SOLVED:  The last known unidentified marking on the Saturn V S-IC.

For a hair over twenty years, I have been chasing the markings on the Saturn V.  Most have been fairly simple to figure out.  The second and third stages have well known markings and only the discovery of better period photographs would enhance that knowledge.  But the first stage or S-IC, built by Boeing, is a riddle which has resisted explanation.

Apollo 11 S-IC-6 in the transfer isle.  NASA

Boeing stenciled their part of the moon rocket extensively, using a font from their WWII bombers.  Beyond what is easy to see; i.e. the American Flag, "USA", fin letters, position markings, etc.  Boeing seemingly wanted to make sure everyone knew there was a vent or a hoist point for the fins.  The majority of these markings survived enough to be saved and cataloged by professional historians who oversaw the restoration of the remaining stages.  In some cases, the stages were cleaned and sandblasted with little regard for the original markings.  The preservation of the remaining Apollo hardware began in earnest in the mid-1990s and continues to this day.  The last production S-IC, number 15, has been moved from  the Mississippi Assembly Facility to it's new home at the Infinity Space Center where it awaits restoration. 

S-IC Boeing stencil fonts by John Pursely

I have photographed the Saturn stages in Florida Alabama and Houston, the latter being made up of all flight qualified stages.  They all shared the first stage markings before they were restored.  Now, they are clean and nice looking but each is missing markings.  Why does this matter?  It might not, except for rivet counters like me.  The most obvious marking which as been unexplained on the Saturn V is the strip or stripe just below the four position markings.  They are visible is most period photos of the stage but not in sufficient resolution to understand them.  I have studied every photo from the flight campaign as well as assembly images to no avail.  Last year, I started hunting for amateur photos from the early 1970s as a way to find a good image.  So far, nothing has turned up.

Position II of Apollo 8 S-IC with strip visible below.  NASA

Last year while photographing S-IC-15 at Infinity Science Center, I had thought I had finally found a first stage with this marking still intact.  I photographed both positions II and IV, those being the only ones visible.  The marking underneath the "IIII" marking was still there but covered with peeling paint.  The other side was much the same with nothing visible but dirt, mold and old paint.  I did my photography and returned home, hoping to glean something from the high resolution photos.  As I feared, nothing of note was visible in the images.  I resigned myself to searching for images on Ebay or perhaps in the National Archives in Atlanta, a resource I still need to visit.

Strip visible in Spring of 2017 covered in dirt and paint.

Last month (April of 2018) I joined a group of like minded Space Hipsters from the Facebook group of the same name for the yearly field trip.  I set about rephotographing things I missed on S-IC-15 as well as areas I couldn't reach on the previous visit.  I photographed the same areas on II and IIII, hoping something would reveal itself.  I examined the position IIII images upon my return and ignored the position II images since I thought the strip was missing.  I posted some images in the Saturn Rocket History group on Facebook, hoping to jog someone's memory about the marking.  Here is where it gets interesting, if you haven't already fallen asleep.  Richard Lobinske replied to my post with some images of his own, with better detail.  Naturally, since I was only looking at the marking below Pos IIII, I didn't see anything I could identify.  Fast forward to today and I am passing the time waiting for an appointment, looking at images hoping to find something.  Today I did.  I looked for the first time at Richard's image of the position II area and zoomed in on it.  There was something there!  I looked at my own images of the area from last month and it was in my photos too, just not as clear.  Below is a zoomed in crop of the strip under the Position II marking.  Apparently, over the last year, the stage was cleaned or maybe the weather and rain moved the old paint off of it.  It almost looks as though someone wiped it off.

We had always suspected that it was an alignment marking of some sort and now we know.  Notice that it is reversed.  This could be due to the alignment tool using an odd number of mirrors.  The reversed mark would look correct through the instrument if this is the case.

Success!!  Richard Lobinske photo.

Finally, I have found that Holy Grail that has eluded me and others in the Space Modeling community.  Thanks to Richard for sending me those images.  Now on to the next impossible discovery!!

--John Duncan