If weather cooperates, Endeavour will touch down at the Kennedy Space Center at 9:54 p.m. CST after completing 185 orbits of the Earth. A deorbit firing of the Shuttle's maneuvering engines will occur at 8:47 p.m. CST to slow the spacecraft's forward velocity, allowing it to drop back into the Earth's atmosphere. Returning as an unpowered, hypersonic glider, Endeavour will follow a ground track that takes it over the Mexico-Guatemala border and across the Gulf of Mexico, making U.S. landfall over the Ft. Meyers/Sarasota, Florida, area before heading in for a landing at runway 33.
If all goes as planned, Endeavour's cargo bay doors will swing shut at 6:07 p.m., after which the astronauts will climb into their launch and entry suits and strap into their seats. Commander Bob Cabana, Pilot Rick Sturckow and Flight Engineer Nancy Currie will be joined on the flight deck for entry by Mission Specialist Jim Newman, while crew mates Jerry Ross and Sergei Krikalev will be seated down on the middeck.
Forecasters are keeping a close watch on weather in the vicinity of the landing site, with current predictions calling for scattered clouds at 3,000 feet with a chance of showers within 30 miles of the Shuttle Landing Facility. Forecasters predict about a 70 percent chance of acceptable weather for the first of tonight's two landing opportunities.
If the forecast holds, Entry Flight Director John Shannon will give the green light to fire Endeavour's two orbital maneuvering system engines at 8:47 p.m. CST. The deorbit burn will slow the shuttle by 349 feet per second, allowing it to descend back to Earth. Landing is scheduled at 9:54 p.m. CST, completing a 4.6-million-mile mission.
Weather conditions are expected to be somewhat better for tonight's second landing opportunity at KSC, with forecasters indicating an 80 percent chance of favorable weather. For the second opportunity, a deorbit burn at 10:24 p.m. CST would see Endeavour land at 11:30 p.m. CST. Mission managers have decided not to call up landing support at the backup landing site at Edwards Air Force Base, Calif., for this evening's opportunities. However, Edwards will be called up for backup landing support on Wednesday should landing at KSC tonight be waved off.
The crew will remain at KSC on Wednesday, returning to Houston's Ellington Field about 2 p.m. Thursday.
Endeavour is orbiting the Earth at an altitude of 246 statute miles with all of its systems in excellent shape.