This First Day Cover bears the 10¢ Mariner 10 Venus/Mercury commemorative stamp, postmarked Pasadena, California on April 4, 1975, the official first day of issue. The cover carries a handsome Artmaster cachet illustrating the spacecraft against a starry backdrop with a large planet.
Mariner 10 was NASA’s pioneering interplanetary probe—the first spacecraft to visit Mercury and the first to use a gravity-assist flyby of Venus to reach its destination. Launched in late 1973, it returned the initial close-up images of Mercury’s cratered surface and provided valuable data on both planets during its three successful encounters.
The Artmaster cachet features a detailed drawing of the Mariner spacecraft with its twin solar panels and science instruments, captioned “UNMANNED MARINER First Day of Issue.” The Pasadena postmark ties the cover directly to the Jet Propulsion Laboratory, which managed the mission.
Addressed to Lorinda Alexander in Dillsburg, Pennsylvania, the cover remains in clean, collectible condition with sharp postmark and fresh colors.
An excellent addition for collectors of space exploration, NASA, or 1970s U.S. commemoratives.
