LOS ANGELES
(AP) — NASA's Phoenix Mars spacecraft regained contact with Earth more than a
day after falling silent, but its days operating on the red planet are still
numbered, mission managers said Thursday.
Waning
sunlight and a dust storm this week drained the lander's power, forcing it to
go into safe mode. It failed to respond to two wake-up calls from Earth but
sent a signal late Thursday when the orbiting Odyssey spacecraft passed
overhead.
Phoenix is programmed with a "Lazarus
mode" that automatically causes it to reboot itself after losing power.
Though Phoenix answered the latest call, it went back to sleep for another 19
hours to recharge its battery. Engineers expect the lander to survive several
more weeks.
"We
knew this was coming. It's bittersweet," said project manager Barry
Goldstein of NASA's Jet Propulsion Laboratory.
Phoenix landed in the Martian arctic in
May. During its three-month prime mission, the sun stayed above the horizon,
allowing the long-armed lander to dig trenches in the soil and collect ice bits
for its various instruments to analyze.
NASA
extended the mission in hopes of getting the most science out of the spacecraft
before it dies.
In recent
days, the weather at Phoenix's landing site has worsened. Overnight
temperatures plunged to minus 141 degrees, and daytime temperatures reached
only minus 50 â€" the lowest temperatures so far in the mission. The lander
also weathered a dust storm.
Phoenix landed in a patch of ice in Mars'
high northern latitudes to study whether the environment could be friendly to
microbial life. It has found evidence that the ice may have melted at some
point, although the soil is dry. It has yet to find the presence of organic, or
carbon-based, compounds that are considered essential for life.
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