Another shot of the complex pipework around the third stage engines on Johnson Space Center’s Saturn V rocket.
Great image. Actually, that’s the third stage, also called the S-IVB. The canister and nozzle in the foreground is an oxygen/hydrogen burner whose function was to burn a little of the stage’s propellants (oxygen and hydrogen) in order to warm some extremely cold helium gas and expand it so that it could pressurise one of the giant propellant tanks. It did this in Earth orbit during the minutes before the S-IVB was ignited to send Apollo astronauts to the Moon.
Thanks for the correction and additional information, David! I had found and corrected this same error on a couple of other pictures earlier but I missed this one. I’ve updated the title and text.