Early Tuesday, Endeavour had already passed over and mapped a surface equivalent to the size of Africa, Australia and the North American continent, or some 100,000 square kilometers (38,610 square miles) per minute.

The data will be collected by some 300 high-density recording tapes which could fill about 13,500 compact discs.

New radar images of Brazil, South Africa and the South Island of New Zealand were unveiled this afternoon by elated scientists of the Shuttle Radar Topography Mission. "This snapshot of Earth will be used for decades to come," said deputy project scientist Dr. Tom Farr.

Mapping operations continued smoothly into the mission�s fifth day, with both radar and orbiter systems working flawlessly. By early afternoon, more than 29 million square miles had been mapped, representing more than 61 percent of the planned coverage for the mission. That�s equivalent to the combined area of North America, South America and Africa.

Flight controllers continue to troubleshoot a problem with a small nitrogen thruster on the end of the 200-foot-long mast, and are focusing on steps that can be implemented to conserve shuttle propellant.

Several steps already have been implemented, including relaxing the requirements for maintaining the mast�s attitude due to the better-than-expected stability of the mast.

Additional steps are under review for their potential propellant-saving potential. Optimism is increasing that these measures will enable Endeavour to complete its planned mapping operations.

Blue Team members Janice Voss and Mamoru Mohri spoke with reporters from CNN, NBC�s Today Show and KGO Radio in San Francisco earlier today. Voss, Mohri and Dom Gorie ended their day early this afternoon, and will be awakened to begin their sixth day on orbit at 10:14 tonight Central Time.

The Red Team -- Kevin Kregel, Janet Kavandi and Gerhard Thiele -- was awakened shortly after 10 this morning and promptly resumed mapping operations.

This afternoon, Kregel and Kavandi answered questions from students at the Kansas Cosmosphere in Hutchinson, KS; Sitting Bull College in Ft. Yates, ND; and Houston High School in San Antonio, TX.

This event was part of a NASA effort to encourage students to pursue careers in science, engineering and math.

All of Endeavour�s systems are functioning normally as it circles the Earth every 90 minutes at an altitude of about 150 miles. The next status report will be issued at 6 a.m. Wednesday, or as mission events warrant.