President Kennedy's decision to land men on the Moon before 1970 required the quickest, most efficient method possible. Three landing schemes, described below, were proposed.
Direct-ascent utilized a single launch vehicle and one craft to land on the Moon and later return to Earth. This mode required no docking maneuvers in space, but did require a larger rocket than the Saturn V that was already in development. Such a rocket would have been extremely difficult to complete by 1970.
Earth Orbit Rendezvous (EOR)
EOR required launching the lunar spacecraft in pieces aboard several rockets and assembling them in Earth orbit. Each piece would serve a particular function during the mission and would then be discarded.
Lunar Orbit Rendezvous (LOR)
LOR required several craft, sent up on a single launch vehicle. Over the course of a lunar journey, each craft performed a specific part of the mission. After reaching lunar orbit, the lander separated from the main craft and descended to the surface. After performing its function on the surface, part of the lander would lift off for rendezvous with the orbiting ship that returned to Earth, leaving the lander in lunar orbit.
Associate Administrator Robert Seamans and Administrator James Webb selected the Lunar Orbit Rendezvous option in June 1962 after consultation with agency managers. This decision affected the basic design of the major vehicles of the moon journey, particularly the Saturn V rocket and the lunar module.
When Apollo began, neither the United States nor the Soviet Union possessed a rocket powerful enough to send humans to the Moon and back. Both the Americans and the Soviets had to develop a super-booster, or Moon rocket. The United States succeeded with the mighty Saturn V.
Saturn V is the largest rocket booster ever built by the United States. This rocket, a 3-stage, liquid-fueled launch vehicle, was designed to propel a crew of three astronauts and Apollo spacecraft on their way to the Moon. These giant rockets were used only 11 times, on Apollo missions 8 through 17 and for the Skylab Orbital Workshop.
The F-1 engine was developed to provide propulsion for the Saturn V rocket used during the Apollo lunar landing missions. Developed during the early 1960s, the Saturn V rocket was the largest rocket in the world and the F-1 was the most powerful rocket engine.
The first of the 3 stages of the Saturn Rocket (S-IC) was powered by a cluster of five F-1 engines developing a total of 33.4 million newtons (3.4 million kilograms; 7.5 million pounds) of thrust at liftoff. They burned 2,021,000 liters (534,000 gallons) of liquid propellants in the 2½ minutes before first stage burnout. By then the big rocket had reached 9,660 kilometers per hour (6,000 miles per hour) and an altitude of 61 kilometers (38 miles).
The five clustered F-1 engines provided propulsion solely for the first stage of the rocket, while J-2 engines provided propulsion for both upper stages (five on the S-II second stage, one on the S-IVB third stage).
The Apollo Launch Vehicle Crawler-Transporter was a large moving platform that transported the Saturn V rocket from the VAB (Vehicle Assembly Building) to the launch pad for the Apollo missions. It was used at the Kennedy Space Center, Florida, during the Apollo program of the 1960s and '70s.
Launch Vehicle Transporter Specifications
The Saturn-1B, a variant of the first stage of the three-stage Saturn V, was used during the Apollo Program to launch Apollo 7, the program's first Earth orbital flight with humans. In the 1970s, after the Moon landings, this rocket also was used to launch the crews of Skylab missions 2, 3, and 4 to the Skylab Orbital Workshop and the U.S. crew of Apollo-Soyuz Test Project.
Launch Vehicle Specifications
Faced with time and budgetary constraints, George Mueller, Director of the Office of Manned Space Flight, proposed testing the first Saturn V rockets with all live stages and a complete spacecraft. Previous rockets were tested one major component and one stage at time before a full test of a complete vehicle. Mueller's proposal, called "all-up" testing, was met with resistance. With the successful launching of Apollo 4, the first "all up" test, in November 1967, Mueller's decision was vindicated.
This test procedure for the Saturn V allowed NASA to meet the 1969 lunar goal, despite the setback of a tragic Apollo 1 fire in January 1967. It also saved money and equipment that later were used for the Skylab program.
This black-and-white television camera was carried on the flight of Apollo 7, the first piloted Apollo flight, from October 11-22, 1968. It was used by the Apollo 7 astronauts Walter A. Schirra, Donn R. Eisele, and Walter Cunningham during the first live telecast from space. The astronauts gave several video press conferences from Earth orbit during their flight. The camera has three attachable lenses: a 10mm lens, a wide angle lens, and an extra wide angle lens.
In October 1968, James Webb retired and was succeeded by Thomas O. Paine. At the same time, the Saturn V moon rocket, after only two test flights without crews, was pronounced ready for a piloted flight.
Upon taking office, Paine had to decide whether to send Apollo 8, the first manned mission aboard the Saturn V, to the vicinity of the Moon or only into Earth orbit. Paine chose the Moon, giving NASA valuable knowledge of spacecraft performance in lunar orbit.
During the 1960s the United States possessed a remarkable record of success in its human space flight missions. In a highly risky enterprise, NASA and the country endured only one searing tragedy. On January 27, 1967 the astronaut crew selected for the first piloted Apollo mission, Apollo 1, were in their spacecraft on Launch Complex 34. They were participating in a practice countdown for an Earth-orbit mission scheduled to start several weeks later. At 6:31 p.m., EST, fire developed in the Apollo command module and the three astronauts died by asphyxiation:
Edward H. White II, command module pilot
Virgil I. Grissom, mission commander
Roger B. Chaffee, lunar module pilot
"If we die, we want people to accept it. We are in a risky business and we hope that if anything happens to us it will not delay the program. The conquest of space is worth the risk of life."
-Virgil I. Grissom, after the Gemini 3 mission, March 1965
After this tragic fire, NASA introduced new safety features to improve protection of the astronauts. We remember these astronauts and their contribution to the space program.