Today, maybe tomorrow, could be perfect for space shuttle landing

CAPE CANAVERAL, Fla. -- NASA officials yesterday postponed the space shuttle Discovery's return to earth by a day, citing scattered cloud cover that could have limited visibility during landing.

The space agency has set two more potential early-morning landing times in Florida today, as well as backup landing times at Edwards Air Force base in California and the White Sands Missile Range in New Mexico.

''We will land somewhere on Tuesday," said Leroy Cain, flight director with the National Aeronautics and Space Administration.

Nevertheless, contingency plans for a landing tomorrow either at Kennedy Space Center or Edwards have also been made.

Today's weather forecast for Cape Canaveral is the same as yesterday morning: cloudy with a chance of rain. The two landing times in Florida today are 5:07 and 6:43 a.m. At Edwards, the available time slots are 8:12 and 9:47 a.m., while at White Sands, they are 6:39 and 8:13 a.m., all Eastern Daylight Time.

The decision was made just five minutes before Discovery was to begin descending into earth's atmosphere, the first time a shuttle has attempted to land since Columbia disintegrated on Feb. 1, 2003, just minutes into reentry.

After scrapping a 4:46 a.m. landing yesterday, conditions appeared to improve as the shuttle made its second landing attempt, scheduled for just after 6 a.m. A NASA plane buzzed the landing strip to check visibility. Conditions were clear and the weather forecast was good, said NASA weather officials. But Cain, citing ''unstable" cloud patterns in the area, decided to postpone the landing.

The shuttle crew acknowledged the decision and began another 24 hours of orbiting.

The decision was in keeping with the intense caution that has characterized this mission. After the Columbia disaster, NASA installed a video-monitoring system that has detected an unprecedented number of tiny flaws and glitches in the shuttle's delicate hull and underside, including one-inch protrusions of underbelly fabric strips that led to the first-ever midflight spacewalk repair last week.

As Discovery approached its landing time yesterday, there were no technical or mechanical problems with the craft, said NASA officials. Only the weather was a concern; it had rained in central Florida into the evening, and low-lying clouds floated across the area into the morning.

''We just can't get comfortable with the stability of the situation," Mission Control told the Discovery crew at 5:05 a.m. as the shuttle orbited over the Indian Ocean, where it was just about to rocket into the atmosphere when the much-anticipated landing was called off.