In 1961, the United States was in a position of weakness in spaceflight by comparison to the Soviet Union. However, President John F. Kennedy had no intention of allowing the nation to remain mired in the existing situation. After months of careful study and quietly working with the best technical minds in the country, the president was about to reveal his decision. The last part of the president’s “Urgent National Needs” speech, delivered to a joint session of Congress on May 25, 1961, called or an all-out American effort to alter current circumstances.

He called for a firm promise for a new course of action over an extended period of time. “I believe that this nation should commit itself to achieving the goal, before the decade is out, of landing a man on the Moon and returning him safely to the Earth. … This decision demands a major national commitment of scientific and technical manpower, material and facilities, and the possibility of their diversion from other important activities where we are already thinly spread. It means a degree of dedication, organization and discipline, which have not always characterized our research and development efforts.”

In summing up this initiative, Kennedy requested “every scientist, engineer, serviceman, technician, contractor and civil servant to personally pledge that the nation will move forward, with the full speed of freedom, in this exciting adventure of space.” He knew the risks involved; nevertheless, Kennedy was willing to commit the nation’s resources to the National Aeronautics and Space Administration (NASA) and the civil space program. Thus, Project Apollo was born.

Even before taking office, Kennedy called upon Jerome B. Wiesner from the Massachusetts Institute of Technology to head an ad hoc committee. This group concluded that the issue of national prestige was too great to relinquish it to Soviet leadership in space, and that the United States would have to enter the field in a significant way. But it was a dicey enterprise. What if the Soviets were to beat us to the punch? They already had twice twisted our tail in space, starting with Sputnik and the dawn of the Space Age.

The president, in close consultations with Vice President Lyndon B. Johnson (LBJ), had his finger on the pulse of Congress. Johnson also chaired the National Aeronautics and Space Council. Kennedy sought from the council a recommended course of action and strategy to overtake the Soviets in space. In a memorandum, the president asked LBJ to consider a lunar landing program. “Do we have a chance of beating the Soviets by putting a laboratory in space, or by a trip around the Moon, or by a rocket to go to the moon and back with a man?” Kennedy inquired. “Is there any other space program that promises dramatic results in which we could win?”

In 1961, a lunar landing was believed far beyond the scientific and technological capabilities of either nation. Thus, the early Soviet lead in space could not predetermine this outcome, giving the United States a reasonable way to recover a measure of lost status, a NASA analysis reasoned.

Meanwhile, Hugh L. Dryden, NASA’s deputy administrator, responded to a request for information from the space council about a lunar program by writing that there was “a chance for the United States to be the first to land a man on the Moon and return him to Earth, if a determined national effort is made,” according to NASA historians. He added that the earliest this feat could be accomplished was 1967, but that it would cost about $33 billion, a figure $10 billion higher than the whole projected NASA budget for the next 10 years.

Almost simultaneously, Wernher von Braun, director of NASA’s George C. Marshall Space Flight Center, Huntsville, Alabama, and head of the “big booster” program so necessary for a lunar effort, responded in a memorandum to a similar request from the vice president. “We have a sporting chance of sending a three-man crew around the Moon ahead of the Soviets” and “an excellent chance of beating the Soviets to the first landing of a crew on the Moon, including return capability, of course.” With an all-out crash program the United States could achieve a landing by 1967 or 1968, von Braun wrote.

Johnson had already worked with Congress, lining up leadership approval in committing the nation to an accelerated space endeavor. To quash any remaining doubts, congressional leaders called on NASA Administrator James E. Webb to provide a straight answer. Webb’s enthusiastic endorsement of landing a man on the Moon and bringing him home safely generated considerable congressional endorsement for Project Apollo. Johnson also met with aerospace and industry officials to gain their support.

Kennedy had made up his mind. He clearly grasped the enormity of his decision and the sacrifices required to enable an American to successfully set foot on the lunar surface. The entire world would be watching at every turn, assessing the probability of success. Only a month before Kennedy’s speech, Soviet cosmonaut Yuri Gagarin flew a single orbit around Earth aboard his Vostok 1 spacecraft, becoming an international hero. American astronaut Alan Shepard, aboard Freedom 7 on May 5, 1961, became the first American in space during a 15-minute suborbital flight.

NASA historians pointed out that Gagarin’s spacecraft weighed 10,428 pounds while Shepard’s weighed 2,100 pounds. Gagarin was weightless for 89 minutes; Shepard for only five minutes. Clearly, the United States had not demonstrated spaceflight equality with the USSR. After Gagarin’s mission, Kennedy and his administration knew that they had to find a way to reestablish the United States’ reputation as a leader in the eyes of the world. Just two days before the Gagarin flight, Kennedy discussed once again the possibility of a lunar landing program with Webb.

Historians today compare the scope of Project Apollo to building the Panama Canal or to building the atomic bomb during the wartime Manhattan Project. Landing on the Moon’s surface would require billions of dollars, the best scientific and engineering minds in the country, mobilizing civilian and military efforts, and a great deal of risk. However, there would likely be an immense return on investment from Project Apollo’s scientific and technical advances, with thousands of applications across all of U.S. industry. This technology leapfrog effect could pay huge industrial dividends for decades to come. NASA scientists and engineers obtained their wish with Kennedy’s announcement – a national space effort integrating both scientific and commercial components.

A unique confluence of political necessity, personal commitment and activism, scientific and technological ability, economic prosperity and public mood made possible that 1961 decision to move forward with the lunar landing program,” NASA officials said. But gearing up would not be an easy task. In meeting the strict Project Apollo time constraints mandated by Kennedy, personnel had to be mobilized. Only 10,000 civil service employees worked for NASA in 1960, but that number swelled to 36,000 by 1966. An early NASA decision was critical to Apollo’s success.

NASA would have to rely on outside researchers and technicians to complete Apollo, and contractor employees increased by a factor of 10, from 36,500 in 1960 to 376,700 in 1965. Therefore, the majority of personnel working on Apollo came from private industry, research institutions, and universities. During the 1960s, some 80 to 90 percent of NASA’s overall budget went to contracts for purchasing goods and services.

Moreover, the space agency had to move quickly to expand its physical capacity to accomplish the Apollo mission. The agency consisted of a small Washington, D.C., headquarters and three research centers – the Jet Propulsion Laboratory, Goddard Space Flight Center, and the Marshall Space Flight Center. NASA added three new facilities to meet lunar landing program demands. The Manned Spacecraft Center (later renamed the Lyndon B. Johnson Space Center in 1973) near Houston, Texas, was one. This center was to design the Apollo spacecraft and launch platform for the lunar lander. It also became home to NASA’s astronauts and the site of mission control.

The space agency greatly expanded the launch operations center near Cape Canaveral on Florida’s eastern seacoast, renaming it the John F. Kennedy Space Center in 1963. This installation’s massive Launch Complex 34 became the site for all Apollo booster firings. A huge and expensive 36-story (550-foot-tall) structure at the Cape became known as the Saturn/ Apollo rocket assembly facility. NASA also created the Mississippi Test Facility on a Deep South bayou. It later became the John C. Stennis Space Center in 1988. The NASA expansion cost more than $2.2 billion. Most of the money was spent before 1966, agency historians said.

Meeting Kennedy’s goal also required NASA to meld disparate institutional cultures into an inclusive organization moving along a single unified path. “Each NASA installation, university, contractor, and research facility had different perspectives on how to go about the task of accomplishing Apollo,” NASA officials said. Expanding the program management concept, NASA brought in military managers to oversee Apollo. A central figure in 1962 was Air Force Maj. Gen. Samuel C. Phillips, the architect for the Minuteman intercontinental ballistic missile program.

Phillips answered directly to the Office of Manned Space Flight at NASA Headquarters, which, in turn, reported to the NASA administrator. Phillips created an all-powerful program office with centralized authority over design, engineering, procurement, testing, construction, manufacturing, spare parts, logistics, and operations. A fundamental tenet of the program’s management was that three critical factors – cost, schedule, and reliability – were interrelated and would be managed as a group. This management approach would become a critical component in Apollo’s success. In terms of complexity, rate of growth, and technological sophistication, Apollo was certainly unique in American history.

Managing complex organizations and structures for completion of widely varying tasks was an important consequence of the Apollo program. This management concept, under Phillips, orchestrated more than 500 contractors working on both large and small aspects of the Moon landing program, NASA officials stated. For example, the prime contracts awarded to industry for the principal components of just the Saturn V booster included Boeing for the first stage; North American Aviation for the second stage; Douglas Aircraft Corporation for the third stage; Rocketdyne Division of North American Aviation for the J-2 and F-1 engines; and IBM for Saturn electronics.

The prime contractors, with more than 250 subcontractors, provided millions of parts and components in the Saturn launch vehicle. Each part had to meet exacting specifications for performance and reliability. So enormous was the overall Apollo endeavor that NASA’s procurement actions rose from roughly 44,000 in 1960 to almost 300,000 by 1965.

As planning for Apollo began, more than 10,000 separate tasks had to be accomplished to put man on the Moon. Each task had particular objectives, manpower needs, scheduling, and a complex interrelationship with many other tasks. But first, vital questions had to be answered in building the network of tasks leading to a lunar landing. Which tasks had to be done first? Which could be completed concurrently? What were the critical sequences? The network of tasks had to be divided into manageable portions, the key ones being determination of the environment in cislunar space and on the lunar surface and design and development of the spacecraft and launch vehicles. Other key tasks involved conducting tests and flight missions to verify the components and procedures, as well as selection and training of flight crews and ground support to carry out the missions.

Apollo’s takeoff from the surface of Earth headed for the Moon was not without inherent physical difficulty. Earth travels at 1,000 miles an hour as it rotates, and going into orbit requires reaching an exit velocity of 18,000 miles an hour, then speeding up to 25,000 miles an hour at the proper time and traveling 240,000 miles to another body in space. The Moon itself travels at 2,000 miles an hour relative to Earth. Then, the spacecraft must orbit around that body to drop a specialized landing vehicle onto its surface. Only then can lunar work begin – making measurements and observations, collecting samples, leaving instruments to send back data. Returning to Earth requires repeating the outward-bound process to return home, NASA officials emphasized.

In the early planning stages for Apollo, three different approaches to the moon were considered: direct ascent, rendezvous in Earth orbit, and rendezvous in lunar orbit. Each had advantages and drawbacks, NASA officials said. The choice of mission mode was an important milestone in Apollo development. Lunar orbit rendezvous meant considerable payload savings, which, in turn, reduced propulsion requirements on the order of 50 percent. However, reducing brute force also meant more skill and finesse would be needed.

“A module designed especially for landing on and lifting from the lunar surface had to mate with a module orbiting the Moon. Rendezvous and docking, clearly, were of critical importance. The Gemini program was created to provide greater experience than Mercury would in manned operations in space, especially in perfecting procedures on rendezvous and docking,” said Robert C. Seamans, Jr., a former deputy NASA administrator.

The unmanned Ranger, Surveyor, and Orbiter flight series contributed necessary cartographic, geologic, and geophysical data about the moon. All of these missions were in preparation for the flights with the powerful Saturn V launch vehicle first flown unmanned in late 1967,” Seamans said.

In preparation for Apollo, NASA launched five Orbiter satellites between August 1966 and August 1967, achieving all of their objectives. After the third mission, NASA officials announced they had sufficient data on the moon to press on with an astronaut landing. Work on the Apollo spacecraft stretched from November 1961 to October 1968, when the last test flight took place. The tests encompassed ground, suborbital, and orbital modes.

However, it was the all-important Saturn V that was so necessary for the moon mission. A calculated risk followed in November 1967, with the entire Apollo/Saturn combination. Another test took place in April 1968, and even though there were some anomalies, NASA declared the test program completed. The next launch would have astronauts aboard. In 17 tests and 15 piloted launches, NASA officials asserted, the Saturn booster family scored a 100-percent launch reliability rate. NASA leaders declared the Apollo command module ready for human occupancy.

While these development activities took place, tragedy struck the Apollo program. On Jan. 27, 1967, astronauts Gus Grissom, Edward White, and Roger B. Chaffee were aboard the Apollo/Saturn capsule scheduled to be used in the first manned spaceflight. The men were running a mock launch sequence, and several hours into it, a fire flashed in the pure oxygen atmosphere, engulfing the capsule and asphyxiating the astronauts. The nation and NASA were stunned. NASA launched an investigation to determine what happened and why. The space agency learned that a short circuit in the electrical system ignited combustible materials, fed by the oxygen-rich atmosphere.

NASA discovered the fire could have been prevented and called for more than a thousand wiring changes and other modifications to the spacecraft, including a less oxygen-rich environment. Capsule changes quickly emerged, and within a little more than a year it was ready for flight. However, with the public and congressional backlash, it would be 20 months before another launch.

Resuming flight, Apollo 7 was an Earth-orbiting mission that lasted 10 days and 20 hours, from Oct. 11-22, with Schirra, Donn F. Eisele, and R. Walter Cunningham aboard for 163 orbits of Earth.

On Dec. 2, 1968, Apollo 8 took off atop a Saturn V. Three astronauts were on board – Frank Borman, James A. Lovell, Jr., and William A. Anders – headed for an orbit around the Moon. Originally, Apollo 8 had been planned to test the lunar module in Earth orbit, but the module was not yet ready for flight. Officials at the highest levels were also worried that the Soviet Union might yet get a manned spacecraft to the Moon, and they decided to send Apollo 8 to orbit the moon and return to Earth. After one-and-a-half Earth orbits, the third-stage burn put Apollo 8 on a lunar trajectory. In lunar orbit for 20 hours during 10 orbits, this first manned lunar mission lasted 6 days and 3 hours. This “around-the-Moon-and-back” mission was designed to demonstrate translunar injection, command support module navigation, communications, and midcourse corrections.

Another element of this mission was to return high-resolution photographs of proposed Apollo landing sites and locations of likely scientific interest. Outbound, Apollo 8’s crew focused a television camera on Earth. For the first time, humanity saw its home from afar – a tiny, lovely, fragile “blue marble” hanging in the blackness of space, as NASA officials described it.

Only two more missions remained before the lunar landing main event – Apollo 9 and 10. In acquiring critical rendezvous and docking experience, Apollo 9 flight-tested the whole system – the booster, the command and service module, and the lunar module – in Earth orbit. This flight with all the lunar hardware involved a crew headed by James A. McDivitt, the commander; David R. Scott, the command module pilot; and Russell L. Schweickart, the lunar module pilot.

The mission lasted 10 days and 1 hour, and it was the first manned lunar hardware flight in Earth orbit. Schweickart performed 37 minutes of extravehicular activity (EVA). Human reactions to space and weightlessness could be studied in the 152 orbits. Approximately 70 hours into the 10- day mission in Earth’s orbit, the astronauts separated, rendezvoused, and docked the lunar module with the command module. As a result of unfavorable weather in the planned landing area, Apollo 9 completed an additional orbit before returning to Earth.

The second Apollo mission to orbit the moon, Apollo 10, was also the first to travel to the moon with a full Apollo spacecraft, consisting of the command and service module, called Charlie Brown, and the lunar module, named Snoopy. The primary objective of the mission was to demonstrate crew, space vehicle, and mission support facilities during a human lunar mission and to evaluate lunar module performance. This mission was a full dry run for the Apollo 11 mission, and operations except an actual lunar landing were performed.

On May 22, 1969, Thomas Stafford and Eugene Cernan entered the lunar module and fired the service module reaction control thrusters to separate the lunar and command modules. The lunar module was put into an orbit to allow low-altitude passes over the Moon’s surface, the closest approach bringing it to within 8.9 kilometers (5.5 miles) of the Moon. All systems on the lunar module were tested during the separation, including communications, propulsion, attitude, control, and radar. Then the lunar module and command module made rendezvous and redocked. This took place eight hours after the separation, on May 23. Thirty-one lunar orbits were achieved.

In addition to extensive photography of the lunar surface from both the lunar module and the command module, television imagery was transmitted to Earth. John Young, the third member of the Apollo 10 crew, captained the Apollo 10 command module. He continued to orbit the Moon while the other two astronauts went down toward the lunar surface. This all-important mission set the stage for what was to come with Apollo 11.

On July 16, 1969, the big event took place when Apollo 11 lifted off. After confirming the hardware was working well, the spacecraft began a three-day trip to the Moon. At 4:18 a.m. EST on July 20, 1969, the lunar module of astronauts Neil A. Armstrong and Edwin E. Aldrin landed on the lunar surface, radioing the cryptic “the Eagle has landed.” Meanwhile, Michael Collins orbited overhead in the Apollo command module.

After checkout, Armstrong set foot on the surface, telling millions who saw and heard him on Earth that it was “one small step for a man – one giant leap for mankind.” Aldrin soon followed him out, and the two plodded around the Sea of Tranquility landing site in one-sixth lunar gravity. The astronauts planted an American flag but omitted claiming the land for the United States, as had routinely been done during European exploration of the Americas. They collected soil and rock samples and set up scientific experiments. Armstrong and Aldrin left behind on the surface of the Moon a plaque mounted on the lunar module descent stage with an inscription reading, “Here men from the planet Earth first set foot upon the Moon, July 1969 A.D. We came in peace for all mankind.” The next day, the two astronauts launched back to the command service module orbiting overhead and began the return trip to Earth, splashing down in the Pacific on July 24. Apollo 11, in particular, met with ecstatic reaction around the globe, as everyone shared the success of the mission. Ticker-tape parades, speaking engagements, public relations events, and a world tour by the astronauts helped to create goodwill both in the United States and abroad.

Five more landing missions followed at approximately six-month intervals through December 1972, each of them increasing the time spent on the moon. The last three Apollo missions used a lunar rover vehicle to travel in the vicinity of the various landing sites. The scientific experiments placed on the moon and the lunar soil samples returned through Project Apollo have been a boon for scientific investigations of the solar system ever since. While the technology return has been significant, the Apollo program did not answer conclusively the age-old question of lunar origin and evolution.

Apollo 13 did not land on the Moon due to a malfunction, but the survival and safe return of the astronauts was considered by many to be NASA’s “finest hour.” Three planned Apollo missions – 18, 19, and 20 – were canceled.

NASA officials pointed out that when Apollo 11 landed on the Moon, mission control in Houston flashed the words of Kennedy announcing the Apollo commitment on its big screen. Both phrases were followed with these words: “Task accomplished, July 1969.” No greater statement could probably have been made. Any assessment of Apollo that does not recognize the accomplishment of landing an American on the Moon and safely returning before the end of the 1960s is not complete, for that was the primary goal of Project Apollo.

Apollo was not only a triumph of man’s desire to explore his universe but also of management in meeting enormously difficult systems engineering, technological, organizational, and integration requirements. Humankind’s first steps onto an extraterrestrial body with Project Apollo became a high point in U.S. space efforts. Perhaps more importantly, Project Apollo enabled the people of Earth to view their planet in a new way. This was critical to fundamental change as it treated the world to the first pictures of Earth from afar.

This story originally appeared in Apollo 11: 50th Anniversary of the Moon Landing.