Heat-Sinking from Mars rover ???

[zimbali]

Just was curious, with a very thin atmosphere in Mars (or somewhere in the space with almost nothing like vaccum)how it is possible to take the heat from electronic parts of a device like Mars rover and damp it out? Imagine the worst case that there is no air to conduct the heat, and you know that radiation is very low in temperatures less than 200C.

 

[zeitghost]

It's not exactly hot on Mars.

It's a problem keeping things warm rather than cooling them down.

Especially batteries at night.

rgds
Zeit.

 

[zimbali]

Zeit,
That's true and a good point I didn't think of. The temp range is -113 to 7 oC, but because the atmosphere is very very thin ( the pressure is 6.9 to 9 mbar) so the barrier conductivity falls very low that may lead to heat accumulation (?).

Heat damping is proportional to temp difference but on the other hand it is a linear function of thermal conductivity which I believe is very low.

 

[Comcokid]

Apparently, in addition to electrical heaters, they use some plutonium dioxide pellets for the natural decay heat. No doubt the athmosphere being 1% of Earth's makes heat loss less. See the following link:

http://science.howstuffworks.com/mars-rover4.htm

Where I work we regularly test electronics down to -40C. Few batteries and capacitors will handle this temperature. I can't even imagine what additional problems might be encountered going to -113 C !

 

[IRstuff]

It's just not a big problem.

Assuming 0.25 m^2 effective blackbody radiating area, Mars Rover can easily radiate more than 50W without getting above 50°C during daytime.



TTFN