Why was it cold in the Apollo 13 CSM?

hello, world\n

usually spacecraft and astronauts on EVA must solve the problem of
getting rid of excess thermal energy.

During Apollo 13 there was a time when the temperature dropped so
low that the astronauts froze (close to zero centigrades?).

Why was it so? Was it due to the missing energy dissipated by the lost
fuel cells and all the electrical components not running and dissipating
energy? Was it the high reflectivity of the CSM that kept it from
warming up? Something else?


Regards,

Jens
--
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)

"Jens Schweikhardt" wrote in message ...

hello, world\n

usually spacecraft and astronauts on EVA must solve the problem of
getting rid of excess thermal energy.

During Apollo 13 there was a time when the temperature dropped so
low that the astronauts froze (close to zero centigrades?).

Why was it so? Was it due to the missing energy dissipated by the lost
fuel cells and all the electrical components not running and dissipating
energy? Was it the high reflectivity of the CSM that kept it from
warming up? Something else?


Correct. It was designed to account for the heat load generated by the
electronics.



Regards,

Jens

--
Greg D. Moore President Green Mountain Software
http://www.greenms.com
Help honor our WWII Veterans: http://www.honorflight.org/
Quidquid latine dictum sit, altum viditur.

"Jens Schweikhardt" wrote in message ...

hello, world\n

usually spacecraft and astronauts on EVA must solve the problem of
getting rid of excess thermal energy.

During Apollo 13 there was a time when the temperature dropped so
low that the astronauts froze (close to zero centigrades?).

Why was it so? Was it due to the missing energy dissipated by the lost
fuel cells and all the electrical components not running and dissipating
energy? Was it the high reflectivity of the CSM that kept it from
warming up? Something else?


Correct. The CSM was built to take into account the heat load of the
electronics.


Regards,

Jens

--
Greg D. Moore President Green Mountain Software
http://www.greenms.com
Help honor our WWII Veterans: http://www.honorflight.org/
Quidquid latine dictum sit, altum viditur.

Jens Schweikhardt wrote:

hello, world\n

usually spacecraft and astronauts on EVA must solve the
problem of
getting rid of excess thermal energy.

During Apollo 13 there was a time when the temperature
dropped so
low that the astronauts froze (close to zero centigrades?).

Why was it so? Was it due to the missing energy dissipated
by the lost
fuel cells and all the electrical components not running and
dissipating
energy? Was it the high reflectivity of the CSM that kept it
from
warming up? Something else?


Far away from Earth, like Apollo 13 was, is a much colder
environment than LEO, because the Earth is so much smaller.
And even in LEO, the EVA crew get very cold hands, to the
point of frostbite. It's all a complex thermal balance, so
some parts get hot and some parts get cold.

Mike Ross

On 11/11/2011 2:02 PM, M Ross wrote:



Far away from Earth, like Apollo 13 was, is a much colder
environment than LEO, because the Earth is so much smaller.
And even in LEO, the EVA crew get very cold hands, to the
point of frostbite. It's all a complex thermal balance, so
some parts get hot and some parts get cold.

Mike Ross


This was a joke post, right?

Strider came up with the proper answer.

On 11/11/2011 2:02 PM, M Ross wrote:



Far away from Earth, like Apollo 13 was, is a much colder
environment than LEO, because the Earth is so much smaller.
And even in LEO, the EVA crew get very cold hands, to the
point of frostbite. It's all a complex thermal balance, so
some parts get hot and some parts get cold.

Mike Ross


This was a joke post, right?

Why do you say that?

Strider came up with the proper answer.

And Mike added to that. He's correct. In LEO the thermal issue is far
different because you do have a large "warm" Earth filling 1/2 the sky. So
while his answer may not have directly answered the original poster's
question, it is accurate. And had the Apollo CSM been in LEO, the CM
probably would NOT have gotten nearly as cold.





--
Greg D. Moore President Green Mountain Software
http://www.greenms.com
Help honor our WWII Veterans: http://www.honorflight.org/
Quidquid latine dictum sit, altum viditur.