CAPE CANAVERAL, Fla. (Reuters) - Cloudy skies over its Florida landing site on Monday forced NASA to postpone the return to Earth of space shuttle Discovery, prolonging by at least a day the first shuttle mission since the 2003 Columbia disaster.
Flight directors tried twice to bring Discovery back to Earth after 13 days in orbit but decided the weather was too unpredictable to be sure shuttle commander Eileen Collins would have a clear view of the 3-mile, canal-lined runway at the Kennedy Space Center.
"We regret not getting you guys home today but we feel pretty confident about tomorrow," astronaut Ken Ham radioed from Mission Control in Houston to the Discovery crew.
"Well, you guys made the right decision and we're with you," replied Collins. "We're going to enjoy another day on orbit and we'll see you on Earth tomorrow."
Barring emergencies, NASA will only land the shuttle if there is at least 5 miles of visibility for the approach to the runway and no rain, lightning or thunderstorms within 35 miles.
NASA has several chances to land the shuttle on Tuesday, including opportunities at 5:07 a.m EDT (0907 GMT) or 6:43 a.m. EDT (1043 GMT) in Florida and at 8:12 a.m. EDT (1212 GMT) at the primary backup site in California.
Collins planned to tweak Discovery's orbit slightly so that if the shuttle had to land in California, it would not fly over Los Angeles. Since the Columbia accident, which showered debris over Texas and Louisiana when the ship broke apart in the air, NASA tries to avoid flying over heavily populated areas in case of another accident.
Shuttle program deputy manager Wayne Hale said NASA also would staff its second backup landing site in New Mexico. The ship has enough supplies to safely stay in orbit through Wednesday, if weather or technical issues prevent landing on Tuesday.
The landing will bring to a close NASA's first shuttle mission since Discovery's sister ship, Columbia, was destroyed on Feb. 1, 2003, 16 minutes from landing.
NASA did not know that the ship's wing had been critically damaged during launch by a piece of falling debris. As Columbia plowed through the atmosphere 16 days later for landing, superheated gases blasted into the hole, melting the ship. The seven astronauts on board died.
While Discovery's descent will test the mettle of Mission Control, for the first time in the 24-year shuttle program, ground controllers know the condition of the shuttle's heat shield.
After the accident, NASA developed on-orbit laser imaging tools and inspection techniques, which not only were tested during Discovery's flight, but important in determining that an unplanned spacewalk was needed to make a minor but unprecedented repair to the ship's heat shield.
The success of the inspection tools was overshadowed by the failure of the shuttle's fuel tank, the primary upgrade after the Columbia accident. Columbia's wing damage was caused by a piece of foam insulation that fell off the tank during launch.
A chunk of foam almost as large as the one that damaged Columbia flew off Discovery's tank as well. It did not strike the ship, but NASA again suspended shuttle flights until the problem is solved.
NASA has set Sept. 22 as a possible launch date for the next shuttle mission. But Hale has said he does not believe the target date is realistic.
Discovery spent nine days at the International Space Station on a critical servicing and resupply mission. In addition to replenishing the station's pantry, water supplies and other critical gear, the shuttle delivered a new gyroscope to the outpost and revived a second failed device, restoring full service to the steering system for the first time in more than three years. SOURCE