[time-nuts] Space mission comes to an end becuase of a "computer time tagging" problem

[Chris Albertson]

On Sat, Sep 21, 2013 at 6:40 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
>

> What stops working when things get cold?
>
> On Mars, the solar cells are pointed in the right direction.  Why doesn't it
> recover when the sun comes back in the Spring?

They run out of power for running the battery heaters, then the
battery freezes and fails.  The batteries get to such a low
temperature that they are unable to be charged.  The rover was never
designed so that it could move and operate under solar power.  It is
really battery powered and uses the panel for charging.

This is the biggest reason the newest rover, "Curiosity" is powered by
an RTG, not solar cells.  The RTG is powered by radioactive decay.
The thing makes a lot of heat and should last 15 to 20 years. Likely
longer than all the moving parts like motors and so on.
-- 

Chris Albertson
Redondo Beach, California