Developing film in space

[Chris Livsey]

Quite correctly it was pointed out my "Isochrome" thread needed a better title, here it is

http://api.viglink.com/api/click?fo....damninteresting.com/faxes-from-the-far-side/

 

[fotch]

Quite correctly it was pointed out my "Isochrome" thread needed a better title, here it is

http://api.viglink.com/api/click?fo....damninteresting.com/faxes-from-the-far-side/

Very interesting read. Thank you.

 

[Theo Sulphate]

Very interesting indeed - thanks!

 

[wombat2go]

Chris , Thanks.
I have some questions, that maybe some on here can answer:

How was the craft powered?
I presume a need to keep that film and its mechanics and the chemicals,
and the flying spot scanner and its ( high temperature) thermionics around usual earth temperatures.
How did they keep all that within operating temp ranges in those early days?

Another question I have ( unable to find on internet search)
In the exposure of film, is the process sensitive to the temperature of the silver halide crystals?
For example will silver halide crystals made by our processes on earth create latent images at very low temperatures
( eg zero ~100 Kelvin),
compared to the small range we regard as normal ( say 253 to 323 Kelvin)
To put it simply, Does ISO vary with temperature?
I would appreciate any references on this.
Thanks

 

[Chris Livsey]

Very good questions.
I can help on the temperature:

https://www.osapublishing.org/josa/abstract.cfm?uri=josa-32-4-214

That this effect kicks in below -75C is probably why there are so few references.

[h=2]Abstract[/h]Spectral sensitivities at three different temperatures (approximately +25°C, −75°C, and −185°C) were determined for seven commercial emulsions. For the six optically sensitized emulsions, it was found that the efficiency of optical sensitization decreased as temperature was lowered, except that for three of the emulsions this decrease commenced only somewhere below −75°C. Efficiencies found at approximately −185°C ranged from 1/4 to 1/550 of their values at +25°C. The decrease apparently pertains to the transfer of the action of light from the dye to the silver halide.
© 1942 Optical Society of America

This one talks about the opposite, increase in sensitivity, but only to body temperature and as expected shows the opposite effect but the variables are pretty poorly controlled, looks like they were just seeing roughly what the error would be in their niche application.
http://www.ncbi.nlm.nih.gov/pubmed/9287089