovery's crew had readied their spacecraft and were awaiting instructions from Mission Control to fire their orbital jets to return home when mission managers announced low clouds over Cape Canaveral would postpone the landing.
The shuttle's 13-day mission to the International Space Station could be the last one for a long while as NASA grounded the fleet after some insulating foam broke off Discovery's external fuel tank during liftoff.
A similar foam, which came off during the January 16, 2003 launch of Columbia, had fatally damaged the shuttle.
The crew carried out emergency repairs in orbit and there were concerns that a tear to a thermal blanket just outside the cockpit could pose a new danger. But NASA officials said the return would be safe.
The space agency had carried out changes in the shuttle structure and introduced new repair mechanisms, which were put to test by Discovery astronauts during their mission which began on July 26.
Also read: Discovery heading home, bids ISS adieu
During their stay at the ISS, the astronauts resupplied the orbiting lab and removed broken equipment and trash -- one of the main goals of the mission.