Hopes of recovering spacecraft are slim, NASA official says

Contour, sent to study comets, fell silent Aug. 15

August 24, 2002|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

The director of NASA's $159 million Contour mission says there is no more than a "one in 10,000" chance that his team will recover the spacecraft, which went silent Aug. 15, six weeks into a four-year journey to study comets.

Controllers at the Johns Hopkins Applied Physics Laboratory near Laurel lost contact with the spacecraft soon after it fired its solid-fuel motor last week to rocket out of Earth orbit toward an encounter with Comet Encke planned for next year.

Misson Director Robert W. Farquhar said the spacecraft's motor apparently worked perfectly for 48 seconds of the planned 50-second burn.

Then "something went horribly wrong in the last two seconds," he said. "It's got something to do with the motor firing. But we don't know if it was the motor or something else."

Farquhar said the chances of recovering the spacecraft are now "pretty damn small, not better than one in 10,000."

Controllers have heard nothing from the spacecraft since it left Earth orbit. Radio signals that Contour was programmed to send if it had no instructions from Earth for 96 hours have not been detected.

Astronomers have snapped photographs of three bright objects streaking away from Earth. Their trajectory leaves little doubt that they are whatever remains of Contour. "It's following the path we put it on," Farquhar said. "What else is out there?"

The objects are now more than a million miles from Earth, moving 3 percent slower than Contour's planned speed. That corresponds to a 48-second engine burn, instead of 50, Farquhar said.

The telescopic images don't reveal what's left of Contour. "Obviously, the brightest piece we think is the spacecraft itself," he said. "The hope is that the other pieces are very bright objects, maybe the [rocket] nozzle and some insulation floating around," but nothing vital.

The fear is that Contour blew itself apart and is a constellation of space junk.

Before the final engine burn, Farquhar said, Contour performed 23 complex maneuvers perfectly. "The operation was a success," he said. "Only the patient died."

The National Aeronautics and Space Administration is preparing for an independent investigation into the cause of Contour's failure. The makeup of the Contour Mishap Investigation Board is expected to be announced as early as next week. Controllers at APL will listen for Contour's signal again in mid-December, when its orbit around the sun would bring its antennas around to a more favorable position for contacting Earth.

If the spacecraft is contacted and found to be functioning, Farquhar said, there will be time to steer it toward an encounter with Comet Encke.

"As long as I can make a [course] correction, at the latest in early January," he said, "I can still recover the mission." Later than that, Contour would be too far off course.

Such a recovery is a long shot, and Farquhar said members of his team are heartsick. Many have worked on Contour since before it won NASA funding in 1997 and hoped to stay with it through its comet flybys next year, in 2006 and possibly beyond. "They're pretty depressed," he said.

Farquhar, 69, said he has refocused on new missions. He is directing APL's Messenger mission to Mercury, now in development, and hopes to lead an APL-designed mission to send a craft to Pluto by 2015.

"When you're trying to do things that have never been done by anybody before, sometimes you're not going to succeed," he said. "But that doesn't mean you shouldn't keep trying."

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