Space Cover #435: Moon or Mars Lander?This 15 year anniversary cachet for Sputnik 1 was released on April 4, 1972, which is printed on the reverse of the postal stationery on which it appears. Under the design of the cachet "Mapc-3" ("Mars 3) is clearly printed. The very same lander that is shown on the stamp which is tied to the cover with an October 4, 1972 cancel is very similar to the artwork shown on the stationery.
The Scott's Catalog does not picture this stamp but in cross referencing it to the H.R. Pfau Catalog, "SOVIET UNION 1 – ASTROPHILATELIE", it is pictured as the fourth stamp in a set of six stamps released in concert with a cancel from Kaluga on October 4, 1972. However, there is not an actual release date shown there for some reason. That is also the date and place of the cancellation on this cover. However, the Scott's catalog shows it as being released on September 14 1972.
The Lollini catalog shows only the first stamp in the six stamp set, and that is a Sputnik 1 stamp. It does not list the subject of the other five stamps which include the launching of Vostok 2, the Space Walk of Leonov, this stamp which is "Lunokhod on the Moon", the fifth stamp which is "Venera (Venus) 7 descending to Venus, and "Mars and descending to Mars" (by parachute).
I found it interesting that the same design which is shown on this cover shows the Lunokhod lander on the moon to be Mars 3 on Mars. That lander was actually a pennant... The stamp design was attributed to Alexei Leonov, who also has signed this cover.