Are there any markings that uniquely identify each Saturn-Apollo combination?

Question

This question made me wonder: are there any markings on the Saturn I/IB/V launch vehicle, Apollo service module or command module that uniquely identify each vehicle (i.e. AS-5xx)?

It doesn't have to be a mission-specific marking; it may also be e.g. an externally visible identification of a stage, the instrument unit, or CSM that can be uniquely linked to a mission. For example, if a particular SI-C stage had a big #6 painted on it, it could be linked to AS-506, which was used in Apollo 11.

I thought that the IU had some white markings on its black exterior that were unique to each unit, but I cannot find a reference for that (so I may have made that up...).

Answer 1

The detailed flight log at apollosaturn.com reports that "exterior markings remained identical for all vehicles" from Apollo 9 onwards.

However, there were still some slight variations, even if the paint markings were the same. For example, they note that the Saturn II insulation type changed.

The instrument unit had some more visible differences. These pictures are all taken from approximately the same angle during launch:

• Apollo 8
• Apollo 9
• Apollo 10
• Apollo 11
• Apollo 12
• Apollo 13
• Apollo 14
• Apollo 16
• Apollo 17

Apollo 8 and 9 have solid black bands at the top, covering the instrument unit and the top of the third stage; Apollo 10, 11 and 12 have a white patch (I think an access door for the instrument unit); Apollo 13, 14, 16 & 17 have two of these patches (and presumably so did 15?).

For closer inspection, there was at least one visible serial number. It's only just visible in these pictures, but here it is on Apollo 13:

This is the serial of that particular Saturn IC stage (S-IC-8), and seems to have been applied from Apollo 8 onwards.