When NASA's Viking mission successfully landed a spacecraft on Mars, they recorded tons of data including high-resolution images of the planet's surface on microfilm.

Microfilm is a medium under the microforming umbrella. From Wikipedia:

Microforms are any forms, either films or paper, containing microreproductions[1] of documents for transmission, storage, reading, and printing. Microform images are commonly reduced to about one twenty-fifth of the original document size. For special purposes, greater optical reductions may be used.

Of course we would have loved it if the NASA team had chosen some cinema quality film stock, but this is still a very interesting story about preservation and its importance at the highest levels.

And the little rolls of film are so cute!