US Post Office Department 4¢ Project Mercury Commemorative with Designated Apollo 1 Astronauts

U.S. POST OFFICE DEPARTMENT on 20 February 1962 issued a 4¢ Project Mercury commemorative stamp (shown on this First Day Cover) showing three of the  NASA astronauts for the Mercury and Gemini projects and later planned Apollo mission. The three astronauts -- Command Pilot Gus Grissom, Senior Pilot Ed White, and Pilot Roger B. Chaffee -- were killed in a cabin fire during a launch rehearsal test at Cape Kennedy Air Force Station Launch Complex 34 on 27 January 1967, hence the picture of them on this First Day Cover cachet.

Apollo 1, initially designated AS-204, was planned to be the first crewed mission of the Apollo programme, the American undertaking to land the first man on the Moon. It was designated to launch on 21 February 1967, as the first low Earth orbital test of the Apollo command and service module. The mission never flew following their deaths and the destroyed command module (CM). The name Apollo 1, chosen by the crew, was made official by NASA in their honour after the fire.

Had Gus Grissom survived, NASA had intended for him to be possibly the first man to step onto the surface of the moon, not Neil Armstrong. Deke Slayton wrote that he had hoped for one of the original Mercury astronauts to go to the Moon, noting: "It wasn't just a cut-and-dried decision as to who should make the first steps on the Moon. If I had to select on that basis, my first choice would have been Gus, which both Chris Kraft and Bob Gilruth seconded." Ultimately, Alan Shepard, one of the original seven NASA astronauts, would receive the honour of commanding the Apollo 14 lunar landing.

Source: Wikipedia