Red planet lander may soon fade to black

The death watch is on for NASA's Phoenix lander, the first spacecraft to sample water on another planet.

Buffeted by dust storms and chilled by temperatures as low as 141 degrees below zero from the arrival of the Martian winter, Phoenix is clinging to life, but barely, NASA officials said Friday.

“We knew this was coming,” said project manager Barry Goldstein. “It's bittersweet.”

Earlier this week, Phoenix fell silent, going into safe mode to save battery power. After failing to answer to two wake-up calls from Earth, it flickered back to life long enough Thursday to send a signal to the Mars Odyssey spacecraft orbiting overhead. It then went back to sleep for another 19 hours to recharge its batteries.

The lander, however, failed to awaken from its latest sleep Friday, alerting NASA officials to the possibility that the end may be soon.

He said mission officials will keep watch over the weekend to see if it revives again.

Phoenix, which landed May 25, has survived two months longer than its planned three-month mission. But with the sun sinking lower in the northern sky, the solar panels that power the craft's instruments can't draw as much power. A dust storm this week also applied a fine coat of Martian soil to the solar panels, further limiting their ability to produce electricity.