US 1969 10c First Man on the Moon Airmail Stamp

The centerpiece of most space collections, and the only stamp here whose printing tool has been to the Moon: the engraved master die for this 10-cent airmail flew with the Apollo 11 crew. The stamp itself went on sale on September 9, 1969, showing an astronaut stepping down from the lander with Earth hanging in the black sky. More than 152 million were printed, so this is about story rather than rarity. Paul Calle's design is crisp and still reads clearly at stamp size, which is why it anchors so many albums.