The much-awaited return of space shuttle Discovery, with seven astronauts onboard, was delayed by a day as low clouds obscured the view of the landing strip at the Kennedy Space Center.
The shuttle, which had some thermal blanket dangling under the cockpit, was scheduled to land at 1417 IST at the
KSC after 13 days in space, but NASA delayed the touchdown initially by 90 minutes and later put it off till tomorrow as low clouds hovered over the space center.
'Due to low clouds at the Kennedy Space Center landing site, Mission Control Houston has waved off both landing
opportunities for space shuttle Discovery today,' a NASA statement said. 'The next opportunity is at 5:08 am EDT (1438 IST) Tuesday.'
"We've been working this pretty hard as I'm sure you can imagine from our silence down here," Mission Control radioed Discovery commander Eileen Collins. "We just can't get comfortable with the stability of the situation for this particular opportunity so we are going to officially wave you off for 24 hours."
Discovery's mission is the first human spaceflight since Columbia broke up on re-entry in February 2003, killing
India-born Kalpana Chawla and six other astronauts.
Though NASA prefers to land the shuttle at the KSC, it has planned to make available runways at the Edwards Air Force Base in California and at White Sands in New Mexico.
'There are several opportunities to land tomorrow, including two at the Kennedy Space Center in Florida and two
at Edwards Air Force Base in California,' a NASA statement said.
The astronauts had readied their spacecraft and were awaiting instructions from Mission Control to fire their orbital jets to return home when mission managers announced that 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 13-day mission which began on July 26.
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.
A pair of spacewalking astronauts replaced a failed gyroscope, which controls the orientation of the station, and
restored power to another. For the first time in three years yesterday, all four of the station's gyroscopes ran
simultaneously.
Stephen Robinson became the first astronaut ever to go beneath the space shuttle's belly while in orbit to gently tug
out two protruding thermal tile fillers.
Onboard the station, Commander Sergei Krikalev and NASA Station Science Officer John Phillips have returned to
their normal schedule.
Collins, Kelly and Mission Specialist Steve Robinson, who also serves as Discovery's Flight Engineer, and Mission
Specialist Andy Thomas will be on the flight deck for landing.
Mission Specialists Soichi Noguchi, Wendy Lawrence and Charlie Camarda will be on the shuttle's mid-deck.