Yes, there were several sizes of protective heatshield ablator plugs on the Command Module. The items in your original post are from the Aft Heatshield and are a larger diameter than those found on the Crew Compartment Heatshield as depicted in the image below. There were 59 threaded Aft Heatshield plugs, each with an o-ring seal around a metal base with "fiberous glass thread seal" according to an early NAA training manual. This design ensured a tight fit in the over-sized hole which itself allowed for access to the heatshield attachment bolts. The windows, hatch, and even access panels for the RCS and electrical connections utilized the smaller diameter ablative plugs, which numbered significantly higher across the Crew Compartment. The image below, showing an Aft Heatshield plug as removed but not encased in lucite, is helpful to identify the various parts of the plug not often included as part of the presentation. Typically it was the larger Aft Heatshield plugs that were encased and presented, with the thread seal almost always removed. Those with lucite presentations can see that small amounts usually remain near the top, as it was hard to separate from the charred outer surface (thanks to Scott for the hi-res photo above). For some missions the smaller plugs were also presented, but seemingly in lesser numbers based on auction history. |