Apollo 8

Apollo 8 (December 21–27, 1968) was the first crewed spacecraft to leave Earth's gravitational sphere of influence, and the first human spaceflight to reach the Moon. The crew orbited the Moon ten times without landing and then returned to Earth. The three astronauts—Frank Borman, Jim Lovell, and William Anders—were the first humans to see and photograph the far side of the Moon and an Earthrise.

Apollo 8 launched on December 21, 1968, and was the second crewed spaceflight mission flown in the United States Apollo space program (the first, Apollo 7, stayed in Earth orbit). Apollo 8 was the third flight and the first crewed launch of the Saturn V rocket. It was the first human spaceflight from the Kennedy Space Center, adjacent to Cape Kennedy Air Force Station in Florida.

Originally planned as the second crewed Apollo Lunar Module and command module test, to be flown in an elliptical medium Earth orbit in early 1969, the mission profile was changed in August 1968 to a more ambitious command-module-only lunar orbital flight to be flown in December, as the lunar module was not yet ready to make its first flight. Astronaut Jim McDivitt's crew, who were training to fly the first Lunar Module flight in low Earth orbit, became the crew for the Apollo 9 mission, and Borman's crew were moved to the Apollo 8 mission. This left Borman's crew with two to three months' less training and preparation time than originally planned, and replaced the planned Lunar Module training with translunar navigation training.

Apollo 8 took 68 hours to travel to the Moon. The crew orbited the Moon ten times over the course of twenty hours, during which they made a Christmas Eve television broadcast where they read the first ten verses from the Book of Genesis. At the time, the broadcast was the most watched TV program ever. Apollo 8's successful mission paved the way for Apollo 10 and, with Apollo 11 in July 1969, the fulfillment of U.S. president John F. Kennedy's goal of landing a man on the Moon before the end of the decade. The Apollo 8 astronauts returned to Earth on December 27, 1968, when their spacecraft splashed down in the northern Pacific Ocean. The crew members were named Time magazine's "Men of the Year" for 1968 upon their return.

In the late 1950s and early 1960s, the United States was engaged in the Cold War, a geopolitical rivalry with the Soviet Union. On October 4, 1957, the Soviet Union launched Sputnik 1, the first artificial satellite. This unexpected success stoked fears and imaginations around the world. It not only demonstrated that the Soviet Union had the capability to deliver nuclear weapons over intercontinental distances, it challenged American claims of military, economic, and technological superiority. The launch precipitated the Sputnik crisis and triggered the Space Race.

President John F. Kennedy believed that not only was it in the national interest of the United States to be superior to other nations, but that the perception of American power was at least as important as the actuality. It was therefore intolerable to him for the Soviet Union to be more advanced in the field of space exploration. He was determined that the United States should compete, and sought a challenge that maximized its chances of winning.

The Soviet Union had heavier-lifting carrier rockets, which meant Kennedy needed to choose a goal that was beyond the capacity of the existing generation of rocketry, one where the US and Soviet Union would be starting from a position of equality—something spectacular, even if it could not be justified on military, economic, or scientific grounds. After consulting with his experts and advisors, he chose such a project: to land a man on the Moon and return him to the Earth. This project already had a name: Project Apollo.

An early and crucial decision was the adoption of lunar orbit rendezvous, under which a specialized spacecraft would land on the lunar surface. The Apollo spacecraft therefore had three primary components: a command module (CM) with a cabin for the three astronauts, and the only part that would return to Earth; a service module (SM) to provide the command module with propulsion, electrical power, oxygen, and water; and a two-stage lunar module (LM), which comprised a descent stage for landing on the Moon and an ascent stage to return the astronauts to lunar orbit. This configuration could be launched by the Saturn V rocket that was then under development.