NASA sends 'please wake up' call to Phoenix lander

— -- NASA engineers still hope to rouse a slumbering Phoenix lander and wring the last science out of the mission to Mars' North Pole.

The solar-powered craft landed in May, enjoying around-the-clock sunshine during the Martian summer. Now facing winter, the lander receives eight fewer hours of recharging sunlight each day.

An unexpected dust storm last week further cut sunlight during a high-energy work day, coming at the "worst time," says project chief Barry Goldstein of NASA's Jet Propulsion Laboratory in Pasadena, Calif. The storm caught the lander when its batteries were most depleted and cut communications for two days. Goldstein compared the spacecraft to a laptop computer with low batteries that forces itself to shut down as soon as it starts up, further draining its batteries.

"Nothing we can do can fight the environment," Goldstein says. But "by the end of the week, I'm hopeful we can resume science," he says, since the dust storm has lightened enough for the lander to communicate daily with mission controllers.

The mission is two months past its original three-month planned lifetime of chemically analyzing ice frozen in the Martian Arctic. In July, the lander confirmed that ice is in the soil; it later saw the first snowfall spotted on Mars.

"We're very happy we completed the primary mission. Anything beyond that time was a bonus," says mission scientist Ray Arvidson of Washington University in St. Louis. If the mission continues, the lander will act as a weather station, transmitting meteorological details from the ground as the Mars northern plains ice over. "We have snow, we have ice, we have dust storms. There is a lot of exciting weather going on right now there," Arvidson says.

The next step is sending power-saving instructions before the lander's batteries go completely, which Goldstein gives 50-50 odds of success.