Mars craft prompts 'desperate measures'

Published Dec 5, 1999

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Andrew Quinn

Pasadena, California - Scientists struggling to contact the Mars Polar Lander pinned their hopes on a brief, 10-minute communications window on Sunday but said if that failed "more desperate measures" would be considered.

Sunday's opportunity begins at 10.50am PST (1.50pm EST/1850 GMT), and will mark the fifth time that Nasa project managers in Pasadena have tried to reach the $165-million (R990-million) spacecraft since its scheduled landing near Mars's south pole on Friday.

The attempt, which will try to use the lander's UHF antenna for the first time to relay signals through the orbiting Mars Global Surveyor satellite, comes as the silence from the Mars Polar Lander becomes increasingly ominous.

"If that doesn't bring us answers, then we really do have to start looking at more desperate measures," said David Crisp, a senior project scientist at Nasa's Jet Propulsion Laboratory.

The UHF transmitter is intended as a backup system and could be functioning if the craft's main antenna is damaged or pointing in the wrong direction because of a bad landing.

Scientists say the UHF communications system has several strengths, sending relatively strong signals just a short distance up to the satellite. But it is contingent on the lander not being in so-called "safe mode", a protective sleep triggered by a problem encountered during touchdown.

If this communications attempt proves fruitless, project managers will begin bombarding the craft with commands to switch to various back-up systems in the event that pieces of its hardware were damaged.

"Everybody has a belief that we can still get a signal from the spacecraft," said Richard Cook, project manager at JPL, noting that another attempt to link up with the lander was set for Sunday evening.

"As time goes by, I'm not going to tell you different, we're less confident."

Confidence was also clearly beginning to wane on the fate of two grapefruit-size Deep Space probes, which were supposed to detach from the craft and hurtle themselves into the Martian soil at 640kph on Friday.

The probes, dubbed Amundsen and Scott after the first explorers to reach Earth's South Pole, were supposed to have made contact through the Mars Global Surveyor several hours after impact.

But like the lander, they have remained stubbornly silent, and project scientists conceded that their short battery lives made it imperative that they begin relaying data soon.

"We're going to continue to try to contact the probes every two hours for the next two days," said Sarah Gavit, project manager for the probe project.

The repeated failure to contact either the lander or the probes threw a pall of gloom over the fate of Nasa's latest Mars mission, its first trip back to the red planet since the $125-million Mars Climate Orbiter was lost in September due to human miscalculations.

With a series of Mars projects planned for the next decade, Nasa administrators in Pasadena were thrown on the defensive about their "faster, better, cheaper" strategy for exploring the solar system.

"I'm not even prepared to spend any time even thinking about the possibility that we've lost a second mission," said Carl Pilcher, Nasa's science director for solar system exploration, as reporters peppered him with questions about the feared loss of the lander.

"If we need to worry, there's going to be plenty of time to worry and replan," he said.

The Mars Polar Lander, which was launched in January, was designed to search the south pole region of Mars for signs of water ice and clues about the planet's climate past and present.

Ultimately, scientists hope to learn whether life ever existed on Mars or, if in future, manned missions there could harvest natural resources to help them survive its harsh environment 232 million kilometres from Earth. - Reuters

- Sapa-Ap reports that Nasa's Jet Propulsion Lab's home page has links to the latest Mars projects as well as probes sent to other planets over the last 20 years.

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