Why did Mariner 4 look a little like my dad's old slide projector?

2018-04-08 04:35:09

The COSMOS Magazine article First mission to Mars: Mariner 4’s special place in history July 14, 1965, forever changed the way we see Mars. Tim Wallace looks back at one of NASA’s greatest triumphs recounts some of the excitement that NASA scientists and engineers must have felt during:

...humanity’s first up-close encounter with the Red Planet on July 14, 1965, when the pioneering Mariner 4 spacecraft took the first detailed photographs of the Martian surface, paving the way for future missions to successfully land a probe on the ground.

Remember, this is several years before the first Moon landing!

The article shows several views of Mariner-4, and this one reminds me of an old slide projector both because of what looks to be the central lens (is that Mariner's camera?) and what looks like louvers or air vents on either side.

Question: What are the structures on either side in this image, that look like louvers or air vents? What is their function?

above x2