Artifact 1:The History of Space Satellites
Starting from the beginning of the Cold War up until now, space satellites have been used to perform many different tasks. There are two different types of satellites; natural satellites and artificial satellites. Natural satellites are celestial bodies that orbit planets or moons. Artificial satellites are manmade objects that are created to orbit the Earth or other celestial bodies. Artificial satellites are one of the most useful satellites in the world today. People have used them to forecast weather, make long distance calls over seas, help the navigation of ships and aircrafts, relay information to military families, track the growth of crops and other natural resources, and gathering useful and interesting information about the planets.
There are many different types of satellite orbits like circular and egg-shaped orbits. These orbits also vary in their altitude as some are just above the atmosphere and others are thousands of miles above Earth. The higher the altitude of the satellite, the longer the period that it takes for it to complete its orbit. The lower the altitude of the satellite, the shorter time it takes. This is all because when there is low altitude, there is very little air to cause enough drag to slow it down. The only reason why a satellite stays in orbit is because there is a balance between the Earth’s gravitational pull and the satellites velocity.
The world’s first artificial satellite was launched on October 4, 1957, in the Soviet Union. This satellite was called Sputnik I. It was about the size of a basketball and it weighed around 183 pounds. In its elliptical path, it took about 98 minutes to orbit the Earth. This satellite found the density of various atmospheric levels as it measured its orbital change. The Sputnik provided this data on a radio-signal that sent signals through the ionosphere. As the Sputnik’s body and inside was filled with nitrogen, it was able to detect meteors. The Sputnik was designed like a sealed sphere container and it was covered by two semispheres that were two millimeters thick. These two semishperes were connected by 36 bolts. O-rings made sure that there would be a sealed blend between the semispheres. The top semishpere had two antennas with two beams each. A spring device moved the antennas 35 degrees toward the main axis of the container, right after the spacecraft separated from the rocket. On the outside of the satellite, there was a thick covering of thermal protective metal that was about one millimeter thick.
The Sputnik was the start of the space age and thenceforth there were many technological, military, political, and scientific developments. The Sputnik amazed and frightened many people. They had never seen any satellite like this before and it had surpassed any of the previous attempts and models of the past. The US feared that since the Soviet had made this huge technological advance that it meant that they had the ability to launch missiles that could carry nuclear weapons into the United States.
About one month later, the Soviet Union launched its second satellite called the Sputnik II. This satellite orbited the Earth and it carried the first living organism to ever go into space! The animal was a dog named Laika. The satellite was four meters high and it was cone shaped. It contained several things like a radio transmitter, a programming unit, a regeneration and temperature control system for a separate compartment, and scientific tools. On the satellite, there was also a sealed area for Laika that contained food, water, and substantial space for her to lie down. The satellite was able to measure solar radiation and cosmic rays. As the Sputnik II was in orbit, part of its core did not break free as planned and this damaged the temperature control system. As a result of this, Laika died after a few hours from the extreme heat. The Sputnik II remained in orbit for 162 days and it returned to the Earth’s atmosphere on April 14, 1958.
It all started in 1952, when the International Council of Scientific Unions wanted to make, from July 1, 1957,until December 31, 1958 the IGY, (International Geophysical Year). They proposed this because they knew that there would be high cycles of solar activity at that time. The US National committee oversaw the participation in IGY, and they were granted this position by NASA. Throughout this time span, they would examine and observe aurora and airglow, solar activity, oceanography, seismology, meteorology, longitude and latitude, the ionosphere, geomagnetism, cosmic rays, gravity, and the upper atmosphere. The US also wanted the artificial satellites to be launched so that they could be able to map the Earth’s surface.
Not long after the Sputnik II, on January 31, 1958, the US finally launched its first satellite called the Explorer I. The Explorer I was created by the Jet Propulsion Laboratory. It took about 114 minutes to take one orbit around the Earth and it made around twelve orbits per day. The satellite was about 80 inches long, 6 inches in width, and weighed around 30 pounds. It was designed to measure the radiation as it was in Earth’s orbit. After around 58,000 orbits, the Explorer I burned up on March 31, 1970. Many more attempts were made as they created around four more Explorers, but each of these had technical problems and failed to last long in orbit or launching.
Many more advances in technology are being made today. One of them is the idea of a “satellite that bleeds.” This is the idea of a satellite that is able to heal and repair itself while in orbit. Satellites are in many different types of weather as they orbit and they are hit by pieces of rock, exposed to extreme temperatures, and are capable of being damaged in many ways. Satellite builders thought of this idea as they thought about humans’ way of repairing cuts or injuries. In the same way that humans use capillary action to draw blood out to block a cut, they think of a satellite doing the same thing. The satellite builders thought that instead of blood they could use resin, a gooey adhesive, and instead of veins they would use tiny glass tubes to fill in the cracks of the satellite exterior. By healing themselves in orbit, satellites would be able to stay in orbit much longer and would avoid the serious structural problems that small cracks might lead to. The resin travels through 40-micron wide areas within the tubes that seal the crack. One micron is one millionth of a meter, and a strand of hair is about one hundred microns in width! That’s tiny! This process is capable of sealing cracks within 90 minutes, which is about one Earth orbit.
Many people have also asked the question: “What happens when space satellites die?” Most of the time mission controllers are able to spot glitches and they immediately put the satellites in something called a “graveyard orbit” that puts it about several hundred miles above its previous orbit. This prevents it from colliding with its spacecraft and other satellites. When extreme cases occur, space satellites can and have been blasted and destroyed by missiles. An easier way to deal with dying satellites is to bring them back to Earth for repair. Another way that they have recently fixed damaged satellites is to send “robotic surgeons” into space to fix them. Although this method is very expensive, it definitely portrays the future of repairing satellites.
Satellites play a huge role in the lives of humans every day. Without them, life would be a lot harder. In 1997, there was a recorded number of around 25,000 manmade satellites in space! There were about 16,000 in decay and about 8,681 in orbit. Even within this statistic, not every satellite was included because some were too small or too far off to be detected from Earth. Satellites have proven to be very useful instruments that are capable of doing amazing things. Without satellites, we would not know nearly as much about the planets, space, or even Earth if it were not for them.
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