February 22, 2000 -The six astronauts aboard Space Shuttle Endeavour glided to a smooth landing at the Kennedy Space Center at sunset today, wrapping up their 11-day radar mapping mission, the first human space flight of the 21st century. With Commander Kevin Kregel at the controls, Endeavour touched down at 6:22 p.m Central time on Runway 33 at the three mile long Shuttle Landing Facility to complete a mission spanning almost 4.7 million statute miles.

Pilot Dom Gorie, Flight Engineer Janet Kavandi and Mission Specialist Janice Voss joined Kregel on the flight deck for entry and landing. Mission Specialist Mamoru Mohri from NASDA, the Japanese space agency, and European Space Agency astronaut Gerhard Thiele were seated down in the middeck. The end of the STS-99 mission marked the 21st consecutive landing at the Florida spaceport.

After waving off the first landing opportunity of the day because of high cross winds at the landing site, the crew was given a "go" to perform the deorbit burn which came at 4:24 p.m. Central time and caused Endeavour to fall out of its 150 statute mile high orbit to start the journey home to the Kennedy Space Center.

February 21, 2000 - After wrapping up mapping operations at 6:54 a.m. Eastern time today with a final pass over Australia, Endeavour's crew retracted the 200-foot mast into its payload bay canister. The mast, the longest rigid structure ever deployed in space, supported the Shuttle Radar Topography Mission's external antenna structure during more than 222 hours of data gathering. Mast retraction proceeded smoothly as each of its 87 external sections, or bays, folded into the nine-foot-long canister during the 18-minute retraction procedure. Final mast stowage was delayed when the three latches on the lid of the mast canister failed to engage as expected. The first two efforts failed to secure the latches, but the third attempt succeeded and all three latches on the mast canister were activated at 10:50 a.m. Eastern time.

During 225 hours of operation during this mission, EarthKam took 2,715 images. Over 75 middle schools from around the world participated. The previous record number of images for a single flight was 670 on STS-86. The total number of images for this flight alone far exceeded the combined total from all previous flights.

February 20, 2000 - Earth radar mapping continues smoothly on its last full day with Endeavour's crew scheduled to wrap up operations early Monday morning at 6:53 Eastern Time. As of 1:00 p.m. today, 99 percent, or about 47 million square miles of the target area had been mapped once. More than 87 percent of the target area ­ nearly 42 million square miles ­ has been mapped twice. With another 10 minutes added to mapping operations, complete mapping of Australia will be completed with Flinders Island on the northeast corner of Tasmania being the final area mapped.

The additional 10 minutes of mapping brings the total imaging time to nine days, 18 hours, 10 minutes, which equates to 99.96 percent of the planned coverage area being mapped during the mission. The coverage area extends from Hudson Bay in the north to the tip of South America, an area equal to 47.6 million square miles. Only 80,000 square miles of the target area ­ about the size of West Virginia ­ will remain unmapped by the end of mapping operations. However, the majority of this unmapped area is in North America and already has been accurately mapped.

February 19, 2000 - Following yesterday's decision by mission managers to extend mapping operations, Endeavour's astronauts are set to continue collecting data until 6:44 a.m. Eastern time Monday. At that point preparations will begin to stow the 200-foot-long mast for the remainder of the mission. This 9-hour extension allows for almost 100 percent of the planned coverage of the Shuttle Radar Topography Mission.

The EarthKAM, a digital camera mounted at an overhead window on Endeavour's flight deck, continues its record setting pace. A little after 5 a.m. EST Saturday flight controllers reported it had sent down more than 2,018 images, the combined total of the four previous flights on which it had flown. The camera takes pictures for middle school students. Through the Internet, their schools' mission operations centers are linked to the EarthKAM Mission Operations Center at the University of California at San Diego. Except for setup, initial camera pointing and lens changes, no crew involvement is required for normal operations.

February 18, 2000 - Mission managers late this afternoon announced a nine-hour extension to the data-taking portion of the mission. That means that mapping of the Earth now will continue until about 7 a.m. EST Monday. Science operations continued smoothly through the mission's eighth day, with all radar and support hardware continuing to work better than hoped. "Everything is perfect. It's incredible," observed Marian Werner, X-SAR project manager for the German Aerospace Agency, which provided the X-band radar system used by SRTM.

February 17, 2000 - Propellant conservation measures have paid off and Endeavour's crew was notified this morning that the mapping operations will continue for the full nine days as planned prior to launch. Astronaut Chris Hadfield in Mission Control transmitted the good news to the crew aboard Endeavour while all six astronauts were awake conducting a shift change. The crew is working around the clock on two shifts conducting the detailed mapping operations. Several fuel-saving steps have been implemented, including a change in the way excess water is dumped overboard, and allowing more flexibility in holding Endeavour and the 200-foot mast in the proper attitude. The final conservation measure will be the deletion of the eighth trim burn, which controllers believe can safely be deleted by adjusting the sixth and seventh burns without a disruption to data collection.

Science operations continued through the seventh day of the mission, with trouble-shooting a problem with one of six high data-rate recorders on board being the only issue of significance. The recorders are used to capture the masses of data collected during the SRTM mission on 270 tapes. Meanwhile, EarthKam continues its record-breaking production of images, having processed 1,355 images.

February 16, 2000 - With growing confidence that fuel-saving measures onboard Endeavour will permit the radar mapping mission of more than 70 percent of the Earth's surface to run its full duration, flight controllers and crew members today marked the mission's mid-way point. Mission Control also told the astronauts that the EarthKAM aboard Endeavour has successfully transmitted its 1,000th image for middle school students. EarthKAM, mounted in the overhead starboard window of Endeavour's aft flight deck, lets middle school students take pictures of the Earth. They use interactive web pages to select photos. On four previous flights, EarthKAM took more than 2,000 photos.

February 15, 2000 - 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.

February 14, 2000 - Operations onboard Endeavour continued without interruption, even without the availability of a small nitrogen thruster on the end of the extended boom. Both radar systems -- C-band and X-band -- continue to perform flawlessly. Endeavour crewmembers successfully completed their second "flycast maneuver" trim burn early Monday, as the spacecraft continued to gather data that will greatly improve our topographical knowledge of the Earth's surface. Scientists already have expressed delight with low-resolution "quick look" data, which revealed features not shown on today's best maps. By midday, about 24 million square miles had been mapped once, and 9 million square miles twice. After only three days of flight, the mission has tripled the world's supply of digital terrain elevation data.

The flycast maneuver reduces stress on the almost-200-foot mast extending from Endeavour's cargo bay. The orbiter flies tail-first during mapping operations. For the maneuver, it was moved to a nose-first attitude with the mast extending upward. A brief reaction control system pulse began the maneuver. The mast rebounded forward after a slight deflection backwards. As it straightened, a stronger thrust stopped its motion while increasing the orbiter's speed.

February 13, 2000 - The Shuttle Radar Topography Mission's mapping operation continues to run smoothly, with about 17.7 million square miles of the Earth's surface having been mapped by 7 p.m. Central time. Scientists also reported that 38 percent of landmasses had been mapped thus far in the flight. Despite a problem with a small nitrogen thruster on the end of the 200-foot-long mast, both the C-band and X-band radars continue to perform as expected, and the thruster problem has had no impact on mapping operations.

Endeavour's crew and flight controllers continue troubleshooting a problem with a small nitrogen thruster mounted at the tip of the radar's outboard antenna. Although gaseous nitrogen propellant is flowing, little or no thrust is being produced. Crew members cycled the valve open and closed in an attempt to pinpoint the problem. Controllers plan to leave the valve closed for several hours to attempt to quantify the rate of propellant usage. The thruster was designed to keep the mast from "righting" itself in response to Earth's gravity and remove the need for additional orbiter thruster firings to keep the antenna in its data-taking position. Without the thruster on the antenna, crew members have to fire the orbiter's thrusters more than expected.

February 12, 2000 - Endeavour astronauts began mapping operations on the Shuttle Radar Topography Mission, which will provide maps of the Earth unprecedented in accuracy and uniformity. 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.

Blue Team members Dom Gorie, Janice Voss and Mamoru Mohri began the first mapping swath, covering a 140-mile-wide path, at about 12:31 a.m. Saturday. 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.

By the time members of Endeavour's Red Team had reached lunchtime on this first full day in space for the Shuttle Radar Topography Mission, the radar antennas in the payload bay and at the end of a 200-foot mast had mapped about 1.7 million square miles (4.5 million square kilometers) of the Earth's surface, or the equivalent of about half the area of the United States.

The first X-band image ­ of the area near White Sands, New Mexico ­ was released this afternoon, and scientists expressed their delight with the quality of the image. X-band images will be posted to the German Space Agency web site at www.dfd.dlr.de/srtm/html/newtoday_en.htm. Both the C-band and X-band radars continue to perform as expected.

February 11, 2000 - With six astronauts on board, Endeavour sped to orbit under cloudless skies from the Kennedy Space Center today to begin the Shuttle Radar Topography Mission, the first human space flight of the 21st century.

The STS-99 crew's first tasks were to set up Endeavour for dual shift, round-the-clock operations using a trio of radar systems mounted in the cargo bay for the most comprehensive three-dimensional map of the Earth ever attempted. Red Team leader Commander Kevin Kregel, and colleagues Janet Kavandi and Gerhard Thiele initiated extension of the radar mast at 6:27 p.m. EST. After 17 minutes, all 87 cube-shaped bays of the carbon fiber-reinforced plastic, stainless steel, alpha titanium, and Invar structure were deployed by 6:44 p.m. Total length of the mast was 60.95 meters, or just under 200 feet.

As the Red Team performed the checkout procedures, Blue Team members Dom Gorie, Janice Voss and Mamoru Mohri set up the shuttle's network of portable computers and began an abbreviated six-hour sleep period at 4:44 p.m. They'll be awakened at 10:44 p.m. to begin radar mapping operations late tonight. Endeavour is orbiting the Earth in an orbit inclined 57 degrees to either side of the Equator for the radar mapping of around 80 per cent of the Earth's surface.

Overview - The Shuttle Radar Topography Mission (SRTM) is an international project spearheaded by the National Imagery and Mapping Agency and NASA, with participation of the German Aerospace Center DLR. Its objective is to obtain the most complete high-resolution digital topographic database of the Earth. SRTM consists of a specially modified radar system that will fly onboard the space shuttle during its 11-day mission. This radar system will gather data that will produce unrivaled 3-D images of the Earth's surface.

SRTM uses C-band and X-band interferometric synthetic aperture radars (IFSARs) to acquire topographic data of Earth's land mass (between 600N and 560S). It produces digital topographic map products which meet Interferometric Terrain Height Data (ITHD)-2 specifications (30 meter x 30 meter spatial sampling with 16 meter absolute vertical height accuracy, 10 meter relative vertical height accuracy and 20 meter absolute horizontal circular accuracy).

The result of the Shuttle Radar Topography Mission could be close to 1 trillion measurements of the Earth's topography. Besides contributing to the production of better maps, these measurements could lead to improved water drainage modeling, more realistic flight simulators, better locations for cell phone towers, and enhanced navigation safety.