STS-99 Status Report # 19

Sunday, February 20, 2000 – 6:00 a.m. CST

Endeavour’s astronauts are looking forward to using one more small bonus in mapping operations time. They were given an additional 10 minutes, bringing the total to nine days, 18 hours and 10 minutes. The additional minutes have been added to allow one more mapping pass across Australia, rather than turning off the radar just as the spacecraft approaches the nation’s coastline.

So far, the Shuttle Radar Topography Mission has imaged 44.7 million square miles, or about 93.9 percent of the target area, at least once. About 33.4 million square miles or 70.1 percent of the target area has been imaged at least twice. The target area extends from 60 degrees north latitude to 56 degrees south latitude. That covers all the Southern Hemisphere landmasses except Antarctica, and Northern Hemisphere land south of Hudson Bay and St. Petersburg, Russia. It is home to about 95 percent of Earth’s population.

At the scheduled end of mapping operations, more than 99.9 percent of the area will have been imaged at least once. More than 94.6 percent of it will be covered at least twice, and almost half will be imaged at least three times. All but about 80,000 square miles of targeted land will have been covered. The areas that will not be covered are in small, scattered segments, mostly in North America and most of them already accurately mapped.

Endeavour’s radar, gathering data in 140-mile-wide swaths as the spacecraft orbits at 17,500 miles per hour, images 40,000 square miles each hour. Data from this mission will, after a year or more of processing, produce the most accurate and most uniform global topography maps ever made.

The EarthKAM, a digital camera mounted at an overhead window on Endeavour’s flight deck, has sent down about 2,200 images so far, and the number is growing. On four previous shuttle flights EarthKAM sent down a total of 2,018 images.

The camera takes pictures for middle school students working on projects in Earth science, geography, space sciences and other topics. Through the Internet, their schools’ mission operations centers are linked to the EarthKAM Mission Operations Center at the University of California at San Diego, which sends up photo targets and receives the images. Except for setup, initial camera pointing and lens changes, no crew involvement is required for normal operations.