Mars orbiter presumed gone for good

Mars orbiter presumed gone for good

By MATTHEW FORDAHL

PASADENA, Calif. (September 23, 1999 12:55 p.m. EDT http://www.nandotimes.com) - A $125 million spacecraft meant to be NASA's first interplanetary weather satellite was presumed destroyed Thursday after it failed to regain contact with Earth following a critical engine firing to place it in orbit around Mars.

A preliminary analysis shows the Mars Climate Orbiter approached Mars too closely and likely broke into pieces or burned up in the atmosphere, said operations project manager Richard Cook of NASA's Jet Propulsion Laboratory.

The problem likely stemmed from human or software error, not a mechanical problem with the spacecraft, he said. The cause is being investigated.

The orbiter was believed to have come within 37 miles of Mars' surface at about 2 a.m., just as the probe's main engines were firing for orbit insertion. The lowest survivable close encounter is believed to be 53 miles, Cook said.

"We believe the spacecraft came in at a lower altitude than we predicted," he said. "Depending on how low that was, it could be the total loss of the mission."

Until final altitude numbers become available, the giant antennas of NASA's Deep Space Network were scanning the skies in search of a signal from the probe.

Officials said the loss will not hurt the space program in the long run.

"We intend this to be a case of science delayed, not science lost," said Carl Pilcher, of NASA's Office of Space Science.

The orbiter, one of two probes scheduled to arrive at the red planet this year to study the weather and search for evidence of water, should have regained contact with Earth at 2:26 a.m.

The probe was behind the planet and out of radio contact during most of the 17-minute engine firing that should have placed it in orbit. Contact should have been established by 2:30 a.m. at the latest.

The orbiter and its companion, the Mars Polar Lander, carried instruments designed to discover the fate of water believed to have once formed rivers or lakes on the planet. Mission scientists say water is the key to determining whether life ever existed on Mars.

The separately launched lander, due to arrive Dec. 3, was supposed to use the orbiter as a communications relay. But the lander also can communicate directly with Earth, and the already orbiting Mars Global Surveyor can act as a limited relay as well.

Both probes are part of a $327.5 million mission collectively known as Mars Surveyor '98, NASA's latest in a series of relatively inexpensive robot probes. The orbiter rocketed into space last Dec. 11 and its sibling probe was launched Jan. 3.

In 1997, Mars Pathfinder and its rover, Sojourner, explored the geology of the planet and found some evidence that water may once have flowed. The Mars Global Surveyor, which arrived later that year, mapped the surface and found more signs of once-flowing water.