The first swath was begun as the orbiter crossed over southern Asia and continued until Endeavour flew over the continent�s eastern coast and moved over the northern Pacific Ocean. The mapping will continue through the mission until the antenna mast is retracted before landing.

Because of the 24-hour-a-day activity aboard Endeavour, the six crewmembers are divided into two teams. Blue Team members Dom Gorie, Janice Voss and Mamoru Mohri began the first mapping swath, covering a 140-mile-wide path, at about 11:31 p.m. Friday.

It was the beginning of coverage of more than 70 percent of the Earth�s land surface. The mapping will cover an area between 60 degrees north and 56 degrees south, where about 95 percent of the Earth�s population lives.

The Red Team, led by Mission Commander Kevin Kregel, includes Mission Specialists Janet Kavandi and Gerhardt Thiele. Their first shift was intense. It included deployment and checkout of the almost 200-foot mast supporting the outboard antenna structure.

It is the largest rigid structure ever deployed in space. The Red Team began its sleep period at about 10:45 p.m. Friday and are scheduled to be awakened at 6:44 this morning.

After mast deployment, tests revealed that the mast�s damping system, designed as a kind of a shock absorber for the mast, was not working as expected. Flight controllers decided to leave the dampers in their locked position. Calculations showed that the mast was at no risk without the dampers activated.

All planned science data takes have been acquired successfully and all indications from the telemetry show that the radars are performing nominally. Data has been sent to JPL for analysis and early indications are that the data is of excellent quality. Additional reports about mapping results are expected about 12:00 noon CST.

Shortly after 5:30 a.m. Saturday, Voss and Gorie held a news conference with correspondents from NBC and CNN.

Saturday is scheduled to be the first full day of Shuttle Radar Topography Mission mapping. Endeavour systems continued to function normally.

Space Shuttle Endeavour lifted off from KSC's Launch Pad 39A at 12:43:40 p.m. EST. With excellent weather conditions and a virtually flawless countdown, the six-member crew began their mission about 13 minutes later than planned.

Launch controllers decided to extend the standard T-9 minute hold to allow engineers enough time to resolve three minor technical issues.

During the T-9 minute built in hold, engineers concluded evaluations of four superficial cracks in the thermal foam on the lower side of Endeavour's external tank. They determined that the cracks were too shallow to cause ice or debris concerns.

Shuttle engineers successfully repeated a pressure leak test of the orbiter's crew compartment that initially showed a slight variance in the pressure and confirmed the orbiter's readiness to proceed toward launch.

Also, a meter that was giving intermittent pressure readings from Endeavour's main propulsion system was exonerated as alternate sensors confirmed good data.

Finally, managers determined that a fluctuating reading from Endeavour's hydraulic system was a normal condition. Following a decision to resume the countdown no further issues were worked through liftoff.

The two solid rocket booster recovery ships, Freedom Star and Liberty Star, deployed into the Atlantic Ocean yesterday and are currently on station with the STS-99 boosters.

Depending upon weather conditions during recovery operations, the ships are expected to arrive at Hangar AF Sunday at 8 a.m. and 10 a.m. Preliminary inspections will commence on Sunday and booster disassembly begins Monday.