To protect the Apollo Command Module from the extreme heat of reentry, NASA chose an ablative heat shield composed of a brazed steel honeycomb substructure, a fiberglass honeycomb shell filled with phenolic epoxy resin. The shell material was designed to vaporize (ablate) as a result of atmospheric friction a process that would prevent heat from penetrating the crew compartment. The earliest test flights of Apollo command modules were designed in large part to test the performance of the heat shield.

This heat shield section is from the aft (blunt end) shield from Apollo Command Module 011, which was flown on the unmanned AS 202 test mission, the second unmanned, suborbital test flight of a production Block I Apollo Command/Service Module. As 202 was launched with the Saturn IB launch vehicle on August 25, 1966. The command module and heat shield were recovered and the latter subsequently subject to careful examination and testing.

Following completion of the tests (which were destructive in many cases), the heat shield was offered to the Smithsonian. In 1972, prior to shipping, it was cut up into small displayable pieces at the Smithsonian's request.