Since human eyes first turned skyward, Mars has been a distant red object of desire that, more than any other outworld, exerts a tidal pull on the imagination.
Long the focus of hopes for alien life in the universe, it has been haunted for generations by speculative and scientific phantoms--canals, vegetation, ice-eating crystophages, even faces and pyramids.
More recently, the voyages of the Mariner, Viking, Pathfinder and Global Surveyor spacecraft galvanized global attention and revealed a planet that may once have harbored primordial microbes but is now an eerie place of dunes, dust devils, dry ice, dead volcanoes and subzero winds. Blue clouds adorn its salmon pink sky and strange magnetic stripes its soil.
Under such scrutiny, the prospect of life on Mars has receded ever further into the planet's past, and the search for clues focuses ever deeper beneath the planet's sterile surface.
This week, that pursuit will bring 100 scientists from five countries to UCLA and the Jet Propulsion Laboratory with their hopes pinned on a spindly robot called the Mars Polar Lander.
The stakes are heightened even more than usual by the loss, caused in September by a navigation error, of the $125-million Mars Climate Orbiter and by problems uncovered in the Polar Lander by the investigation into that failure.
As the craft bears in on Mars at 10,870 miles per hour, JPL engineers are working to correct those technical problems, which could jeopardize its mission. JPL managers added 37 senior engineers and navigators to the task and spent an extra $2 million in additional readiness reviews and systems tests.
If all goes well, the $165-million lander is expected to touch down near the Martian south pole on Friday after a journey of 470 million miles. For 90 days, it will seek evidence of water and other data to help scientists understand the ancient climate on Mars and, by inference, its suitability--once upon a time--for life.
The Polar Lander will be the first craft to explore the south polar icecap and the first to carry a microphone to relay the sounds of another world. But first it has to negotiate a complex landing maneuver on the heels of the Climate Orbiter loss.
"We are always really, really nervous at this point in a mission, but the nervousness has increased a lot more," said Louis Friedman, executive director of the Planetary Society, which is sponsoring the microphone experiment. "So much is at stake for the Mars program, for NASA and for JPL."
