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Old January 28th 04, 01:30 AM
Henry Spencer
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Default Mars Rover longevity again limited by dust build-up

In article ,
Russell Wallace wrote:
...And so the electronics will see increasing
temperature swings, and increasing thermal-contraction stresses between
different materials. Fairly soon, things will start to crack.


That makes sense, though I'm surprised it isn't possible to find
materials that don't crack when put through heating/cooling cycles. Or
is it the case that it could be done, but would cost more than it'd be
worth?


There is very limited room to maneuver on this, because you need materials
that can do their jobs in other respects. In practice, one tries to avoid
gross mismatches of thermal expansion anyway, because there is some
exposure to heat in soldering etc., but often there is little or no choice.

And yes, economics do enter the picture as well. The MER project couldn't
possibly have afforded to custom-make all its ICs, for example.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |