[GunnyB]

The lander is expected to function for about 90 days with energy generated by the solar panels.

Why is this the case? I would think that Solar Panels would provide power as long as they functioned...

[AntiKev]

In 90 days the CO2 in the Martian atmosphere will start to sublimate from gas to solid. Shortly thereafter it will be encased in 1m of solid CO2.

[Reaganesque]

See reply #8.

[Empireoftheatom48]

I believe at some point winter will set in and the area will be in constant shadow. It was funny in the briefing, a question was asked about the power source for the Viking landers, The two scientists kind of looked at each other and gave a techno answer. The some one said NUCPOWER. They looked a little embarrassed. Here again is another example of the Wacko fringe telling us we can't use Nuclear power for our rockets and probes.

[Mike Fieschko]

In addition to being encased in dry ice, Phoenix landed above the Martian Arctic Circle, and, just as on Earth, the Sun is below the Martian horizon during winter. This means that there is no electricity available to the craft from its solar cells, and the batteries cannot be recharged.