An aerial view of the shuttle runway at Kennedy Space Center. Photo: NASA-KSC

Flush with success, the Endeavour astronauts tested the shuttle's re-entry systems and packed up Sunday for a landing Monday evening at the Kennedy Space Center to close out the 101st shuttle mission.

With commander Brent Jett and pilot Michael Bloomfield at the controls, Endeavour is scheduled to touch down on runway 15 at 6:03:45 p.m. EST (2304 GMT) to close out a 10-day 19-hour 57-minute 45-second mission spanning 4.4 million miles and 170 complete orbits since blastoff Nov. 30.

"We have two opportunities to the Kennedy Space Center," said entry flight director Leroy Cain. "The weather outlook for tomorrow (Monday) is very good at KSC. We do have a slight chance for some showers and rain in the forecast, but it's a little too early to tell how that's going to pan out for sure. We do have a good forecast for Tuesday as well."

Playing it safe, however, NASA managers decided Sunday to staff Edwards Air Force Base, Calif., Monday in case a frontal system reaches central Florida faster than expected and the forecast deteriorates.

"There's some uncertainty in the forecast at KSC for the next couple of days," Cain explained.

"So with some concern with respect to our ability to forecast the movement of the front to the degree of accuracy we'd like, we elected to go ahead and activate Edwards. It's an insurance policy for us. Again, KSC looks good for tomorrow."

The Endeavour astronauts have overlapping landing opportunities at the Kennedy Space Center and Edwards, with a Florida-only deorbit opportunity on orbit 170, California and Florida landing opportunities on orbit 171 and a California-only opportunity on orbit 172.

"We plan to land at KSC tomorrow if the forecast holds out," Cain said. "If we were to get into some unforeseen situation and not get into Kennedy tomorrow -- and we had a deteriorating forecast for Tuesday -- then we would start thinking about our options as far as Edwards is concerned."

Translation: They'll check the weather again Monday. If the forecast changes significantly, Endeavour's crew could be diverted to California Monday night.

"The orbiter's in great shape, the crew's in good spirits, we're ready to come in and do entry and landing," Cain said.