The Saturn Rocket
The Saturn rocket evolved from the idea of clustering a number of Jupiter engines around Redstone and Jupiter propellant tanks to build a large launch vehicle. These engines, whose thrust would total 1.5 million pounds (6.7 million newtons), would be mounted on a structure consisting of eight 70-inch (178-centimeter)-diameter tanks clustered around a single 105-inch (267-centimeter) Jupiter tank.
The Department of Defense's Advanced Research Project Agency (ARPA) gave its approval to develop such a structure in August 1958. Development of the three-stage Saturn 1 began in December 1959.
In early 1960, the second stage was changed so that six less powerful engines replaced the four 20,000-pound second-stage engines, and the third stage was eliminated. Assembly of the first flight vehicle began in May 1960. The first 162-foot (49-meter)-long vehicle, weighing nearly 1 million pounds (453,592 kilomgrams) was launched on October 27, 1961, from Cape Canaveral.
At the same time, NASA was working on developing a larger vehicle, named the Saturn 1B, to serve as a launch vehicle for the test Apollo spacecraft. The first Saturn 1B suborbital flight took place on February 26, 1966, with an unmanned Apollo spacecraft as payload. Flight testing was halted in January 1967 after the fire that killed three astronauts. The carrier returned to service in January 1968, and by October, both the redesigned Apollo spacecraft and the Saturn 1B were judged safe for piloted flights. On October 11, the Saturn 1B successfully launched the crewed Apollo 7, the only piloted mission that used a Saturn 1 vehicle.
Saturns 1 and 1B were mere preludes to the Saturn V needed to propel a human crew to the Moon. Designed under the guidance of Wernher von Braun, the three-stage Saturn V would be the largest operational launch vehicle ever built. Standing more than 363 feet (111 meters) high with its Apollo spacecraft payload, the first stage produced nearly 7.7 million pounds (34 million newtons) of thrust at lift-off. The first Saturn V was launched in November 1967.
The Saturn V launch vehicle consisted of three stages:
The first stage included the five F-1 engines that lifted the heavy rocket fast enough to escape Earth's gravity. The second stage contained five J-2 engines producing 1.15 million pounds (5 million newtons) of thrust that took the vehicle and payload to 115 miles (185 kilometers) altitude. The third stage contained one J-2 engine producing 230,000 pounds (1 million newtons) of thrust. This engine boosted the spacecraft to orbital velocity and remained attached to the spacecraft in Earth orbit. The engine was reignited to propel the spacecraft into its lunar trajectory before finally being discarded.