I'd like to add, though it's not particularly relevant, that Hollywood film studios do lose their master copies, or have them altered or destroyed by improper storage techniques. This is less of a problem now-a-days; but prior to VCR's, many studios simply failed to foresee a need to spend a lot of money to keep the originals.

Film in any format is not necessarily the easiest thing to store; it requires temperature and humidity control, aswell as regulated exposure to light. The more film you have, the more expensive it gets to store it in a long-term manner. I can't say it was the case for NASA, but you reach a point where percieved value of the film is less than the cost to preserve it. Particularly when you have the video in other, more easily stored formats.

__________________

I'm like one of those idiot savants...well, except for the savant part.
"In order to increase awareness of the homeless, security have been given binoculars."