Holiday Inn sign wishing John Glenn good luck / astronaut John Glenn eating breakfast before mission / John Glenn suiting up / women spectators waiting for launch, looking through binoculars / sign saying 'Good Luck Glenn from the All...

Project Mercury astronaut John Glenn enters the Mercury-Atlas 6 (MA-6) Friendship 7 spacecraft wearing the full pressure suit and helmet / McDonnell Aircraft Corporation technicians assist. Project Mercury Atlas 6 Mission pre-flight...

Mercury Redstone 3 launches Alan Shepard into space as the first American into space on May 05, 1961 in Cape Canaveral, Florida (Footage by Getty Images)

Mercury 7 astronauts relaxing, surfing and waterskiing on January 01, 1961 (Footage by Getty Images)

Project Mercury Freedom 7 capsule being moved on January 01, 1961 in Cape Canaveral, Florida (Footage by Getty Images)

Astronaut Alan Shepard suiting up for Project Mercury III mission on July 28, 1961 in Cape Canaveral, Florida (Footage by Getty Images)

Project Mercury Redstone 4 astronauts pre-flight preparations / Virgil 'Gus' Grissom is suited up in space suit on July 21, 1961 in Cape Canaveral, Florida (Footage by Getty Images)

Project Mercury 7 astronauts strapped into gyroscopes during training on January 01, 1961 (Footage by Getty Images)

Seven astronauts pose beside a model of the Mercury 7.