Discovery astronauts gave their spacecraft a final inspection yesterday and said they were confident of a safe return to Earth on the first shuttle flight since the 2003 Columbia disaster.

They checked out flight control systems and used a laptop computer to practice landings before today?s touchdown in Florida. ?Discovery is in absolutely great shape?, shuttle commander Eileen Collins said in a media interview from space. ?I?m pretty confident about the entry (into the atmosphere) and I?m thinking about the landing. I have had a lot of thoughts about Columbia and I will have thoughts after the landing, but we?re all going to be very focused tomorrow on the job at hand?, she said.

After 13 days in orbit, Discovery was scheduled to land at Kennedy Space Center on Florida?s east coast at 4:47 a.m. (0847 GMT) today. Weather forecasts indicated favorable conditions for landing, NASA flight commentator James Hartsfield said. If problems arose, Discovery could be waved off to an alternate landing site in California or New Mexico on Tuesday.

The U.S. space agency has pronounced the spacecraft fit to withstand the fiery descent into the Earth?s atmosphere that brought the demise of Columbia on Feb. 1, 2003. But NASA officials admit the first return home since that tragedy, which killed the seven astronauts on board, will be a nail-biter until the shuttle safely lands. ?We are going to be pretty darn happy to get to wheels-stop and see this good crew step off?, said lead flight director Paul Hill.

Columbia was a few minutes from landing in Florida when it broke apart over Texas as superheated gases generated by re-entry penetrated its structure through a hole in the wing heat shield.

The wing had been struck by a briefcase-size piece of insulating foam that broke loose from its external fuel tank at launch 16 days before. A subsequent investigation criticized the agency for becoming too lax and resulted in stiff safety standards for future shuttle flights.

<B>Doom of Columbia</B>

NASA spent 2 1/2 years and $1 billion making safety upgrades so the stakes are high for today?s landing to prove it can still conduct reliable space flights. ?It?ll be a huge sense of accomplishment having gotten through the last two years and demonstrated that we still know how to do this very difficult and dangerous business?, Hill said.

?I guess you almost have to thank the Columbia crew. The sacrifice they made allowed us to get a lot smarter about it?, said Discovery pilot Jim Kelly. Discovery?s flight began badly when loose tank foam like that which doomed Columbia was seen at the July 26 launch. NASA quickly suspended additional shuttle flights until the foam problem is solved.

Then, photographic and laser inspections of the shuttle in space, conducted for the first time as part of the new safety regime, showed minor nicks to Discovery?s heat shield, two protruding cloth strips from its belly and a rip in an insulating cloth near the commander?s window.

Only the protruding strips were deemed sufficiently hazardous for a fix so Robinson went on an unprecedented spacewalk to remove them. He easily pulled them out with his gloved hand.

The damage issues overshadowed Discovery?s accomplishments, which included a resupply of the International Space Station and a fix of broken gyroscopes that keep the station positioned properly. The shuttle left the station on Saturday.

<B>Jeff FRANKS</B>