The Apollo program
, also known as Project Apollo
, was the third United States human spaceflight
program carried out by the National Aeronautics and Space Administration
(NASA), which accomplished landing the first humans on the Moon
from 1969 to 1972. First conceived during Dwight D. Eisenhower's administration
as a three-man spacecraft to follow the one-man Project Mercury
which put the first Americans in space, Apollo was later dedicated to President John F. Kennedy
's national goal of "landing a man on the Moon and returning him safely to the Earth" by the end of the 1960s.
Kennedy's goal was accomplished on the Apollo 11 mission when astronauts Neil Armstrong and Buzz Aldrin landed their Lunar Module (LM) on July 20, 1969, and walked on the lunar surface, while Michael Collins remained in lunar orbit in the Command/Service Module (CSM), and all three landed safely on Earth on July 24. Five subsequent Apollo missions also landed astronauts on the Moon, the last in December 1972. In these six spaceflights, twelve men walked on the Moon.
Apollo ran from 1961 to 1972, and was supported by the two-man Gemini program which ran concurrently with it from 1962 to 1966. Gemini missions developed some of the space travel techniques that were necessary for the success of the Apollo missions. Apollo used Saturn family rockets as launch vehicles. Apollo/Saturn vehicles were also used for an Apollo Applications Program, which consisted of Skylab, a space station that supported three manned missions in 1973–74; and the Apollo–Soyuz Test Project, a joint Earth orbit mission with the Soviet Union in 1975.
The Apollo program succeeded in achieving its goal of manned lunar landing, despite the major setback of a 1967 Apollo 1 cabin fire that killed the entire crew during a pre-launch test. After the first landing, sufficient flight hardware remained for nine follow-on landings, with a plan for extended lunar geological and astrophysical exploration. Budget cuts forced the cancellation of three of these. Five of the remaining six missions achieved successful landings, but the Apollo 13 landing was prevented by an oxygen tank explosion in transit to the Moon, which disabled the command spacecraft's propulsion and life support. The crew returned to Earth safely by using the Lunar Module as a "lifeboat" for these functions.
Gerard Kitchen O'Neill
(February 6, 1927 – April 27, 1992) was an American physicist
and space activist. A faculty member of Princeton University
, he invented a device called the particle storage ring
for high-energy physics experiments. Later, he invented a magnetic launcher called the mass driver
. In the 1970s, he developed a plan to build human settlements in outer space, including a space habitat
design known as the O'Neill cylinder
. He founded the Space Studies Institute
, an organization devoted to funding research into space manufacturing
O'Neill began researching high-energy particle physics at Princeton in 1954 after he received his doctorate from Cornell University.
Two years later, he published his theory for a particle storage ring. This invention allowed particle physics experiments at much higher energies than had previously been possible. In 1965 at Stanford University, he performed the first colliding beam physics experiment.
While teaching physics at Princeton, O'Neill became interested in the possibility that humans could live in outer space. He researched and proposed a futuristic idea for human settlement in space, the O'Neill cylinder, in "The Colonization of Space", his first paper on the subject. He held a conference on space manufacturing at Princeton in 1975. Many who became post-Apollo-era space activists attended. O'Neill built his first mass driver prototype with professor Henry Kolm in 1976. He considered mass drivers critical for extracting the mineral resources of the Moon and asteroids. His award-winning book The High Frontier: Human Colonies in Space inspired a generation of space exploration advocates. He died of leukemia in 1992.