Everyone who lived through the historic night of July 1969 remembers Armstrong and Aldrin setting up and greeting the American flag before engaging in dialogue with President Nixon, much to the dismay of the experts who were eager to see them continue collecting samples. The presence of this flag on the Moon had previously caused a great deal of excitement.
(This article below is a translation in English of the full French story from Serge Gracieux website.

Two years earlier - on February 25,1967 - the United Nations adopted a treaty setting out the major rules for the exploration and use of space and celestial bodies such as the Moon. Article 2 thus meant that no claim to national sovereignty would be possible by any nation. Signatories to the treaty, the United States, could therefore not "annex" the Moon.
When it became clear that the Apollo program was running smoothly and that mission 11 was going to be the one where the first men would set foot on the lunar soil, Thomas Paine - the administrator of NASA - appointed on 25 February 1969 a commission to define the symbolic activities of the first moon landing. This commission swept away the rumors already running at NASA that the United Nations flag would be flown on the moon. She recommended planting the flag of the United States during the only selene outing.

To avoid any confusion between exploration and conquest, this commission also recommended the famous commemorative plaque placed on the foot supporting the ladder of descent of the lunar module, which stated:"We came in peace in the name of all humanity".
Finally, other flags such as those of the 50 American states, the District of Columbia (the District of Washington, the federal capital), member states of the United Nations and some other countries took their place in the lunar module to be offered upon return from the mission. However, it would appear that a copy of the United Nations Charter was left on our natural satellite by the crew of Apollo 11.

Robert Gilruth, director of the Manned Spacecraft Center in Houston, appointed Chief Technical Officer Jack Kinzler to complete the mission in three months. The latter suggested the use of a standard size flag (5 x 3 feet, 152 x 91 cm) directly from the government supply catalogue and drew a first sketch that captured the project.

Mass and volume constraints required the design of an aluminum mast (1 inch in diameter, or 2.5 cm) in two sliding parts. The first, nearly one metre long, was intended to be planted in the ground with the geological hammer. A painted red strapping gave a borderline sink point. The second part, made up of the rest of the mast with the horizontal articulated bar, supported the flag where hems had been judiciously distributed. All the metal parts were reinforced by an anodized layer which gave the matt its golden colour.

As the Lunar Module (LM) was already heavily loaded and space was limited, it was decided to place the flagpole and mast along the descent ladder on the left side in a small, easily accessible container.
However, this area would be subject to significant thermal stress. In addition to the usual thermal deviations in space, the bottom of the ladder would be affected by hot gases (121°C) from the engines during descent. But for the last 13 seconds, these hot gases would reach almost 1,093°C! Also, a container, composed of a sandwich of stainless steel, insulation and aluminium, limited the interior temperature to 82°C... for a flag capable of withstanding 149°C.
The cost of this flag operation proved to be relatively modest: $5.50 for the flag, $75 for the mast and an estimate of a few hundred dollars for the container. The prototype took only a few days to complete. Packing procedures such as deployment on the Moon were also quickly frozen by a team of no more than 5 people.

The final packaging of the Apollo 11 flag took place in Jack Kinzler's office, assisted by the quality engineer. There was some excitement in this office as the final decision to place only the American flag and commemorative plaque on Mission 11 was made shortly before the launch. A Lear Jet plane was chartered outright to transport the two precious objects.
Jack Kinzler was on the trip, assisted by George Low, Apollo Program Director, and his secretary. The plaque and flag were installed on the LM on May 1,1969 at 4 a. m., shortly before the entire ship was hoisted and assembled on the Saturn 5 rocket. Only 2 months and 2 weeks before the launch. A really "limit" period for adding material to a mission of this kind.

4 days, 14 hours and 9 minutes after the take-off of the Saturn 5 of Apollo 11, Neil and Buzz unfurled the flag under the violent Sun of the Tranquility Base. The two men had a few worries to push the lower part of the mast into the ground, as the underlay was so strong (15 to 20 cm deep). This flag raising took them only 10 minutes out of the 2:30 AM exit in a suit.

There were some protests regretting the presence of this flag in place of the United Nations flag. In response, MP Richard L. Roudebush then proposed an amendment to ensure that the American flag would be the only one to be flown in future lunar explorations. On November 4,1969, the U. S. House and Senate endorsed this decision for future Apollo missions, stating that "the funds to carry out this mission came from the U. S. government and that this act should be seen as a gesture of national pride and not as a claim to sovereignty".

After Apollo 11, the flag and its accompanying material (matt, container...) remained unchanged, except for a modification following an unexpected change during Apollo 12. Indeed, Conrad and Bean were unable to fully deploy the American flag, which remained frozen along the pole, due to the impossibility of engaging the horizontal bar. An improvement of the mechanism prevented this misadventure for the continuation of the program. The following Apollo missions carried more and more scientific equipment and means such as the Lunar Jeep. The flag ceremony remained, bringing a moment of retreat and meditation to each mission. In all, 6 flags were flown on the surface of the Moon (Apollo 11,12,14,15,16 & 17).

The flag of Apollo 11 was probably swept away by the thrust of the lift stage engine, about 15 metres from the LM. On several occasions, Buzz Aldrin claimed to have seen him fall. The same misadventure most likely happened at Apollo 12. The flag of Apollo 13 ended his career in the upper layers of the atmosphere with the LM, which saved the lives of the crew by serving as a rescue habitat. For Apollo 14, the take-off film leaves no doubt: the flag falls to the ground.
The last three, planted a little farther away from the LM, were probably able to stand upright in front of the sun for more than 30 years now. However, the "stars and stripes" of Apollo 17 is distinguished by an anecdote.

To pay tribute to the Apollo Flight Control Centre, which had mothered astronauts and vessels since the beginning of the program, geologist-astronaut Harrison Schmitt had the idea of deploying to the Moon the flag that had been in the control room for years. From the Moon floor, during the deployment, he declared that another identical flag accompanied them in the LM and that with Gene Cernan they would bring it back to Earth to return it to the control center. Since then, if you pass through Houston, visit this room which has become a museum where you can probably see this flag, which is unique in the world.

The title of this article is about the first American flag on the Moon. Perhaps it is time to consider that the proud "stars and stripes" of Apollo 11 is not the first American cloth flag on the Moon, because it seems that an engineer played a good trick at NASA. Three years before the LM Eagle of Apollo 11 landed in the Sea of Tranquility, little was known yet about the Moon. After the Soviet Luna probes and the first American Rangers who had transmitted a few photos before striking the selene ground, NASA launched the Surveyor program with the objective of landing on the Moon. On February 3,1966, Luna 9, once again hauling the Americans to the post, landed 100 km from the centre of the Clavius crater and transmitted the first panorama of another world.