Project Mercury was the first human spaceflight program of the United States, running from 1958 through 1963. An early highlight of the Space Race, its goal was to put a man into Earth orbit and return him safely, ideally before the Soviet Union. Taken over from the US Air Force by the newly created civilian space agency NASA, it conducted 20 uncrewed developmental flights, and six successful flights by astronauts. The program, which took its name from Roman mythology, cost $2.68 billion. The astronauts were collectively known as the "Mercury Seven", and each spacecraft was given a name ending with a "7" by its pilot.

John Herschel Glenn Jr. was an American Marine Corps aviator, astronaut, businessman, and politician. He was the third American in space, and the first American to orbit the Earth, circling it three times in 1962. Following his retirement from NASA, he served from 1974 to 1999 as a U.S. Senator from Ohio; in 1998, he flew into space again at the age of 77.