Troubled mapping mission wraps
Shuttle sent to take detailed images of Earth collected shots of 75 percent of the planet's surface
Despite technical problems, the Shuttle Radar Topography Mission managed to complete 95 percent of its mission objectives and was ready to land Tuesday.
During the 11-day mission, radar-imaging devices scanned about 75 percent of the Earth's surface from Cape Horn on the southernmost coast of South America to Hudson Bay in Canada. The National Imaging and Mapping Agency will use the images to create more accurate and detailed 3-D maps.
The U.S. Geological Survey plans to use the images which show details of fault lines for earthquake studies. Data also could be used for land-use planning, civil engineering and military logistical planning.
NASA's fears about deploying and retracting the 197-foot mast used to capture the radar images were confirmed Monday, when the arm failed to return to the shuttle. NASA decided to cut the mission from 10 to nine days prior to the launch to allow for problems with the mast. After four attempts, the mast was retracted. If it had not responded, crews would had to release the mast into space.
The shuttle crew also faced other problems. A faulty fuel thruster, which maintains the mast's location, almost caused the mission to be cut another day. Additional fuel from the space shuttle was used to maintain the mast's altitude.
A backup recording system prevented the loss of data when the main system failed to recognize radar data during the fifth day of the mission, according to a NASA spokesperson. The mission recorded more than 330 tapes worth of information, which is equal to 20,600 compact disks.
The data will be copied and sent to NASA's Jet Propulsion Laboratory where it will be analyzed. It will take more than a year to analyze the information and another year to create the detailed maps.
Prior to this mission, aircraft, satellites and field exploration were used to collect data for topography maps. But cloud cover and steep terrain often prevented many areas from being accurately recorded.
More information about SRTM is available at www.jpl.nasa.gov/srtm.