On Nov. 2, 2008, the Phoenix Mars Lander stopped phoning home. Sitting in the Martian Arctic, suffering a slow death due to sunlight deprivation (the sun was dropping low on the Red Planet's horizon, reducing the amount of energy its solar panels could collect), the mission was officially dead.
However, now that the Martian northern hemisphere is entering summer, some scientists are excited about the possibility of thawing Phoenix. If this is possible, perhaps the Phoenix could live up to its name and rise from the ashes (or, in this case, ice).
But is that a possibility? Not really. But there's hope! And where Mars missions are concerned, there's usually a surprise in store. (Although you won't find me placing a bet on these odds.)
"We start listening in January for signals from our lander," said Peter Smith, Phoenix principal investigator at the Lunar and Planetary Lab at the University of Arizona in Tucson. "Our engineering team is quite curious to see how resilient the electronic systems are to the extreme cold of northern winter."
But these ‘extremes' are very extreme.
Although the lander was frozen to a temperature of -67 F (-55 °C) during tests on Earth, it is thought that Phoenix has endured a Mars winter low of -195 F (-126 °C). That's nearly three times colder than the lander was tested to endure. As a comparison, the coldest temperature recorded on Earth is -128.6 F (-89.2 °C) on July 21, 1983 in Russia.
The electronics on board Phoenix have a built-in "Lazarus mode" - a system that restores functions to the robot after extended periods of sleep (or deep-freeze) - but I'm very dubious that even if communications to Phoenix could be restored, any useful science would be hard to come by.
But that doesn't stop the ever-positive Phoenix team from trying.
"Clearly, future use of Phoenix instruments depends on the health of the system," Smith said. "If it fully recovers then we would start with an imaging campaign and measure soil properties with TECP [the thermal and electrical-conductivity probe], then progress to digging beneath the surface to see if the ice table has changed depth."
So we'll just have to wait and see if we hear from our chilly robot on Mars in January, but if we do hear from Phoenix, I won't expect it to do any science. I think its digging days are over.