Flight controllers are closely monitoring the weather at the Kennedy Space Center and at Edwards Air Force Base. High winds and possible cloud cover are forecast for Kennedy that could prohibit a landing there. The forecast for Edwards calls for acceptable landing weather.
To land on the first opportunity to Florida, Endeavour would fire its engines to begin its descent at 2:53 p.m. CST. For the second Florida landing opportunity, Endeavour would fire its engines at 4:24 p.m. to leave orbit. For a landing in California, Endeavour would fire its engines at 5:51 p.m. CST.
Along with the six astronauts, aboard Endeavour are 332 high-density tapes from the Shuttle Radar Topography Mission containing data that will be used to produce global maps more accurate and more unified than any available today. During 222 hours and 23 minutes of operation, Endeavour's radar covered 99.98 percent of the planned mapping area - land between 60 degrees north latitude and 56 degrees south latitude - at least once. About 94.6 percent of it was covered twice. Only about 80,000 square miles in scattered areas remained unimaged, most of them in North America and most already well mapped by other methods. The data on the tapes would fill about 20,000 CD's. The total area mapped is more than 47.6 million square miles.
Also aboard Endeavour is a student experiment called EarthKAM which took 2,715 digital photos during the mission through an overhead flight-deck window. The NASA-sponsored program lets middle school students select photo targets and receive the images via the Internet. The pictures are used in classroom projects on Earth science, geography, mathematics and space science. More than 75 middle schools around the world participated in the experiment, which set a record. On four previous flights combined, EarthKAM sent down a total of 2,018 images.
The last Space Shuttle mission to land at Edwards was STS-76 in March 1996. Since then, 20 missions have landed at Kennedy.