Third-party evidence for Apollo Moon landings their orbits. According to the group, in December 1972 a member "picks up Apollo 17 on its way to the Moon". Paul Maley reports several sightings of the Apollo 12 Command Module. Chabot Observatory calendar records an application of optical tracking during the final phases of Apollo 13, on April 17, 1970: Corralitos Observatory photographed Apollo 14. Paul Wilson and Richard T. Knadle, Jr. received voice transmissions from the Command/Service Module in lunar orbit on the morning of August 1, 1971. In an article for "QST" magazine they provide a detailed description of their work, with photographs. Jewett Observatory at
Spacecraft call signs the three-man crews to name both craft for each of their missions, and these names were used as the call signs. A temporary exception to this was on the first Moon landing, Apollo 11: since the first Moon landing site was in the Sea of Tranquillity, the call sign "Tranquillity Base" was used while the LM was on the lunar surface. Before and after independent flight of the LM, the mission number was used as the call sign. The Apollo call signs were: For project Skylab, the practice returned to using the mission name as the spacecraft call sign, since