Discovery waved off for landing ~Super Princess~

KENNEDY SPACE CENTER, Florida (CNN) -- "Unstable" weather conditions prompted NASA to scrub Discovery's scheduled landing Monday, the first space shuttle landing attempt since the Columbia disaster.

The next opportunity is scheduled for Tuesday at 5:07 a.m. ET at the Florida landing site.

"We just can't get comfortable with the stability of the situation for this particular opportunity. So we're going to officially wave you off for 24 hours," Ken Ham at Mission Control told the shuttle.

"OK, Houston we copy that. We'll be a wave off for today," responded shuttle Commander Eileen Collins.

The cloud cover, although within NASA's safety limits for landing, was enough to make mission controllers uncomfortable about attempting a Monday touchdown in Florida.

Mission controller LeRoy Cain said NASA's weather forecast for Tuesday morning at the Florida site called for similar conditions, including possible clouds, light and variable winds, and a chance for rain within 30 miles.

Alternative sites were being prepared at Edwards Air Force Base in California and at White Sands in New Mexico. "We'll land somewhere tomorrow," he said.

Officials would prefer to land at Kennedy Space Center to avoid the inconvenience of flying the shuttle back to its launch site from the alternative landing strips.

Mark Polansky, a pilot during a 2001 mission aboard the shuttle Atlantis, said the waiting is easier for orbiting crew members than it is for their families.

"It's much harder for people on the ground," Polansky said. "Loved ones don't know when their people are coming home."

Polansky and astronaut Nicholas Patrick are assigned to a shuttle mission aboard Discovery in 2006. Patrick said the orbiting astronauts have more than enough supplies to keep them until they can return.

"In between powering down today and preparing for Tuesday's landing attempt, they'll be taking care of some housekeeping and perhaps finding more time to be looking out the windows," Patrick said.

Following the decision to remain in space another day, Discovery received permission to re-open its payload bay doors and began powering down systems that had been poised to fire engines to take it out of orbit.

During Tuesday's de-orbital burn, the spacecraft's engines will ignite for about three minutes, slowing it enough to begin its fiery journey through the atmosphere.

Discovery's pilot, astronaut James Kelly, said Sunday that returning to Earth is much like riding on a runaway train.

"Once we start re-entering the atmosphere, you start seeing the plasma go by the windows," Kelly said, referring to colorful, super-hot gases.

It's "a very exciting and exhilarating process that ends with being at home," Kelly said.

Though it launches into orbit like a rocket, the shuttle returns to Earth like an airplane. As it begins to transition from space, computer-controlled jets guide the shuttle. Once the atmosphere thickens, Discovery's wing flaps and rudder steer it much like they would a conventional aircraft.

When the shuttle slows below the speed of sound, it triggers a sonic boom that alerts Florida residents that the spacecraft is returning home.

It was during re-entry in February 2003 that Columbia broke apart, killing its seven crew members.

Investigators later determined that super-heated gases that normally surround the orbiter as it returns to Earth entered Columbia's left wing through a hole created when insulating foam fell from the shuttle's fuel tank and struck the vehicle during launch.

The Columbia break-up left a trail of debris across Texas and Louisiana and resulted in vows from NASA that tighter safety precautions would be taken on future trips -- and that the problem of falling foam would be solved.

Under new guidelines, Discovery will follow a trajectory that takes it largely over ocean.

Mission STS-114 largely was designed to improve safety on future shuttle journeys, although the program has been suspended while NASA investigates its failure to solve the problem of foam falling from the shuttle's external liquid fuel tank during launch.

Video from the July 26 launch showed debris falling from the fuel tank, but NASA said it did not appear to have struck the orbiter. Once in space, Discovery's crew used cameras to scrutinize the craft's exterior for possible damage that might pose a threat during re-entry.

The shuttle spent most of the mission docked to the international space station, delivering much-needed supplies and performing maintenance on the outpost.

Astronaut Steve Robinson performed an unprecedented shuttle repair mission by plucking two pieces of filler material protruding between tiles on Discovery's underside. NASA wanted them removed to ensure they wouldn't overheat, damaging Discovery's belly during re-entry.

Mission controllers said an additional spacewalk to fix a damaged thermal blanket under one of the cockpit windows was not necessary.

Show all stories by   Author:  42515 ( Click here )