The early morning fog burned off as the sun rose, and Mission Control gave the seven astronauts the go-ahead to come home on time. "I guess you've been wondering, but you are 'go' for the deorbit burn," Mission Control radioed at practically the last minute.

Ilan Ramon, a colonel in Israel's air force and former fighter pilot, became the first man from his country to fly in space, and his presence resulted in an increase in security, not only for Columbia's Jan. 16 launch, but also for its landing. Space agency officials feared his presence might make the shuttle more of a terrorist target.

"We've taken all reasonable measures, and all of our landings so far since 9-11 have gone perfectly," said Lt. Col. Michael Rein, an Air Force spokesman.

Columbia's crew - Ramon and six Americans - completed all of their 80-plus experiments in orbit. They studied ant, bee and spider behavior in weightlessness as well as changes in flames and flower scents, and took measurements of atmospheric dust with a pair of Israeli cameras.

The 13 lab rats on board - part of a brain and heart study - had to face the guillotine following the flight so researchers could see up-close the effects of so much time in weightlessness. The insects and other animals had a brighter, longer future: the student experimenters were going to get them back and many of the youngsters planned to keep them, almost like pets.

All of the scientific objectives were accomplished during the round-the-clock laboratory mission, and some of the work may be continued aboard the international space station, researchers said. The only problem of note was a pair of malfunctioning dehumidifiers, which temporarily raised temperatures inside the laboratory to the low 80s, 10 degrees higher than desired.

Some of Columbia's crew members didn't want their time in space to end.

"Do we really have to come back?" astronaut David Brown jokingly asked Mission Control before the ride home.

NASA's next shuttle flight, a space station construction mission, is scheduled for March. The next time Columbia flies will be in November, when it carries into orbit educator-astronaut Barbara Morgan, who was the backup for Challenger crew member Christa McAuliffe in 1986.

---

On the Net:

NASA: http://spaceflight.nasa.gov

AP-ES-02-01-03 0820EST