Background
The Apollo program was proposed in the early 1960s during the Eisenhower administration as a successor to the Mercury program. The Mercury program used a spacecraft that could only go into Earth orbit and carry only one astronaut, whereas the Apollo spacecraft was envisioned to carry not only three astronauts, but perhaps the moon as well. NASA manager Abe Silverstein chose to name the program after the Greek mythological god of the sun at the time, mentioning afterward that it was a name he had reserved for his son. Although plans were already underway at NASA, Eisenhower did not seem enthusiastic about the space program, and funding for the Apollo program never materialized.
President John F. Kennedy delivers a speech on the space program at Rice University on Sept. 12, 1962.
In November 1960, John F. Kennedy, who campaigned on a promise to make the United States fully outpace the Soviet Union in space exploration and missile defense, was elected president. Despite his enthusiasm for the space program, he did not immediately decide to begin a moon landing program after being elected president, and even planned to cut some programs with high costs and low returns. Kennedy did not know much about the space business, and the large amount of money needed for space exploration also made him afraid to make a decision easily. When NASA Administrator James Webb requested a thirty percent increase in the annual fiscal budget, Kennedy supported accelerating the development of large-scale propulsion but not other larger programs.
On April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first human in space, deepening U.S. fears of falling behind in the space race. The following day, in a meeting with the White House Science Committee, many lawmakers wanted to begin an immediate space program to ensure that the USSR would not fall too far behind in the race. On April 20, Kennedy sent a memo to Vice President Lyndon Johnson asking for his opinion on the U.S. space program and the possibility of the United States catching up with the Soviet Union. In his response the following day, Johnson argued that “we are neither doing our best nor are we at a point where the United States is staying ahead of the curve.” Johnson also mentioned that future plans to go to the moon were not only feasible, but could definitely give the United States a lead in the space race.
President Kennedy addresses Congress on May 25, 1961, on man’s plans to go to the moon
On May 25, 1961, JFK announced his support for the Apollo program in a special session of the Senate and the House of Representatives.
A month before Kennedy delivered this speech, the United States had just sent its first astronaut into space and had not yet entered Earth orbit. This unfavorable situation made some NASA staff members not very optimistic about the moon landing program.
Choosing a Mission Mode
Scenario map for direct takeoff or Earth orbit rendezvous
After the moon landing became the primary goal, decision makers in the Apollo program began to face how they could get astronauts to the moon as safely, economically, and simply as possible. Four options were considered.
Direct takeoff: This plan proposed a giant Nova rocket carrying a spacecraft that would fly directly to the Moon; the rocket would land on the Moon, take off again after the mission was completed, and fly back to Earth.
Earth orbit rendezvous: This plan would require two small rockets half the size of the Saturn V to send different parts of the lunar spacecraft into Earth orbit, rendezvous and dock. The entire spacecraft landed on the lunar surface. This plan was not adopted because there was little experience with assembling multiple spacecraft in orbit at the time, and the feasibility of assembling a spacecraft in Earth orbit was unknown.
Lunar surface assembly: This plan required two spacecraft to be launched: an autonomous spacecraft carrying a propulsion system to go to the Moon first, and a manned spacecraft to be launched later. The propulsion system was moved to the manned spacecraft on the lunar surface and then returned to Earth.
Lunar Orbital Assembly: This option was proposed by John C. Hobolt’s team. This option is a larger spacecraft, called the command/service module, carrying a lunar spacecraft loaded with astronauts, called the lunar module. The Command/Service carries the fuel and necessities to get from Earth to the Moon and back, as well as the heat shields needed to enter Earth’s atmosphere. After entering lunar orbit, the Lunar Module separates from the Command/Service and lands on the lunar surface; the Command/Service remains in lunar orbit, and one of the three astronauts remains in the Command/Service. After the lunar landing is completed, the lunar module re-takes off, rendezvous with the command/service in lunar orbit, and returns to Earth.
Unlike several other options, the lunar orbit rendezvous requires only a very small spacecraft to land on the lunar surface, making the mass of the spacecraft taking off on the Moon on return much smaller. By leaving a portion of the lunar module on the Moon, the lunar takeoff mass is again reduced.
The lunar module proper is in two parts, including the landing part, which is used to land during the lunar landing, and the takeoff part, which will be combined with the command/service module to return to Earth after the mission is completed. Due to the reduced mass of the spacecraft, only one separate rocket launch was required for a mission. The concern at the time was the technical difficulty presented by the higher number of dockings and separations.
Spacecraft
The final selection of the lunar orbit assembly meant that the spacecraft would consist of three main components: the command module, the service module, and the lunar module.
Command/Service Module
Apollo Command/Service Module
The Command Module returned to Earth and descended to the surface of seawater.
The Command Module (CM) is conical in shape and is used to carry the astronauts from the surface all the way to lunar orbit, and is the only part that returns to Earth at the completion of the mission. Command Module equipment includes reaction control thrusters, docking ports, navigation systems, and the Apollo navigation computer. The Service Module (SM) stores a variety of equipment needed by the astronauts, such as service propulsion systems, fuel, oxygen tanks, maneuvering vents, and communication antennas. During the Apollo 15 mission, the thrusters for the spacecraft’s entry into lunar orbit were also located at the end of the Service Module. The command module and service module are known as the Command/Service Module (CSM). The Service Module also carried the Science Instrument Module. Before returning to the atmosphere, the Service Module is discarded. Only the outer layer of the Command Module has heat shields that can withstand the high temperatures upon entry into the atmosphere. After entering the atmosphere, the Command Module opened its parachute, gradually slowed down and landed on the surface to await rescue.
North American Aviation was successful in its bid to win the contract for the command/service module, which was headed by Harrison Storms. The relationship between North American Aviation and NASA was strained for a time, especially after the Apollo 1 fire that killed three astronauts. The fire was caused by a short circuit in the electrical wiring inside the command module, and the cause was complex, with the investigation team concluding that “there were problems with the design, manufacturing process and quality control of the command module.”
Lunar Module
The lunar module on the surface of the moon.
The lunar module is the part that will be used for the actual lunar landing. To keep weight as low as possible, the lunar module has no heat shields, very little power, and can only fly on the lunar surface. The LEM is capable of carrying two astronauts and includes a landing section and a takeoff section. The latter uses the former as a launch platform at the completion of the lunar mission and docks with the command/service module after entering lunar orbit in preparation for return to Earth. The landing segment also contained the Apollo science experiment package, as well as the lunar rover for the final three missions.
Grumman Aerospace designed and built the lunar module, headed by Tom Kelly. The lunar module also had many problems; the entire Apollo program came close to not succeeding because of delays in its testing. Due to the slow progress of the lunar module, the first manned flight of the lunar module had to be postponed, making Apollo 8 and 9 interchangeable. Apollo 9 used the lunar module for the first time in Earth orbit, and Apollo 10 took the lunar module to lunar orbit (but not to the Moon), where the entire spacecraft was tested in detail in all its parts.
Various missions
Map of the locations of the six lunar landings on Apollo 11, 12, 14, 15, 16, and 17
The Apollo program included 11 manned missions, from Apollo 7 through Apollo 17, all launched from Kennedy Space Center in Florida. Apollo 4 through Apollo 6 were unmanned test flights (officially no Apollo 2 or Apollo 3).
In September 1967, the Manned Space Center in Houston proposed a series of missions to complete the moon landing. Seven mission types were proposed, each testing a specific spacecraft and mission; the execution of each mission type required the successful completion of the previous type. These mission types are
A – Unmanned Command/Service Module Test
B – Unmanned Lunar Module Testing
C – Manned NEO Command/Service Module flight
D – Manned NEO Command/Service Module and Lunar Module flights
E – Manned Command/Service Module and Lunar Module in elliptical orbit around Earth, apogee 7400 km
F – Manned Lunar Orbit Command/Service Module and Lunar Module flight
G – manned lunar landing
Later, mission H was added, where the lunar surface stay was lengthened; the final mission, J, involved a three-day stay of the lunar module on the lunar surface. The canceled Apollo 18 to 20 were all J missions.
The most distant scenario even included an I mission, with a significant proportion of scientific research. When budget cuts became a reality, those scientific research projects were put into the J missions.
Saturn V, carrying Apollo 11, was launched on July 16, 1969 at 13:32 UTC (9:32 a.m. EDT)
Astronauts
The following astronauts flew missions in the Apollo program.
From the Mercury program 7 people
Walter Schiera – Apollo 7
Alan Shepard – Apollo 14
From the second group of astronauts
Neil Armstrong – Apollo 11
Frank Borman – Apollo 8
Pete Conrad – Apollo 12
Jim Lowell – Apollo 8, Apollo 13
James McDevitt – Apollo 9
Thomas Stafford – Apollo 10, Apollo-Union Test Program
John Young – Apollo 10, Apollo 16
From the third group of astronauts
Buzz Aldrin – Apollo 11
William Anders – Apollo 8
Alan Bean Apollo 12
Eugene Cernan – Apollo 10, Apollo 17
Michael Collins-Apollo 11
Walter Conyngham – Apollo 7
Don Eisley – Apollo 7
Richard Golden – Apollo 12
Russell Schweikart – Apollo 9
David Scott – Apollo 9, Apollo 15
From the fourth group of astronauts
Harrison Schmidt – Apollo 17
From the fifth group of astronauts
Charles Duke Apollo 16
Ronald Evans – Apollo 17
Fred Hess – Apollo 13
James Alvin Apollo 15
Ken Mattingly – Apollo 16
Edgar Mitchell-Apollo 14
Stuart Rossa-Apollo 14
Jack Swigert – Apollo 13
Alfred Walden Apollo 15
Returned specimens
Lunar iron calcite feldspar, No. 60025. recovered by Apollo 16 astronauts near Descartes Crater in the highlands of the lunar surface.
The Apollo missions brought back a total of 381.7 kilograms of lunar rock specimens, most of which are currently stored at the Lunar Material Recovery and Return Astronaut Quarantine Laboratory at the Lyndon B. Johnson Space Center in Houston.
After radiometric dating, the researchers found that the lunar surface rock specimens are all very old compared to Earth. The youngest lunar surface rocks are older than the oldest known rocks on Earth. Basalt specimens in the lunar sea are mostly around 3.2 billion years old, and specimens in the highlands even reach 4.6 billion years of age. This suggests that the Moon was formed in the early solar system.
The origin rocks found by David Scott and James Irwin during the Apollo 15 mission are among the most important of the lunar rock specimens and are thought to have formed at the birth of the Moon.
Many lunar rocks appear to be concentrated in impact craters formed by micrometeorites; a similar scenario is not possible on Earth due to the thicker atmosphere.
Controversy
With continued media coverage and insider disclosures by those involved, many people (reportedly about 20 million in the United States alone) believe that the Apollo program was a self-directed hoax of the century by the United States, and have raised various questions about its own feasibility. Those who question the authenticity of the moon landing claim to have found doubts based on photos of the moon released by NASA. Those who believe in the authenticity of the moon landings try to explain these doubts scientifically as reasonably as possible. At present, the vast majority of people still believe that the Apollo program is real, and believe that those who claim to “reveal the inside story” or try to deny the Apollo moon landings either have an economic or political agenda, or are pseudoscientists who promote pseudoscience.
Others
The total investment in the Apollo program was $19.408 billion (through 1973), or $135 billion in 2005. 1960-1973, NASA’s total budget was $56.661 billion. 1960-1973, the annual budget for the Apollo program and NASA’s annual budget both peaked in 1966, when the U.S. GDP was 815 billion dollars. The annual budget for the Apollo program that year was $2.967 billion, or 0.4 percent of U.S. GDP, and the annual budget for NASA that year was $4.512 billion, or 0.6 percent of U.S. GDP.
A total of 381.7 kilograms of lunar ore was brought back to Earth during the Apollo program. The vast majority of the ore is now kept at the Lunar Material Recovery and Return Astronaut Quarantine Laboratory in Houston. A small amount is distributed by the U.S. government to various laboratories around the country for analysis or as gifts to other governments.