The Lunar Orbiter program was very successful in mapping the surface of the Moon. Images were taken on a 70 mm film, developed in a semidry process, and then scanned by a photomultiplier for transmission to Earth. But how to develop a film in zero gravity? Semidry is not without any liquids, but liquids are difficult to handle in zero gravity.
The semidry process was used before in classified reconnaissance satellites, may be some details are still classified.
It appears that the Eastman Kodak "Bimat" system used on the Lunar Orbiters was completely dry - in the sense that there were no free liquids.
You can read about the process in detail at the Central Intelligence Agency's library website in this document. The pdf format used does not allow copying text, so here is an brief excerpt.
No free liquids are required at the time of processing negative films. Liquids cannot be squeezed or shaken from the BIMAT Transfer Film. Thus, the solution containment problem is completely eliminated from photographic processing. This is important in airborne processors and those operating in a space environment...
There is a good schematic of the system, here, on page 250.
You can see how the "Transfer Film", soaked in the "imbibant", is pressed against the film by a roller called the Processor Drum "for a suitable length of time." The developed film then passes by a dryer and on to the film scanner.
