Scientists Unveil New Images Of Earth From Space Shuttle Mapping Mission

STS-99 Mission Status Report #10 -- Feb. 15, 2000

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.

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STS-99 Mission Status Report #9 -- Feb. 15, 2000

Endeavour astronauts had completed mapping well over half the targeted Earth land surface by early Tuesday, and scientists continued to express delight at the quality of information they were seeing.

More than 20 percent of the targeted land had been mapped twice and the Shuttle Radar Topography Mission had covered more than 6 percent of it three times. The area surveyed at least once was equal to that of Africa, North America and Australia combined.

Those totals were growing rapidly. Endeavour was gathering mapping data on 40,000 square miles of land each minute. Scientists say the mission already has tripled the world’s pool of digital terrain data with this much detail.

Endeavour is gathering data four times faster than its advanced data communications system can send it to Earth. “Quick look” data sent down, with less detail than will be available from the high-density tapes being filled aboard the orbiter, already has revealed features not shown on even the best maps available today.

While Endeavour continued to gather data that will be the basis for maps of unprecedented accuracy and uniformity, flight controllers were troubleshooting the balky cold-gas jet on the outboard antenna structure. The jet helps maintain the attitude of the mast – the longest rigid structure ever deployed in space. The orbiter’s reaction control system jets are being used for that function. Flight controllers are developing further procedures to conserve propellant.

Blue Team members Pilot Dom Gorie and Mission Specialists Janice Voss and Mamoru Mohri sent down television early Tuesday. It showed Voss using an inflatable globe to explain the SRTM mission, Mamoru Mohri, taking photos out the commander’s window, and then, with Pilot Dom Gorie, changing a tape on a payload high rate recorder.

Members of the Red Team, Commander Kevin Kregel, and Mission Specialists Janet Kavandi and Gerhard Thiele, are in their sleep period. They are scheduled to be awakened at 10:14 a.m. Central Standard Time.

Endeavour’s systems are functioning normally as it circles the Earth at a speed of about 5 miles a second and an altitude of about 150 miles.

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STS-99 Mission Status Report #8 -- Feb. 14, 2000

“As excited as a kid on Christmas day” is how Shuttle Radar Topography Mission project engineer Ed Caro described his reaction to the progress of the radar-mapping mission thus far. Operations onboard Endeavour continued without interruption, even without the availability of a small nitrogen thruster on the end of the extended boom. By midday, about 24 million square miles had been mapped once, and 9 million square miles twice. That’s more than half the planned coverage for the mission.

Mission scientists continue to express delight with the “quick-look” data seen so far. SRTM project scientist Dr. Michael Kobrick notes that Endeavour is mapping 100,000 square kilometers every minute, and that after only three days of flight, the mission has tripled the world’s supply of digital terrain elevation data. The low-resolution images processed so far show many topographic features that until now have been difficult to detect on the best maps in existence today.

A continuing problem with a small nitrogen thruster on the end of the 200-foot-long mast has had no impact on mapping operations or data quality. Both radar systems -- C-band and X-band -- continue to perform flawlessly. Flight controllers are continuing to troubleshoot the problem with the thruster, which helps control the mast’s attitude. This function currently is being performed by Endeavour’s reaction control system. Mission managers are implementing propellant conservation measures and hope to meet the full nine-day science objective. The mast continues to provide an extremely stable platform for the mapping operations.

As their workday concluded, Blue Team members Dom Gorie, Janice Voss and Mamoru Mohri spent a few minutes on Endeavour’s flight deck discussing various mission activities. The Blue Team turned in shortly after 2 p.m., with a wake-up call set for 10:14 tonight. The Red Team’s Kevin Kregel, Janet Kavandi and Gerhard Thiele were awakened a few minutes after 10 a.m. to continue mapping operations.

As of this morning, 525 images had been taken by students using the EarthKam, which allows photos of Earth to be taken using a camera on the shuttle. So far, 20 of the 84 schools participating in the program have requested and received photos.

All of Endeavour’s systems are functioning normally as it circles the Earth every 90 minutes at an altitude of about 150 miles.

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STS-99 Mission Status Report #7 -- Feb. 14, 2000

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 early Monday morning, about 20 million square miles had been imaged. By the planned end of the mission, more than 45 million square miles will have been imaged twice.

Processing of the huge amount of data gathered by Endeavour – enough to fill about 13,500 CDs if all goes according to plan – will result in maps 30 times more accurate than the best global data available now. The maps also will be of unprecedented uniformity.

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.

Endeavour is in a low orbit, and is slowed by the upper atmosphere. The crewmembers make daily flycast maneuver trim burns to keep the spacecraft in the proper altitude for mapping.

Flight controllers and crewmembers are troubleshooting a cold gas jet, a thruster on the SRTM outboard antenna. The jet is designed to help control the mast’s attitude, a function now being performed by Endeavour’s reaction control system jets. The mapping mission continued uninterrupted as flight controllers worked to develop propellant-conserving strategies.

Members of the Blue Team, Pilot Dom Gorie and Mission Specialists Janice Voss and Mamoru Mohri, continued to manage the Payload High Rate Recorders, changing the high-density tapes that will return the mapping data to Earth. About 270 of those tapes are expected to be filled.