NASA gives thumbs up to extend shuttle mapping mission

View of the radar mast extending from the shuttle cargo bay

February 18, 2000
Web posted at: 9:09 p.m. EST (0209 GMT)

In this story: Crew saves fuel, fixes data glitch Alaska-sized area mapped every 15 minutes Grade school project sets record pace RELATED STORIES, SITES

From staff reports

JOHNSON SPACE CENTER, Texas (CNN) -- NASA will continue the mapping mission of the space shuttle Endeavour now that enough fuel has been saved to compensate for a broken thruster, space agency engineers said Friday.

The proposed nine-hour extension could leave the crew without sufficient time to make an emergency spacewalk, should one be needed, to hoist the shuttle's long radar mast into the cargo bay. However, it will not affect Tuesday's scheduled landing.

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Mission engineers were attempting to "squeeze more science time," NASA shuttle manager Milt Heflin told reporters in Houston. "Any additional hour we can get is more science data for us."

The segments of the 197-foot (60-meter) radar mast are designed to collapse like soup cans when the crew wraps up their mapping work. But if the mission extends beyond Sunday evening and the mast does not retract properly, the crew probably will have to jettison it into space before landing.

"It would be nice to bring the mast back and fly it again in a few years," said mission specialist Janet Kavandi during a news conference earlier Friday.

A second mapping mission could check changes in plate tectonics, which could help scientists predict earthquakes, she said.

Crew saves fuel, fixes data glitch

After scrimping on fuel to compensate for the faulty thruster, the crew on Thursday corrected a problem with a machine used to record Earth map data.

There was "a small blip in some of the information" being stored by one of six high-data rate recorders, said NASA spokesman Doug Peterson in Houston on Friday. "People down here asked the crew to swap out some cable. They did that and it's working fine again."

The malfunctioning gas valve had threatened to cut short the mission by as much as a day.

A leak or clog in a tiny gas valve on the tip of the shuttle's radar antenna mast was forcing astronauts to fire the shuttle's thrusters more often to steady the mast.

But some unusual fuel saving measures paid off and mission controllers told the crew Thursday that mapping operations would proceed for nine days as planned.

Adding to their good fortune, mission engineers on Thursday observed that the small nitrogen gas jet on the mast seemed to have begun providing some thrust.

Endeavour performed its sixth "flycast" engine firing Friday morning. The complicated maneuver maintains the shuttle's altitude at around 150 miles (240 kilometers), necessary for the crew's precise mapping data collection.

The daily firing boosted the shuttle higher than normal this time, a deliberate change that should save fuel by eliminating an engine burn scheduled for Sunday, NASA controllers said.

Besides modifying the shuttle's engine burns, other fuel saving measures include flushing waste water instead of vaporizing it and restricting the use of certain equipment.

SRTM image of Kamchatka, a Russian peninsula comparable in size to Japan

The Endeavour is to make images of 70 percent of the Earth's land forms at least twice, providing information to produce the most comprehensive and detailed three-dimensional maps of the world.

By Friday morning, more than 24 million square miles (39 million square kilometers) had been mapped with two or more passes, representing more than 50 percent of the target area.

The shuttle's radar system has mapped almost 40 million square miles (64 million square kilometers) at least once. That area is larger than the Americas, Africa and Australia combined.

Endeavour's radar system was scanning an area the size of Alaska every 15 minutes.

NASA said an experiment on the shuttle inspired by children has set a record pace.

The EarthKAM camera has already beamed back almost 1,400 photos of Earth to middle school students. On four previous shuttle flights combined, EarthKAM sent down some 2,000 photos.

The shuttle is scheduled to land at Cape Canaveral on Tuesday.