Saturn V
The Saturn V (Saturn five) was a three-stage rocket developed by the United States primarily for sending astronauts to the Moon.[1] Used in the 1960s and 1970s, it is the most powerful rocket launched successfully and the only one that has taken humans beyond earth orbit. This power enabled it to launch the Skylab space station into space in 1973.[2] The project was extremely costly, $6.417 billion USD being spent between 1964 and 1973 on research, development, construction and flights, meaning each launch is thought to cost somewhere in the region of $185 million to $189 million.[3] This is equivalent to $41.4 billion USD when adjusted for 2016 dollars or $1.23 billion per launch.[3] A total of 13 missions were flown with no loss of crew or cargo.
History
The Saturn V rocket was designed and developed NASA's Marshall Space Flight Center in Huntsville, Alabama.[1] Saturn was the name given to a series of rockets. The first rockets developed were given the designations Saturn I and Saturn IB. These were utilised to launch manned spacecraft into orbit around the Earth as well as some satellites.[2] The first firing of a Saturn class rocket was of the Saturn I on October 27, 1961.[2]
Later rockets improved on these designs and finally in November 1967 the first Saturn V was built with the ability to take people to the Moon.[4] The mission was codenamed Apollo 4 and like most of the early launches was unmanned. The rocket was launched from Pad 39A at the Kennedy Space Center. Having undergone several months of testing, the engines of the rocket were ignited at 7 AM on November 9, 1967 and the rocket slowly lifted off. The launch went according to plan, placing the Apollo 4 capsule in a circular orbit above the Earth. The craft was then put into an elliptical orbit so that when it returned to Earth, it would be travelling at some 24,917 mph.[4] This enabled the heat shield to be tested as if the craft had returned form the Moon. After 8 hours and 37 minutes, the spacecraft splashed down in the Pacific Ocean and was recovered by the aircraft carrier, USS Bennigton.[4]
Then on December 21, 1968 the first manned launch was made, Apollo 8.[5] The craft was sent to the Moon, but did not land and instead orbited it. This demonstrated the Saturn V launch vehicle was sufficiently powerful to reach the Moon. The astronauts, Frank Borman, William A. Anders, James A. Lovell Jr, became the first people in history to pass behind the Moon and observe its dark side. The later missions of Apollo 9 and Apollo 10 involved testing of the lunar lander. This finally culminated in Apollo 11's famous landing on the Moon. The next Apollo mission from 12 to 17 (except Apollo 13 due to a technical failure of the Apollo spacecraft, specifically the service module) landed men on the Moon and also returned samples of the lunar bedrock.[1]
The final launch of a Saturn V launch vehicle occurred on May 14, 1973 and was used to launch the Skylab space station.[6] Strictly speaking, it was a modified Saturn V, with only two stages instead of three.[1] The astronauts who were due to launch the next day and join up with the space station also utilised a Saturn class rocket, though they used the smaller Saturn IB. During the launch it was believed that the "meteoroid protective shield" had been ripped of around 63 seconds into the flight.[6] The astronaut's launch was delayed until they had had time to practice using tools to repair the possibly damaged space station. They ultimately succeeded in fixing the station.
Design
The Saturn V was the largest rocket ever launched successfully. At 111 metres tall, the rocket was taller than the Statue of Liberty.[1] At lift off when it was fully fuelled it weighed 2.8 million kg and its engines produced 34.5 million Newtons (7.6 million pounds) of thrust.[1] As a heavy launch vehicle, it was capable of launching 50 tons of cargo to the Moon or 130 tons into orbit around Earth.[1] It was a multi-staged rocket which means that when the bottom stage has run out of fuel, it is ejected and then the next stages is ignited and takes over. This is a more efficient design than simply having one huge rocket.[7] The Saturn V had 3 stages.
The first stage, known as S-IC, was unsurprisingly the largest weighing some 2,000 tons.[2] It contained 5 F-1 engines powered by kerosene and liquid oxygen, each of which generated 1.5 million pounds of thrust.[8] Kerosene was used in the first stage as it is denser than liquid hydrogen, meaning the same performance could be achieved but using a fuel tank 12 times smaller than would be needed for liquid hydrogen.[8] The first stage would propel it to an altitude of around 42 miles and a speed of 5,400 mph before being discarded and falling into the ocean.[2]
At this point the second stage, S-II, would ignite. The second stage contained five smaller engines. Although smaller than the first, it still weighted in at around 450,000 kg and each engine created 200,000 pounds of thrust.[2][8] This stage used liquid hydrogen as a fuel instead of kerosene as it is more powerful and in the upper stages storage space is not such an issue.[8] With the rocket now lighter, the second stage would propel the craft to just under 14,000 mph before being discard at an altitude of 120 miles into the ocean.[2] At this point the spacecraft would nearly be in orbit around the Earth.
The third stage, S-IVB, would be fired for around 2.5 minutes. This would accelerate the craft to 17,000 mph and put it in an orbit around the Earth, known as a "parking orbit."[2] Then at the opportune moment, the astronauts on board would fire the third stage again for 5.5 minutes, before jettisoning it. This would accelerate the craft to 25,000 mph, the escape velocity of the Earth. This enabled the craft to escape Earth's gravitational pull and reach the Moon. The third stage would be ejected a few hours later after this burn was complete. Unlike the first and second stages, the third stage would either stay in orbit to continue on to impact with the Moon.[1]
At the very top of the rocket was the Apollo spacecraft. This contained the command module where the three astronauts would sit during take off and reentry.[9] It was shaped like a cone and around 3.9 m wide at its base and 3.2 m high.[10] Its base contained a heat shield to protect the crew from the extreme heat encountered on reentry. Just below it was the service module. This contained a rocket as well as liquid oxygen and liquid hydrogen tanks for it. It also house fuel cells to provide electrical power for the command module. It was cylindrical in shape, with a diameter of 3.9 m and a length of 7.5 m.[10] The command and service modules were joined together for most of the mission until reentry, and would be referred to jointly as the "command-service module."
Below the service module was the lunar lander. This is what would actually land on the Moon. The lander had two sections, the upper ascent stage and the lower ascent stage.[10] When landing on the Moon, the lower ascent stage possessed landing gear and a rocket that would be fired to slow the crafts descent. It also contained various experiments that the astronauts would deploy. When leaving the Moon, the lower section would be left behind. It would act as a platform for the upper stage to take off from. The two astronauts would travel in the upper stage. The lunar module was roughly 4 m wide and 7 m tall.[10] During take off, the lunar module was enclosed in a protective housing known as the "lunar module adaptor."
At the very top of the rocket, above the conical command module, was the launch escape system or escape tower which contained a solid fuel rocket.[11] If there was an emergency during the launch, the escape system would fired and pull the command module with the astronauts a safe distance away from the rocket, where they could descend using parachutes. If no problems were encountered during the launch, the escape tower would be jettisoned once the astronauts were in space.
External links
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 What Was the Saturn V? from nasa.gov
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Saturn launch vehicle from britannica.com
- ↑ 3.0 3.1 FALCON HEAVY VS. SATURN V from universetoday.com
- ↑ 4.0 4.1 4.2 50 years ago: The First Flight of the Saturn V from nasa.gov
- ↑ Apollo 8 from nasa.gov
- ↑ 6.0 6.1 40 Years Ago, Skylab Paved Way for International Space Station from nasa.gov
- ↑ Booster Staging from spaceflightsystems.grc.nasa.gov
- ↑ 8.0 8.1 8.2 8.3 Saturn the Giant by Wernher von Braun from history.msfc.nasa.gov
- ↑ What Was the Apollo Program? from nasa.gov
- ↑ 10.0 10.1 10.2 10.3 Saturn V rocket from space.com
- ↑ A Quick History of Launch Escape Systems from airandspace.si.edu
