Missing The Mark A Navigation Error Erases A Multimillion-Dollar Attempt To Study Mars

A “huge” navigation error of almost 60 miles probably sent a Mars-bound NASA satellite, a $125 million piece of a $327 million project, plunging to a fiery death early Thursday morning in the very atmosphere it was supposed to study.

The presumed loss of the Mars Climate Orbiter is the latest in a painful series of recent setbacks for NASA. The agency was already reeling from the grounding of its space shuttle fleet due to faulty wiring, congressional efforts to cut $1 billion from its budget and continuing problems with its overbudget international space station.

“I felt slugged this morning when I heard it,” said Donna Shirley, the NASA manager who approved the project.

NASA officials said their hopes for a detailed picture of the Martian climate are not lost with the probe. The agency is in the midst of a 10-year, 10-probe scientific assault on the Red Planet. Experiments scheduled for the Mars Climate Orbiter will be put on future flights.

Yet NASA was decidedly red-faced Thursday, not just because of the loss of the probe, but because of the way it appears to have been lost - the worst navigation error in more than 30 years.

Engineers thought all was well when the probe fired its engine early Thursday in a maneuver designed to place it 93 miles above the planet in the first of what was to be hundreds of orbits. But the spacecraft disappeared behind Mars and was not heard from again.

That’s because the probe was not where NASA thought it was, project manager Richard Cook said. The probe actually dropped to an altitude of 37 miles - so low that it probably caught fire from atmospheric friction and was destroyed.

NASA is trying to figure out how the Mars Climate Orbiter could have been so far off course. Experts are astounded because the mistake is so big and navigation is a task the agency’s Jet Propulsion Laboratory prides itself on.

“Navigation is our strong point,” said Shirley, NASA’s former Mars program manager and now assistant dean of engineering at the University of Oklahoma. Missing its mark by about 60 miles “is a huge miss. They’re down to one kilometer (six-tenths of a mile) or less accuracy routinely. We’re the best navigators in the world.”

Arizona State University astronomer Ron Greeley, who has worked on several Mars missions, said, “Everybody’s scratching their heads over this one … because it’s so hard to explain. It almost makes one think that a decimal point was slipped.”

Development project manager John McNamee indicated that software or human error probably was to blame. A team of experts inside and outside NASA is assessing what went wrong and how future missions can be protected, said Carl Pilcher, science director for solar exploration.

But anytime NASA tries to leave Earth, risk is involved, engineers emphasized.

“This isn’t a trip to grandma’s,” said Ed Weiler, NASA’s associate administrator in charge of space science. “This is tough stuff and there will be failures.”

“The real strength of our Mars program is that it is robust to failure,” said Cornell University astronomer Steve Squyres, who headed NASA’s long-range martian mission planning committee. “It’s a big loss, but I think it’s one that we can sustain.”

The probe’s first mission was to provide direct communication between Earth and the Mars Polar Lander, which arrives in December. But another Martian satellite and the Polar Lander itself can do the job with only slight degradation in data, Pilcher said.