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...).


1 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 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:

enter image description here

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

  • 2
    $\begingroup$ Great find! Seems to be censored here, lol upload.wikimedia.org/wikipedia/commons/thumb/7/7e/… $\endgroup$ Jul 14, 2021 at 20:59
  • 1
    $\begingroup$ @OrganicMarble how interesting! on the pad that same label seems to have been repainted (it's on the left here - note darker background) - I wonder if it got smudged and was reapplied? $\endgroup$ Jul 14, 2021 at 21:20
  • 1
    $\begingroup$ There are also pictures at Michoud of the mostly-painted/assembled units without them as well, which is interesting (example, example) $\endgroup$ Jul 14, 2021 at 21:21
  • 1
    $\begingroup$ Maybe they didn't paint the last digit in until it was stacked. $\endgroup$ Jul 14, 2021 at 21:21
  • 1
    $\begingroup$ I've found a lot of pictures where I can see that the label is there, but not read it. $\endgroup$ Jul 14, 2021 at 21:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.