A high pressure system sitting over the eastern seaboard is expected to produce windy conditions that could result in cross winds in excess of acceptable limits at the time of today's planned landing. Mission managers will closely watch weather conditions in Florida today, working with the Spaceflight Meteorology Group in Houston and complemented by real-time weather observations by Chief Astronaut Charlie Precourt flying the Shuttle Training Aircraft at the landing site.
The crew was awakened at 5:17 a.m. today to begin landing preparations to the sounds of the U.S. Air Force theme "Off We Go Into the Wild Blue Yonder." Mission Commander - and Air Force Colonel - Brian Duffy quickly responded that "You had a couple of us standing and singing up here looking out the window, looking at the wild blue yonder and hoping to enter it today."
If weather conditions permit and the crew is given a "go" to begin their deorbit preparations, they will close Discovery's payload bay doors at 9:27 a.m., the crew will put on their pressurized launch and entry suits and strap into their seats just after 11 a.m. Entry Flight Director LeRoy Cain is expected to poll the flight control team for the final decision for the de-orbit burn 20 minutes prior to the planned firing of Discovery's orbital maneuvering system engines at 12:07 p.m. which will set the STS-92 crew up for a landing at KSC at 1:14 p.m. CDT. There is a back up landing opportunity one orbit later if needed. The second opportunity would involve a de-orbit burn at 1:43 p.m. and landing at 2:50 p.m. CDT.
For a landing on that first opportunity, at the time of the de-orbit burn, Discovery will be above the Indian Ocean, passing over the northern portion of Sumatra. The burn will last just under 3 ½ minutes and the change in velocity will cause Discovery to fall out of orbit and begin the trip home. A little more than 35 minutes later, while flying over the Pacific Ocean, South of Easter Island, the vehicle will begin to encounter the upper portions of Earth's atmosphere in the portion of the flight known as entry interface. With the Shuttle's speed still above Mach 25, temperatures outside the vehicle will quickly climb near 3,000 degrees F.
The final portion of Discovery's flight path will see the Shuttle pass over Central America along the Honduras-Nicaragua border, the western portion of the Caribbean Sea, the western most portion of Cuba and the Gulf of Mexico before crossing the Florida coastline, flying over the Everglades and Lake Okeechobee before arriving on the east coast of Florida near Cape Canaveral.
As Discovery reaches the vicinity of Kennedy Space Center, Commander Brian Duffy will take over manual control of the Shuttle. He will execute a 223-degree turn to line Discovery up for a final approach to runway 1-5 at KSC's Shuttle Landing Facility.
If all goes as planned and Discovery touches down on the 3 mile long runway at 1:14 p.m., it will have traveled approximately 4.5 million miles over 11 days, bringing to an end the 100th mission in Shuttle program history.