No Sign of Mars Lander Found in Radio Signals

Astronomers who spent the weekend sifting through radio transmissions from space say they have detected no signals from the missing Mars Polar Lander.

But project leaders said Monday that they are still trying to contact the craft and have turned to astronomers worldwide for help. Scientists say that if the lander is still operational, they would not expect a signal back before Friday, and a clear indication might not come for several more days.

The $165-million craft was lost Dec. 3 as it plummeted into the Martian atmosphere, and was officially declared lost by NASA on Jan. 17.

But Jet Propulsion Laboratory scientists restarted efforts to find the craft last week after Stanford radio astronomers detected a weak signal coming from the direction of Mars. The UHF signal, they said, might have been from the lander, or may have been a stray signal from a television station or other Earth source.

“We still don’t know” if those transmissions were from the lander, said Sam W. Thurman, the mission’s flight operations manager. “We’re still continuing to search more carefully.”

Today and Wednesday, mission engineers will send commands to the lander ordering it to recalibrate its clock and send signals back to Earth. If they come, those signals are expected to reach Earth on Friday, when radio telescopes in the Netherlands, England and Italy have promised to listen in.

The international cooperation, said project manager Richard Cook, “shows that Mars is something that captivates everyone’s imagination.”

The Stanford astronomers who heard the first signal are continuing to process the radio transmissions they have and say it is possible that a more detailed analysis could reveal a signal although that could take days or weeks.

“Would I like to hear from it? Sure,” Thurman said. “But I have no meaningful way to assess the likelihood of that happening.”

NASA officials are still investigating the loss of the lander to determine the fate of the next mission to Mars, which was scheduled for 2001.