Still No Signal from Frozen Mars Lander

NASA is once again listening for any signs that its Phoenix Mars Lander has resurrected itself after the long Martian winter, but so far, the frozen lander has remained silent.

The space agency is using its Mars Odyssey orbiter to scan for any beeps of life Phoenix may send in the off-chance it has survived the red planet?s winter. The listening campaign is NASA?s second for Phoenix and slated to last about a week.

Phoenix landed on Mars on May 25, 2008, and operated successfully in the Martian arctic for about two months longer than its planned three-month mission to dig for buried water ice on Mars near the planet?s north pole.

But once the sun and temperatures dropped and winter set in, the spacecraft didn't have enough power to keep going. The lander went silent in November 2008.

Phoenix's landing site is now in mid-springtime, and the sun is above the horizon for about 22 hours each Martian day (a Martian day is 40 minutes longer than an Earth day). The amount of light falling on Phoenix is about the same as the spacecraft experienced a few weeks after the completion of its three-month primary mission.

Phoenix was not designed to withstand the extremely low temperatures and the ice load of the Martian arctic winter. But in the extremely unlikely event that the lander has survived the winter and has enough energy, it would operate in a mode where it periodically wakes itself up and transmits a signal to any orbiter in view.

Odyssey conducted its first listen for signs of life from Phoenix in January. This second attempt began on Feb. 22 and will continue through Feb. 26 with 50 flights over the Phoenix site. A third campaign to check on whether Phoenix has revived itself is scheduled for April 5-9, when the sun will be continuously above the Martian horizon at the Phoenix site.

• Images: Phoenix on Mars
• Odds Slim for Resurrecting Defunct Mars Lander
• Special Report: Highlights of the Phoenix Mars Lander Mission