08/24/93

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Stanford experiment among the missing somewhere near Mars

STANFORD -- A Stanford experiment is one of seven that may be lost if NASA cannot restore communications with the Mars Observer spacecraft.

Communication with the $900 million craft was lost Saturday, Aug. 21, when an on-board radio transmitter failed to turn on. Ground controllers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena have been trying to restore communication.

The spacecraft was supposed to go into orbit of Mars Tuesday afternoon, but without communications, controllers may not know whether it did so, or whether it sailed by the planet and is lost in space forever. Either way, Mars Observer would be a total failure.

(Late Tuesday afternoon, Aug. 24, controllers hoped to contact the spacecraft after it achieved orbit - if it did. "We have negative on a signal," one of the controllers said when nothing was heard.)

"I'm disappointed and saddened by the failure," said Von R. Eshleman, professor of engineering who helped design the radioscience experiment. Eshleman said he had no more information on what was wrong with Mars Observer than did anyone else.

The Stanford crew, headed by G. Leonard Tyler of Stanford's STAR Lab, was in Pasadena waiting to see if contact could be reestablished. They had been working on Mars Observer for more than five years.

The experiment on board the unmanned spaceship was to use radio occultation techniques perfected during the explorations of Saturn, Neptune and Jupiter to take the temperature, measure the pressure, and help plot the gravitation of the planet. The Stanford scientists are particularly interested in the polar regions.

The researchers were to gather a full year's data from an orbit that would eventually be lowered to an average altitude of 235 miles (378 kilometers) above the surface to see how the Martian seasons change.

While the Stanford team was to collect the radioscience data, other experiments were to survey other aspects of the planet, gathering far more data than had ever been collected of the Red Planet.

Eshleman believes the techniques used to survey Mars also could apply to surveying Earth, giving a baseline for accurate measurements of the environment possible no other way.

Eventually, the orbiting Mars Observer also was to be used to relay data from a French atmospheric balloon and a Russian Mars lander. Both those experiments could still work without the help of Mars Observer, but not as well.

Officials at JPL said they did not know what was wrong with the spaceship, thinking at first that the internal clock that ran the computer- controlled operation had failed. They later came to think the trouble might be with the computer itself.

They tried to simulate the problem with an exact model in a JPL laboratory and to think up "workarounds" to solve it, but to no avail.

The Mars Observer is the latest in mishaps to befall the troubled space agency. Galileo, the spacecraft heading to Jupiter, has operated with diminished efficiency; the Hubble space telescope needs a repair job in space; the most recently scheduled space shuttle mission has now been postponed three times (the latest within three seconds of lift-off), and plans for the space station have been forced to be completely revamped by the Clinton Administration.

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