[TML] Astronaut prepares to risk life for spacewalk

[shadow at shadowgard.com]

On 4 Nov 2007 at 10:07, Traveller at dhimaging.com.au wrote:

> I think it's incredible that two astronauts - working side by side - can
> have a temperature difference of hundreds of degrees.  If one is in the
> shade of the shuttle and the isn't, the temperature extremes are incredible.
> What quality control measures are taken for tools and instruments that are
> exposed to such wildly different and quickly-changing temperatures?

Keep in mind that the tools are in a vacuum. So they aren't exposed 
to those temperatures at all.

So they only gain heat by absorbing sunlight falling on them or by 
conduction from objects they are in contact with.

They lose heat by radiating it away or conducting it to objects they 
come in contact with.

Radiation gains/loses are *slow* unles the object is very dark 
colored. And not that well polished.

Conduction is faster, but it also depends on how much is in contact 
and how good the contact is. And thermal conductivity comes into play 
as well.

Those huge temp differences you are always hearing about are 
*equilibrium* temperatures. And it takes a significant amount of time 
to reach equilibrium.


--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com