Florida's fickle weather left the U.S. space agency holding a bag of clear, sunny sky today at the time the shuttle Challenger had originally planned to lift off. The launch had been postponed because of expected poor weather.

The delay -- until Monday at 9:37 a.m. EST -- disappointed, at least temporarily, thousands of schoolchildren, teachers and other visitors and dignitaries who had gathered here to watch social studies teacher Christa McAuliffe blast off as what she calls the first "ordinary person" in space. Most reportedly planned to stay the extra day.

McAuliffe and the other six crew members were given Super Bowl Sunday off, National Aeronautics and Space Administration aide Sarah Keegan said. "It is a reasonable assumption" that they would be watching the big game, at least until their 7 p.m. prelaunch bedtime. "They might get special dispensation" to stay up a little later to find out who wins, she added. "Astronauts do tend to be interested in sports events."

Spacecraft Commander Francis R. (Dick) Scobee and pilot Michael J. Smith, a Navy commander, spent part of the day flying T38 training jets, reviewing flight data and weather reports, she said.

Space agency officials have become accustomed to being foiled by the notoriously unpredictable weather here.

The weather twice delayed a launch of Challenger's sister ship, Columbia, earlier this month and caused the craft to land three days late. Even then, it had to be diverted to California.

Late Saturday night, NASA officials postponed the Challenger flight because of the threat of thunderstorms riding in along with a cold front.

They made their decision just before time to start filling Challenger's external fuel tank with supercold liquid hydrogen and oxygen. Unexpectedly, about two hours later, "a low pressure system developed in Georgia that slowed the front down" and left the launch pad in the clear, NASA spokesman Ed Campion said. "We were only off by about four hours."

Clouds and rain were rolling in over the spaceport by midday as the stalled front finally passed through.

Weather forecasts for Monday morning are better, with both visibility and wind speeds "within acceptable margins," he said.