Saturn V

Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, with three stages, and powered with liquid fuel. It was flown from 1967 to 1973. It was used for nine crewed flights to the Moon, and to launch Skylab, the first American space station.

the Saturn V remains the only launch vehicle to carry humans beyond low Earth orbit (LEO). Saturn V holds records for the heaviest payload launched and largest payload capacity to low Earth orbit: , which included the third stage and unburned propellant needed to send the Apollo command and service module and Lunar Module to the Moon.

The largest production model of the Saturn family of rockets, the Saturn V was designed under the direction of Wernher von Braun at the Marshall Space Flight Center in Huntsville, Alabama; the lead contractors were Boeing, North American Aviation, Douglas Aircraft Company, and IBM. A total of 15 flight-capable vehicles were built, plus three for ground testing. Thirteen were launched from Kennedy Space Center with no loss of crew or payload. A total of 24 astronauts were launched to the Moon from Apollo 8 (December 1968) to Apollo 17 (December 1972).

History

Background

In September 1945, the U.S. government brought the German rocket technologist Wernher von Braun and over 1,500 German rocket engineers and technicians to the United States in Operation Paperclip, a program authorized by President Truman. Von Braun, who had helped create the V-2 rocket, was assigned to the Army's rocket design division. Between 1945 and 1958, his work was restricted to conveying the ideas and methods behind the V-2 to American engineers, though he wrote books and articles in popular magazines.

This approach changed in 1957, when the Soviets launched Sputnik 1 atop an R-7 ICBM, which could carry a thermonuclear warhead to the U.S. The Army and government began taking serious steps towards sending Americans into space. They turned to von Braun's team, who had created and experimented with the Jupiter series of rockets. The Juno I rocket launched the first American satellite in January 1958. Von Braun considered the Jupiter series to be a prototype and referred to it as "an infant Saturn".

Saturn development

Named for the next planet after Jupiter, the Saturn design evolved from the Jupiter series rockets.
Between 1960 and 1962, the Marshall Space Flight Center (MSFC) designed a series of Saturn rockets that could be deployed for various Earth orbit or lunar missions.

NASA planned to use the Saturn C-3 as part of the Earth orbit rendezvous (EOR) method, with at least two or three launches needed for a single lunar mission. However, the MSFC planned an even bigger rocket, the C-4, which would use four F-1 engines in its first stage, an enlarged C-3 second stage, and the S-IVB, a stage with a single J-2 engine, as its third stage. The C-4 would need only two launches to carry out an EOR lunar mission.

On January 10, 1962, NASA announced plans to build the C-5. The three-stage rocket would consist of the S-IC first stage, with five F-1 engines; the S-II second stage, with five J-2 engines; and the S-IVB third stage, with a single J-2 engine.

The C-5 would undergo component testing even before the first model was constructed. The S-IVB third stage would be used as the second stage for the C-1B, which would serve both to demonstrate proof of concept and feasibility for the C-5, but would also provide flight data critical to the development of the C-5. Rather than undergoing testing for each major component, the C-5 would be tested in an "all-up" fashion, meaning that the first test flight of the rocket would include complete versions of all three stages. By testing all components at once, far fewer test flights would be required before a crewed launch.
The C-5 was confirmed as NASA's choice for the Apollo program in early 1962, and was named the Saturn V. The C-1 became the Saturn I and C-1B became Saturn IB. Von Braun headed a team at the MSFC to build a vehicle capable of launching a crewed spacecraft to the Moon. During these revisions, the team rejected the single engine of the V-2's design and moved to a multiple-engine design.

The Saturn V's final design had several key features. F-1 engines were chosen for the 1st stage, while new liquid hydrogen propulsion system called J-2 for the 2nd and 3rd stage. NASA had finalized its plans to proceed with von Braun's Saturn designs, and the Apollo space program gained speed.

With the configuration finalized, NASA turned its attention to mission profiles. There was a controversy between using a lunar orbit rendezvous for the lunar module or an Earth orbit rendezvous. The Manned Space Flight Management Council preferred LOR while the President's Scientific Advisory Committee preferred EOR. After a round of studies, James Webb confirmed on November 7 that a lunar orbit rendezvous for the lunar module was chosen. The stages were designed by von Braun's Marshall Space Flight Center in Huntsville, and outside contractors were chosen for the construction: Boeing (S-IC), North American Aviation (S-II), Douglas Aircraft ( S-IVB), and IBM ( instrument unit).

Selection for Apollo lunar landing

Early in the planning process, NASA considered three methods for the Moon mission: Earth orbit rendezvous (EOR), direct ascent, and lunar orbit rendezvous (LOR). A direct ascent configuration would require an extremely large rocket to send a three-man spacecraft to land directly on the lunar surface. An EOR would launch the direct-landing spacecraft in two smaller parts which would combine in Earth orbit. A LOR mission would involve a single rocket launching two spacecraft: a mother ship, and a smaller, two-man landing module which would rendezvous back with the main spacecraft in lunar orbit. The lander would be discarded and the mother ship would return home.

At first, NASA dismissed LOR as a riskier option, as a space rendezvous had yet to be performed in Earth orbit, much less in lunar orbit. Several NASA officials, including Langley Research Center engineer John Houbolt and NASA Administrator George Low, argued that a lunar orbit rendezvous provided the simplest landing on the Moon with the most cost–efficient launch vehicle, and the best chance to accomplish the lunar landing within the decade. Other NASA officials became convinced, and LOR was then officially selected as the mission configuration for the Apollo program on November 7, 1962. Arthur Rudolph became the project director of the Saturn V rocket program in August 1963. He developed the requirements for the rocket system and the mission plan for the Apollo program. The first Saturn V launch lifted off from Kennedy Space Center and performed flawlessly on November 9, 1967, Rudolph's birthday. He was then assigned as the special assistant to the director of MSFC in May 1968 and subsequently retired from NASA on January 1, 1969. On July 16, 1969, the Saturn V launched Apollo 11, putting man on the Moon.

Launch history

Description

The size and payload capacity of the Saturn V dwarfed all other previous rockets successfully flown at that time. With the Apollo spacecraft on top, it stood tall, and, ignoring the fins, was in diameter. Fully fueled, the Saturn V weighed and had a low Earth orbit (LEO) payload capacity originally estimated at , but was designed to send at least to the Moon. Later upgrades increased that capacity; on the final three Apollo lunar missions, it sent up to to the Moon. (It was never used to launch its full LEO payload capability.)

At a height of , the Saturn V stood taller than the Statue of Liberty from the ground to the torch, and taller than the Elizabeth Tower, which houses Big Ben at the Palace of Westminster. In contrast, the Mercury-Redstone Launch Vehicle used on '' Freedom 7'', the first crewed American spaceflight, was approximately longer than the S-IVB stage and delivered less sea level thrust () than the Launch Escape System rocket ( sea level thrust) mounted atop the Apollo command module. The Apollo LES fired for a much shorter time than the Mercury-Redstone (3.2 seconds vs. 143.5 seconds).

The Saturn V was principally designed by the Marshall Space Flight Center in Huntsville, Alabama, although numerous major systems, including propulsion, were designed by subcontractors. It used the powerful F-1 and J-2 rocket engines for propulsion; they shattered the windows of nearby houses when they were tested at Stennis Space Center. Designers decided early on to attempt to use as much technology from the Saturn I program as possible. Consequently, the S-IVB-500 third stage of the Saturn V was based on the S-IVB-200 second stage of the Saturn IB. The instrument unit that controlled the Saturn V shared characteristics with the one carried by the Saturn IB.

The Saturn V was primarily constructed of aluminum. It was also made of titanium, polyurethane, cork and asbestos. Blueprints and other Saturn V plans are available on microfilm at the Marshall Space Flight Center.

It consisted of three stages—the S-IC first stage, S-II second stage, and S-IVB third stage—and the instrument unit. All three stages used liquid oxygen (LOX) as the oxidizer. The first stage used RP-1 for fuel, while the second and third stages used liquid hydrogen (LH2). LH2 has a higher specific energy per unit mass than RP-1, which makes it more suitable for higher-energy orbits, such as the trans-lunar injection required for Apollo missions. Conversely, RP-1 offers higher energy density per unit volume and higher thrust than LH2, which makes it more suitable for reducing aerodynamic drag and gravity losses in the early stages of launch. If the first stage had used LH2, the volume required would have been more than three times greater, which is aerodynamically infeasible. The upper stages also used small solid-propellant ullage motors that helped to separate the stages during the launch, and to ensure that the liquid propellants were in a proper position to be drawn into the pumps.

S-IC first stage

The S-IC was built by the Boeing Company at the Michoud Assembly Facility, New Orleans