1950s-70s USA and Russia philatelic covers that are related to the early satellites development, manned and unmanned spaceflights to the moon.
1964-11-28 USA Mariner 4
Mariner 4 launch cover signed by Jack N. James (Project Manager of the Mariner Program), Dr. Robert J. Parks (Planetary Program Director of Jet Propulsion Laboratory), Mr. Dan Schneiderman (Mariner Spacecraft System Manager), Dr. John A. Simpson (Principal Investigator), Dr. Joseph J. O'Gallagher (Other Investigator).
Mariner 4 was the first spacecraft to fly by Mars, and the first to return close-up images of the Red Planet.