The History of Sputnik I and Its Effect on the U.S. By Mary Bellis Updated August 07, 2016. History was made on October 4, 1957 when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a basketball and weighed only 183 pounds. It took about 98 minutes for Sputnik I to orbit the Earth on its elliptical path. The launch ushered in new political, military, technological and scientific developments and marked the beginning of the space race between the U.S.and the U.S.S.R. The International Geophysical Year In 1952, the International Council of Scientific Unions decided to establish the International Geophysical Year. It wasn't actually a year but rather more like 18 months, set from July 1, 1957 to December 31, 1958. Scientists knew that cycles of solar activity would be at a high point at this time. The Council adopted a resolution in October 1954 calling for artificial satellites to be launched during the IGY to map the earth's surface. The U.S.

Contribution The White House announced plans to launch an earth-orbiting satellite for the IGY in July 1955. The government solicited proposals from various research agencies to undertake development of this satellite. NSC 5520, the Draft Statement of Policy on U.S. Scientific Satellite Program, recommended both the creation of a scientific satellite program as well as the development of satellites for reconnaissance purposes. The National Security Council approved the IGY satellite on May 26, 1955 based on NSC 5520. This event was announced to the public on July 28 during an oral briefing at the White House. The government's statement emphasized that the satellite program was intended to be the U.S. contribution to the IGY and that the scientific data was to benefit scientists of all nations. The Naval Research Laboratory's Vanguard proposal for a satellite was chosen in September 1955 to represent the U.S.during the IGY. Then Came Sputnik I The Sputnik launch changed everything. As a technical achievement, it caught the world's attention and the American public off guard. Its size was more impressive than Vanguard's intended 3.5-pound payload.

The public reacted with fear that the Soviets' ability to launch such a satellite would translate to the ability to launch ballistic missiles that could carry nuclear weapons from Europe to the U.S. Then the Soviets struck again: Sputnik II was launched on November 3, carrying a much heavier payload and a dog named Laika. The U.S. Response The U.S. Defense Department responded to the political and public furor over the Sputnik satellites by approving funding for another U.S. satellite project. As a simultaneous alternative to Vanguard, Wernher von Braun and his Army Redstone Arsenal team began work on a satellite that would become known as Explorer. The tide of the space race changed on January 31, 1958 when the U.S. successfully launched Satellite 1958 Alpha, familiarly known as Explorer I. This satellite carried a small scientific payload that eventually discovered magnetic radiation belts around the Earth. These belts were named after principal investigator James Van Allen. The Explorer program continued as a successful ongoing series of lightweight, scientifically-useful spacecraft. The Creation of NASA The Sputnik launch also led to the creation of NASA, the National Aeronautics and Space Administration.

Congress passed the National Aeronautics and Space Act, commonly called the "Space Act,” in July 1958, and the Space Act created NASA effective October 1, 1958. It joined NACA, the National Advisory Committee for Aeronautics, with other government agencies. NASA went on to do pioneering work in space applications, such as communications satellites, in the 1960s. The Echo, Telstar, Relay and Syncom satellites were built by NASA or by the private sector based on significant NASA advances. In the 1970s, NASA's Landsat program literally changed the way we look at our planet. The first three Landsat satellites were launched in 1972, 1975 and 1978. They transmitted complex data streams back to earth that could be converted into colored pictures. Landsat data has been used in a variety of practical commercial applications since then, including crop management and fault line detection. It tracks many kinds of weather, such as droughts, forest fires and ice floes.

NASA has also been involved in a variety of other earth science efforts as well, such as the Earth Observation System of spacecraft and data processing that has yielded important scientific results in tropical deforestation, global warming and climate change. Telstar: Satellites Beamed First TV Signals Across the Ocean Start Over | More Quizzes Lucky first try Fortunately, unlike other satellites of the time, Telstar 1 launched on the first try. It soared into space on July 10, 1962, from its launch pad at Cape Canaveral in Florida. The 34-inch (87 cm) spherical satellite, which weighed 171 pounds (77 kilograms), was inserted into an orbit of about 3,505 miles (5,640 kilometers) at its highest, and 903 miles (1,453 kilometers) at its lowest. This is quite different from the major communications satellites of today, which "hover" at one point above the surface in geosynchronous orbit , but bear in mind that this was a test. Telstar's first live television pictures in France — relayed only a few hours after launch, according to NASA — showed a U.S.

flag outside of a receiving station in Maine. The satellite was also equipped to handle telephone calls and even picture faxes, and had an experiment that could examine the radiation in the Van Allen belts above Earth. "Telstar was a tremendous technical success, and the international reaction was spectacular," NASA later wrote in "Beyond the Ionosphere." "A U.S. Information Agency (USIA) poll showed that Telstar was better known in Great Britain than Sputnik had been in 1957. Rather than launching a useless bauble, the Americans had put into orbit a satellite that promised to tie together the ears and eyes of the world." The satellite, in fact, was immortalized in a song in 1962. A British band called The Tornados created the song "Telstar," which hit No. 1 on the U.S. Billboard 100 at the height of its popularity.

Many years later, Susanna Hoff, lead singer of the Bangles, wrote a 1991 song that mentioned the satellite; it was called "Wishing on Telstar." Monopoly concerns Telstar 1 started to have transmission difficulties in November 1962, and eventually saw its transmitter fail in February 1963. Telstar 2 launched on May 7, 1963. It was practically a twin of Telstar 1, but in this case, the satellite lasted until it was turned off in 1965 — longer than its predecessor. AT&T had clearly demonstrated acumen in how to build and use a satellite. They already had a monopoly in the telephone business, and according to NASA, there were those that feared that the monopoly could extend into space as well. "AT&T's preeminent position as the largest U.S. common carrier and sole international telephone carrier, together with its willingness and ability to commit large sums of money to the development of communications satellites, convincingly suggested that commercial satellite utilization would very likely become AT&T utilization," NASA wrote. In August 1962, President John F. Kennedy approved the Communications Satellite Act .

This act had been in the works for several years. The act placed U.S. satellite communications under a federally supervised company (with joint participation from several U.S. firms) called the Communications Satellite Corporation, or Comsat. While AT&T was a participant in Comsat, this ensured that the company could not have a space-faring monopoly. Comsat was later a founder of an entity called Intelsat that focused on international satellite coverage. In 1970, the Federal Communications Commission — under the Open Skies Policy — opened up domestic satellite communications launches to all firms that were capable of doing it. Comsat and Intelsat still exist today, but under very different structures. October 4, 2007 marks the 50th anniversary of the launch of the manmade satellite. How well do you remember the past half-century in space? Take this 10-question quiz and test your knowledge of space history. Start Over | More Quizzes Telstar's legacy All in all, Telstar showed that the communications business was an area of great flux in the 1960s and 1970s.

The Telstar satellites ushered in an era where satellites turned from experimental machines to sophisticated systems with great value to the companies producing them. A new wave of advanced geosynchronous spacecraft shares the Telstar name, but these commercial satellites are far more advanced than their predecessors. Telstar 301 launched in 1983, followed by Telstar 302 in 1984. Telstar 302, renamed Telstar 3C, was put into orbit by a Space shuttle Discovery crew. A dozen more satellites bearing the Telstar name have since been launched. Telstar 1 is still in orbit , as of February 2013, but it is no longer functional. — Elizabeth Howell, SPACE.com Contributor Communications Satellites Short History COMMUNICATIONS SATELLITES SHORT HISTORY Global Village Possible by David J. Whalen In 500 years, when humankind looks back at the dawn of space travel, Apollo's landing on the Moon in 1969 may be the only event remembered. At the same time, however, Lyndon B. Johnson, himself an avid promoter of the space program, felt that reconnaissance satellites alone justified every penny spent on space.

Weather forecasting has undergone a revolution because of the availability of pictures from geostationary meteorological satellites--pictures we see every day on television. All of these are important aspects of the space age, but satellite communications has probably had more effect than any of the rest on the average person. Satellite communications is also the only truly commercial space technology- -generating billions of dollars annually in sales of products and services. The Billion Dollar Technology In fall of 1945 an RAF electronics officer and member of the British Interplanetary Society, Arthur C. Clarke, wrote a short article in Wireless World that described the use of manned satellites in 24-hour orbits high above the world's land masses to distribute television programs. His article apparently had little lasting effect in spite of Clarke's repeating the story in his 1951/52 The Exploration of Space . Perhaps the first person to carefully evaluate the various technical options in satellite communications and evaluate the financial prospects was John R.

Pierce of AT&T's Bell Telephone Laboratories who, in a 1954 speech and 1955 article, elaborated the utility of a communications "mirror" in space, a medium-orbit "repeater" and a 24-hour-orbit "repeater." In comparing the communications capacity of a satellite, which he estimated at 1,000 simultaneous telephone calls, and the communications capacity of the first trans-atlantic telephone cable (TAT-1), which could carry 36 simultaneous telephone calls at a cost of 30-50 million dollars, Pierce wondered if a satellite would be worth a billion dollars. After the 1957 launch of Sputnik I, many considered the benefits, profits, and prestige associated with satellite communications. Because of Congressional fears of "duplication," NASA confined itself to experiments with "mirrors" or "passive" communications satellites (ECHO), while the Department of Defense was responsible for "repeater" or "active" satellites which amplify the received signal at the satellite--providing much higher quality communications.

In 1960 AT&T filed with the Federal Communications Commission (FCC) for permission to launch an experimental communications satellite with a view to rapidly implementing an operational system. The U.S. government reacted with surprise-- there was no policy in place to help execute the many decisions related to the AT&T proposal. By the middle of 1961, NASA had awarded a competitive contract to RCA to build a medium-orbit (4,000 miles high) active communication satellite (RELAY); AT&T was building its own medium-orbit satellite (TELSTAR) which NASA would launch on a cost-reimbursable basis; and NASA had awarded a sole- source contract to Hughes Aircraft Company to build a 24-hour (20,000 mile high) satellite (SYNCOM). The military program, ADVENT, was cancelled a year later due to complexity of the spacecraft, delay in launcher availability, and cost over-runs. By 1964, two TELSTARs, two RELAYs, and two SYNCOMs had operated successfully in space.

This timing was fortunate because the Communications Satellite Corporation (COMSAT), formed as a result of the Communications Satellite Act of 1962, was in the process of contracting for their first satellite. COMSAT's initial capitalization of 200 million dollars was considered sufficient to build a system of dozens of medium-orbit satellites. For a variety of reasons, including costs, COMSAT ultimately chose to reject the joint AT&T/RCA offer of a medium-orbit satellite incorporating the best of TELSTAR and RELAY. They chose the 24-hour-orbit (geosynchronous) satellite offered by Hughes Aircraft Company for their first two systems and a TRW geosynchronous satellite for their third system. On April 6, 1965 COMSAT's first satellite, EARLY BIRD, was launched from Cape Canaveral. Global satellite communications had begun. The Global Village: International Communications Some glimpses of the Global Village had already been provided during experiments with TELSTAR, RELAY, and SYNCOM. These had included televising parts of the 1964 Tokyo Olympics. Although COMSAT and the initial launch vehicles and satellites were American, other countries had been involved from the beginning.

AT&T had initially negotiated with its European telephone cable "partners" to build earth stations for TELSTAR experimentation. NASA had expanded these negotiations to include RELAY and SYNCOM experimentation. By the time EARLY BIRD was launched, communications earth stations already existed in the United Kingdom, France, Germany, Italy, Brazil, and Japan. Further negotiations in 1963 and 1964 resulted in a new international organization, which would ultimately assume ownership of the satellites and responsibility for management of the global system. On August 20, 1964, agreements were signed which created the International Telecommunications Satellite Organization (INTELSAT). By the end of 1965, EARLY BIRD had provided 150 telephone "half- circuits" and 80 hours of television service. The INTELSAT II series was a slightly more capable and longer-lived version of EARLY BIRD. Much of the early use of the COMSAT/INTELSAT system was to provide circuits for the NASA Communications Network (NASCOM). The INTELSAT III series was the first to provide Indian Ocean coverage to complete the global network.

This coverage was completed just days before one half billion people watched APOLLO 11 land on the moon on July 20, 1969. From a few hundred telephone circuits and a handful of members in 1965, INTELSAT has grown to a present-day system with more members than the United Nations and the capability of providing hudreds of thousands of telephone circuits. Cost to carriers per circuit has gone from almost $100,000 to a few thousand dollars. Cost to consumers has gone from over $10 per minute to less than $1 per minute. If the effects of inflation are included, this is a tremendous decrease! INTELSAT provides services to the entire globe, not just the industrialized nations. Hello Guam: Domestic Communications In 1965, ABC proposed a domestic satellite system to distribute television signals. The proposal sank into temporary oblivion, but in 1972 TELESAT CANADA launched the first domestic communications satellite, ANIK, to serve the vast Canadian continental area. RCA promptly leased circuits on the Canadian satellite until they could launch their own satellite. The first U.S.

domestic communications satellite was Western Union's WESTAR I, launched on April 13, 1974. In December of the following year RCA launched their RCA SATCOM F- 1. In early 1976 AT&T and COMSAT launched the first of the COMSTAR series. These satellites were used for voice and data, but very quickly television became a major user. By the end of 1976 there were 120 transponders available over the U.S., each capable of providing 1500 telephone channels or one TV channel. Very quickly the "movie channels" and "super stations" were available to most Americans. The dramatic growth in cable TV would not have been possible without an inexpensive method of distributing video. The ensuing two decades have seen some changes: Western Union is no more; Hughes is now a satellite operator as well as a manufacturer; AT&T is still a satellite operator, but no longer in partnership with COMSAT; GTE, originally teaming with Hughes in the early 1960s to build and operate a global system is now a major domestic satellite operator.

Television still dominates domestic satellite communications, but data has grown tremendously with the advent of very small aperture terminals (VSATs). Small antennas, whether TV-Receive Only (TVRO) or VSAT are a commonplace sight all over the country. New Technology The first major geosynchronous satellite project was the Defense Department's ADVENT communications satellite. It was three-axis stabilized rather than spinning. It had an antenna that directed its radio energy at the earth. It was rather sophisticated and heavy. At 500-1000 pounds it could only be launched by the ATLAS- CENTAUR launch vehicle. ADVENT never flew, primarily because the CENTAUR stage was not fully reliable until 1968, but also because of problems with the satellite. When the program was canceled in 1962 it was seen as the death knell for geosynchronous satellites, three-axis stabilization, the ATLAS-CENTAUR, and complex communications satellites generally. Geosynchronous satellites became a reality in 1963, and became the only choice in 1965. The other ADVENT characteristics also became commonplace in the years to follow.

In the early 1960s, converted intercontinental ballistic missiles (ICBMs) and intermediate range ballistic missiles (IRBMs) were used as launch vehicles. These all had a common problem: they were designed to deliver an object to the earth's surface, not to place an object in orbit. Upper stages had to be designed to provide a delta-Vee (velocity change) at apogee to circularize the orbit. The DELTA launch vehicles, which placed all of the early communications satellites in orbit, were THOR IRBMs that used the VANGUARD upper stage to provide this delta-Vee. It was recognized that the DELTA was relatively small and a project to develop CENTAUR, a high-energy upper stage for the ATLAS ICBM, was begun. ATLAS-CENTAUR became reliable in 1968 and the fourth generation of INTELSAT satellites used this launch vehicle. The fifth generation used ATLAS-CENTAUR and a new launch-vehicle, the European ARIANE. Since that time other entries, including the Russian PROTON launch vehicle and the Chinese LONG MARCH have entered the market. All are capable of launching satellites almost thirty times the weight of EARLY BIRD.

In the mid-1970s several satellites were built using three-axis stabilization. They were more complex than the spinners, but they provided more despun surface to mount antennas and they made it possible to deploy very large solar arrays. The greater the mass and power, the greater the advantage of three-axis stabilization appears to be. Perhaps the surest indication of the success of this form of stabilization was the switch of Hughes, closely identified with spinning satellites, to this form of stabilization in the early 1990s. The latest products from the manufacturers of SYNCOM look quite similar to the discredited ADVENT design of the late 1950s. Much of the technology for communications satellites existed in 1960, but would be improved with time. The basic communications component of the satellite was thr traveling-wave-tube (TWT). These had been invented in England by Rudoph Kompfner, but they had been perfected at Bell Labs by Kompfner and J. R. Pierce. All three early satellites used TWTs built by a Bell Labs alumnus. These early tubes had power outputs as low as 1 watt.

Higher- power (50-300 watts) TWTs are available today for standard satellite services and for direct-broadcast applications. An even more important improvement was the use of high-gain antennas. Focusing the energy from a 1-watt transmitter on the surface of the earth is equivalent to having a 100-watt transmitter radiating in all directions. Focusing this energy on the Eastern U.S. is like having a 1000-watt transmitter radiating in all directions. The principal effect of this increase in actual and effective power is that earth stations are no longer 100-foot dish reflectors with cryogenically-cooled maser amplifiers costing as much as $10 million (1960 dollars) to build. Antennas for normal satellite services are typically 15-foot dish reflectors costing $30,000 (1990 dollars). Direct-broadcast antennas will be only a foot in diameter and cost a few hundred dollars. Mobile Services In February of 1976 COMSAT launched a new kind of satellite, MARISAT, to provide mobile services to the United States Navy and other maritime customers.

In the early 1980s the Europeans launched the MARECS series to provide the same services. In 1979 the UN International Maritime Organization sponsored the establishment of the International Maritime Satellite Organization (INMARSAT) in a manner similar to INTELSAT. INMARSAT initially leased the MARISAT and MARECS satellite transponders, but in October of 1990 it launched the first of its own satellites, INMARSAT II F-1. The third generation, INMARSAT III, has already been launched. An aeronautical satellite was proposed in the mid-1970s. A contract was awarded to General Electric to build the satellite, but it was canceled--INMARSAT now provides this service. Although INMARSAT was initially conceived as a method of providing telephone service and traffic-monitoring services on ships at sea, it has provided much more. The journalist with a briefcase phone has been ubiquitous for some time, but the Gulf War brought this technology to the public eye. The United States and Canada discussed a North American Mobile Satellite for some time.

In the next year the first MSAT satellite, in which AMSC (U.S.) and TMI (Canada) cooperate, will be launched providing mobile telephone service via satellite to all of North America. Competition In 1965, when EARLY BIRD was launched, the satellite provided almost 10 times the capacity of the submarine telephone cables for almost 1/10th the price. This price-differential was maintained until the laying of TAT-8 in the late 1980s. TAT-8 was the first fiber-optic cable laid across the Atlantic. Satellites are still competitive with cable for point-to-point communications, but the future advantage may lie with fiber-optic cable. Satellites still maintain two advantages over cable: they are more reliable and they can be used point-to-multi-point (broadcasting). Cellular telphone systems have risen as challenges to all other types of telephony. It is possible to place a cellular system in a developing country at a very reasonable price. Long-distance calls require some other technology, but this can be either satellites or fiber-optic cable. The LEO Systems Cellular telephony has brought us a new technological "system"-- the personal communications system (PCS).

In the fully developed PCS, the individual would carry his telephone with him. This telephone could be used for voice or data and would be usable anywhere. Several companies have committed themselves to providing a version of this system using satellites in low earth orbits (LEO). These orbits are significantly lower than the TELSTAR/RELAY orbits of the early 1960s. The early "low-orbit" satellites were in elliptical orbits that took them through the lower van Allen radiation belt. The new systems will be in orbits at about 500 miles, below the belt. The most ambitious of these LEO systems is Iridium, sponsored by Motorola. Iridium plans to launch 66 satellite into polar orbit at altitudes of about 400 miles. Each of six orbital planes, separated by 30 degrees around the equator, will contain eleven satellites. Iridium originally planned to have 77 satellites-- hence its name. Element 66 has the less pleasant name Dysprosium. Iridium expects to be providing communications services to hand- held telephones in 1998. The total cost of the Iridium system is well in excess of three billion dollars.

In addition to the "Big LEOS" such as Iridium and Globalstar, there are several "little leos." These companies plan to offer more limited services, typically data and radiodetermination. Typical of these is ORBCOM which has already launched an experimental satellite and expects to offer limited service in the very near future. Prospect and Retrospect Arthur C. Clarke's 1945 vision was of a system of three "manned" satellites located over the major land masses of the earth and providing direct-broadcase television. The inherent "broadcast" nature of satellite communications has made direct-broadcast a recurrent theme--yet one never brought to fruition. The problems are not technical--they are political, social, and artistic. What will people be willing to pay for? This is the question-- especially with the availability of 120-channel cable systems. Hughes is apparently about to enter this field and may encourage others to do the same. Only then will Clarke's prophetic vision be fulfilled. There are currently six companies providing fixed satellite service to the U.S.: GE Americom, Alascom, AT&T, COMSAT, GTE, and Hughes Communications.

They operate 36 satellites with a net worth of over four billion dollars. The gound stations which communicate with these satellites are innumerable and may have a similar net worth. INTELSAT has had competition in the international market from Pan American Satellite since 1986. Orion Satellite is expected to begin international service in 1994. Since Canada began domestic satellite service in 1972, that country has been joined by the United States (1974), Indonesia (1976), Japan (1978), India (1982), Australia (1985), Brazil (1985), Mexico (1985), and many others. Each year from 10-20 communications satellites are launched valued at about $75 million each. The launch vehicles placing them in orbit have similar values. Both satellites and launch vehicles are multi-billion dollar businesses. The earth station business is equally large. Finally the communications services themselves are multi-billion dollar businesses. John R. Pierce was right--it would be worth a billion dollars. A Selective Communications Satellite Chronology 1945 Arthur C.

Clarke Article: "Extra-Terrestrial Relays" 1955 John R. Pierce Article: "Orbital Radio Relays" 1956 First Trans-Atlantic Telephone Cable: TAT-1 1957 Sputnik: Russia launches the first earth satellite. 1960 1st Successful DELTA Launch Vehicle 1960 AT&T applies to FCC for experimental satellite communications license 1961 Formal start of TELSTAR, RELAY, and SYNCOM Programs 1962 TELSTAR and RELAY launched 1962 Communications Satellite Act (U.S.) 1963 SYNCOM launched 1965 COMSAT's EARLY BIRD: 1st commercial communications satellite 1969 INTELSAT-III series provides global coverage 1972 ANIK: 1st Domestic Communications Satellite (Canada) 1974 WESTAR: 1st U.S. Domestic Communications Satellite 1975 INTELSAT-IVA: 1st use of dual-polarization 1975 RCA SATCOM: 1st operational body-stabilized comm.

satellite 1976 MARISAT: 1st mobile communications satellite 1976 PALAPA: 3rd country (Indonesia) to launch domestic comm. satellite 1979 INMARSAT formed. How do satellites work? - Explain that Stuff Tweet by Chris Woodford . Last updated: August 5, 2016. Eyes in the sky, space mirrors bouncing phone calls round Earth, heavenly compasses helping us home—these are just three of the things that satellites do for us. When you gaze through the clouds on a brilliant blue day, you might catch sight of a plane or two leaving vapor trails in its wake. But you're unlikely to see all the thousands of meticulously engineered satellites, some as small as your hand , some as huge as trucks, spinning in orbits high above your head. "Out of sight, out of mind" is probably one of the reasons we take satellites for granted, even though they play a crucial part in everything from TV broadcasting and transcontinental telephone calls to weather forecasting and the Internet. What exactly is a satellite and how does it work? Let's take a closer look! Photo: A typical communications satellite from the 1980s.

The blue squares are solar panels that provide power. The white circles are the sending and receiving antennas . Picture courtesy of NASA Glenn Research Center (NASA-GRC) . What is a satellite? A satellite doesn't necessarily have to be a tin can spinning through space. The word "satellite" is more general than that: it means a smaller, space-based object moving in a loop (an orbit) around a larger object. The Moon is a natural satellite of Earth, for example, because gravity locks it in orbit around our planet. The tin cans we think of as satellites are actually artificial (human-built) satellites that move in precisely calculated paths, circular or elliptical (oval), at various distances from Earth, usually well outside its atmosphere. Photo: The Space Shuttle launches a communications satellite from its payload bay in 1984 by spinning it gyroscopically. You can see Earth to the left. Picture courtesy of NASA Johnson Space Center (NASA-JSC) . We put satellites in space to overcome the various limitations of Earth's geography—it helps us step outside our Earth-bound lives.

If you want to make a phone call from the North Pole, you can fire a signal into space and back down again, using a communications satellite as a mirror to bounce the signal back to Earth and its destination. If you want to survey crops or ocean temperatures, you could do it from a plane, but a satellite can capture more data more quickly because it's higher up and further away. Similarly, if you want to drive somewhere you've never been before, you could study maps or ask random strangers for directions, or you could use signals from satellites to guide you instead. Satellites, in short, help us live within Earth's limits precisely because they themselves sit outside them. What do satellites do for us? We tend to group satellites either according to the jobs they do or the orbits they follow. These two things are, however, very closely related, because the job a satellite does usually determines both how far away from Earth it needs to be, how fast it has to move, and the orbit it has to follow. The three main uses of satellites are for communications; photography, imaging, and scientific surveying; and navigation.

Communications Communications satellites are essentially used to relay radio waves from one place on Earth to another, catching signals that fire up to them from a ground station (an Earth-based satellite dish), amplifying them so they have enough strength to continue (and modifying them in other ways), and then bouncing them back down to a second ground station somewhere else. Those signals can carry anything radio signals can carry on the ground, from telephone calls and Internet data to radio and TV broadcasts. Communications satellites essentially overcome the problem of sending radio waves, which shoot in straight lines, around our curved planet—intercontinental signals, in other words. They're also useful for communicating to and from remote areas where ordinary wired or wireless communications can't reach. Calling with a traditional landline (wired phone), you need a very convoluted network of wires and exchanges to make a complete physical circuit all the way from the sender to the receiver; with a cellphone , you can communicate anywhere you can get a signal, but you and the receiver both still need to be within range of cellphone masts; however, with a satellite phone, you can be on top of Mount Everest or deep in the Amazon jungle.

You're entirely free from any kind of telecommunications "infrastructure," which gives you geographic freedom and an instant ability to communicate (you don't have to wait for someone to string up telephone lines or set up cellphone masts). The best known modern communications satellite systems are probably INMARSAT and INTELSAT. INMARSAT was originally a satellite system for ships, planes, and other travelers, though it now has many other uses as well. INTELSAT is an international consortium that owns and operates several dozen communications satellites that provide things like international broadcasting and satellite broadband Internet. How do communications satellites work? What do they do? Communications satellites are "space mirrors" that can help us bounce radio, TV, Internet data, and other kinds of information from one side of Earth to the other. Uplinks and downlinks If you want to send something like a TV broadcast from one side of Earth to the other, there are three stages involved. First, there's the uplink, where data is beamed up to the satellite from a ground station on Earth. Next, the satellite processes the data using a number of onboard transponders (radio receivers, amplifiers, and transmitters).

These boost the incoming signals and change their frequency, so incoming signals don't get confused with outgoing ones. Different transponders in the same satellite are used to handle different TV stations carried on different frequencies. Finally, there's the downlink, where data is sent back down to another ground station elsewhere on Earth. Although there's usually just a single uplink, there may be millions of downlinks, for example, if many people are receiving the same satellite TV signal at once. While a communications satellite might relay a signal between one sender and receiver (fired up into space and back down again, with one uplink and one downlink), satellite broadcasts typically involve one or more uplinks (for one or more TV channels) and multiple downlinks (to ground stations or individual satellite TV subscribers). Artwork: Communications satellites bounce signals from one side of Earth to the other, a bit like giant mirrors in space. A ground-based satellite transmitter dish (red) beams a signal to the satellite's receiving dish (yellow). The satellite boosts the signal and sends it back down to Earth from its transmitter dish (red) to a receiving dish somewhere else on Earth (yellow).

Since the whole process happens using radio waves, which travel at the speed of light , a "satellite relay" of this kind usually takes no more than a few seconds, at most. The various transmitters and receivers on the satellite and on Earth are examples of antennas . Satellites are like any other vehicle inasmuch as they have two main parts: the generic vehicle itself and the specific thing it carries (the payload) to do its unique job. The "vehicle" part of a satellite is called the bus, and it includes the outer case, the solar panels and batteries that provide power, telemetry (a remote-controlled system that sends monitoring data from the satellite to Earth and operational commands back in the other direction), rocket thrusters to keep it in position, and reflective materials or other systems ("heat pipes") to protect it from solar radiation and dissipate heat. The payload might include transponders for a communications satellite, computers and atomic clocks to generate time signals for a navigation satellite, cameras and computers to images back to digital data for a photographic satellite, and so on. What's inside a satellite?

These are amazingly complex and expensive machines with tons of electronic bits and pieces jammed into them, but let's not get too bogged down in the details: the basic idea is very simple. In this outside view of a typical satellite, from a patent filed in 1968 by German engineer Hans Sass ( US Patent: #3,559,919: Active communication satellite ), you can see all the main bits and it's easy to figure out what they do. I've left the original numbers on the diagram and I won't bother to label them all, since some are obvious and some are duplicates of others. The most interesting bits are the fold-out solar panels that power the satellite, the sending and receiving antennas that collect signals coming up from Earth and send them back down, and the motors and engines that keep the satellite in exactly the right position at all times: 4: Large parabolic dish antenna for sending/receiving signals. (Orange) 5: Small parabolic dish antenna for sending/receiving signals. (Orange) 6: Lower solar "battery" of four solar panels. (Red) 7: Upper solar "battery" of four more solar panels.

(Red) 8: Supports fold out the lower solar panels once the satellite is in orbit. (Gray-brown) 9: Supports fold out the upper solar panels. (Gray-brown) 10: Main satellite rocket motor. (Light blue) 11, 12, 15, 17: Small control engines keep the satellite in its precision position, spin, and orbit. (Green) Artwork from US Patent: #3,559,919: Active communication satellite, courtesy of US Patent and Trademark Office. Photography, imaging, and scientific surveying Photo: Satellite photography has revolutionized map-making. This is Havana, Cuba photographed by the Landsat satellite. Picture courtesy of NASA Landsat program . Not so many years ago, newspapers used to run scare stories about spy satellites high in space that could read newspapers over your shoulder. These days, we all have access to satellite photos, albeit not quite that detailed: they're built into search engines like Google and Bing, and they feature routinely on the news (giving us an instant visual impression of things like disappearing rainforests or tsunami destruction ) and weather forecasts.

Scientific satellites work in a similar way to photographic ones but, instead of capturing simple visual images, systematically gather other kinds of data over vast areas of the globe. There have been many interesting scientific satellite missions over the last few decades. NASA's TOPEX/Poseidon and Jason satellites, for example, have routinely measured sea levels since the early 1990s. SeaWiFS (active until 2010) scanned the color of the ocean to measure plankton and nutritional activity in the sea. As its name suggests, a weather satellite called TRMM (Tropical Rainfall Measuring Mission) monitored rain near the equator from 1997 through 2015. As of 2016, NASA listed 25 ongoing satellite missions on its website, including CALIPSO (which studies how clouds and aerosols interact); Nimbus (a long-running scientific study of weather and climate using satellite data); and, the longest-running and perhaps best known scientific satellites of all-time, Landsat , a series of eight satellites that have been continuously mapping and monitoring changes in land use across Earth since 1972.

Navigation Finally, most of us with GPS-enabled cellphones and "sat-nav" devices in our cars are familiar with the way satellites act like sky compasses; you'll find GPS, Glonass, and similar systems discussed in much more detail in our article about satellite navigation . Photo: Where am I, where am I going, and how will I get there? Most of us with smartphones take satellite navigation for granted. Satellite orbits One of the most surprising things about satellites is the very different paths they follow at very different heights above Earth. Left to its own devices, a satellite fired into space might fall back to Earth just like a stone tossed into the air. To stop that happening, satellites have to keep moving all the time so, even though the force of gravity is pulling on them, they never actually crash back to Earth. Some turn at the same rotational rate as Earth so they're effectively fixed in one position above our heads; others go much faster. Although there are many different types of satellite orbits, they come in three basic varieties, low, medium, and high—which are short, medium, and long distances above Earth, respectively.

Low-Earth orbits Scientific satellites tend to be quite close to Earth—often just a few hundred kilometers up—and follow an almost circular path called a low-Earth orbit (LEO). Since they have to be moving very fast to overcome Earth's gravity, and they have a relatively small orbit (because they're so close), they cover large areas of the planet quite quickly and never stay over one part of Earth for more than a few minutes. Some follow what's called a polar orbit, passing over both the North and South poles in a "loop" taking just over an hour and a half to complete. Medium-earth orbits The higher up a satellite is, the longer it spends over any one part of Earth. It's just the same as jet planes flying over your head: the slower they move through the sky, the higher up they are. A medium-Earth orbit (MEO) is about 10 times higher up than a LEO. GPS navstar satellites are in MEO orbits roughly 20,000 km (12,000 miles) above our heads and take 12 hours to "loop" the planet.

Their orbits are semi-synchronous, which means that, while they're not always exactly in the same place above our heads, they pass above the same points on the equator at the same times each day. High-Earth orbits Many satellites have orbits at a carefully chosen distance of about 36,000 km (22,000 miles) from the surface. This "magic" position ensures they take exactly one day to orbit Earth and always return to the same position above it, at the same time of day. A high-Earth orbit like this is called geosynchronous (because it's synchronized with Earth's rotation) or geostationary (if the satellite stays over the same point on Earth all the time). Communications satellites—our "space mirrors"—are usually parked in geostationary orbits so their signals always reach the satellite dishes pointing up at them.

Weather satellites often use geostationary orbits because they need to keep gathering cloud or rainfall images from the same broad part of Earth from hour to hour and day to day (unlike LEO scientific satellites, which gather data from many different places over a relatively short period of time, geostationary weather satellites gather their data from a smaller area over a longer period of time). Who invented satellites? The idea of using a satellite as a mirror in space—to bounce signals from one side of Earth to the other—was "launched" in 1945 by science fiction author Arthur C. Clarke (1917–2008), who wrote two hugely influential articles setting out his plan in detail (one was unpublished, the other published as "Extra-Terrestrial Relays: Can Rocket Stations Give World-Wide Radio Coverage?" in Wireless World, October 1945). His proposal was to place three satellites in a geosynchronous orbit 35,000km (23,000 miles) above Earth, spaced out evenly to cover about a third of the planet each: one would cover Africa and Europe, a second would cover China and Asia, and a third would be dedicated to the Americas.

Although Clarke didn't patent the geostationary communications satellite, he is generally credited with its invention, even though other space pioneers (notably German wartime pioneer Herman Oberth ) had proposed similar ideas years before. It took another decade for Clarke's bold plan to move toward reality. First, satellites themselves had to be proved viable; that happened with the launch of the Russian Sputnik 1 in October 1957. Three years later, when the Echo communications satellite was launched, engineers successfully demonstrated that radio telecommunications signals could be relayed into space and back, just as Clarke had predicted. Telstar , the first communications satellite, was launched in July 1962 and immediately revolutionized transatlantic telecommunications. During the mid-1960s, 11 nations came together to form INTELSAT (International Telecommunications Satellite Consortium), which launched the world's first commercial communications satellite INTELSAT 1 ("Early Bird"), in geosychronous orbit, in April 1965. This modest little space machine was a tiny electronic miracle: weighing just 35kg (76 lb), it could transmit 240 telephone simultaneous calls or a single black-and-white TV channel.

Photo: Echoes of history: Designed by NASA, the Echo communications satellite was a giant mylar balloon some 30m (100ft) in diameter designed to sit in space and bounce signals back like a mirror. You can see how big it is from the size of the car and people at the bottom, which I've colored red to help you pick them out. Picture courtesy of NASA on The Commons . Telephones On other websites Exploring the Unknown: Selected Documents in the History of the U.S. Civil Space Program: Volume III: Using Space : Edited by John M. Logsdon with Roger D. Launius, David H. Onkst, and Stephen J. Garber. A good overview of satellite history, including Arthur C. Clarke's original two groundbreaking papers. [PDF format] Books Red Moon Rising: Sputnik and the Rivalries That Ignited the Space Age by Matthew Brzezin. Bloomsbury, 2007. An entertaining account of how satellites ignited competition between the United States and the Soviet Union. Satellite Communications Systems: Systems, Techniques and Technology by Gérard Maral, Michel Bousquet, and Zhili Sun.

Wiley, 2009. A detailed technical introduction to space satellites. Articles Potential Eyes in the Sky on Greenhouse Gases by William J. Broad. The New York Times, May 9, 2016. Scientists are calling for a new network of scientific satellites that can monitor carbon dioxide emissions more precisely. 9 Earth-Imaging Start-ups to Watch by Jean Kumagai. IEEE Spectrum, March 28, 2014. Looks at examples of new commercial satellites that are offering ever-better ways to study what's happening on Earth. Microsatellites: What Big Eyes They Have by Anne Eisenberg. The New York Times, August 10, 2013. The latest generation of tiny satellites open up new business opportunities—and privacy concerns. How satellites could 'sail' home by Jonathan Amos, BBC News, 3 May 2009. How satellites and space rockets could return to Earth using sails as aero-brakes. Why the spy satellite won't fall on your head by Kathryn Westcott, BBC News, 28 January 2008. What happens to an old satellite when it reaches the end of its useful life?

Patents For those of you interested in deeper technical detail, here are a few representative examples of patented satellite designs from the last few decades: Scientific satellite: US Patent: 2,835,548: Satellite structure by Robert Baumann, May 20, 1958, assigned to the US Navy. Describes a scientific satellite that can carry sensors into Earth's atmosphere to make remote, automated measurements. Navigation satellite: US Patent: 4,445,118: Navigation system and method by Ralph E. Taylor and James W. Sennott, April 24, 1984, assigned to NASA. Describes some of the technical details of the NAVSTAR Global Positioning System (GPS). Communications satellite: US Patent: 3,710,255: Satellite communication system by Francis Gicca, January 9, 1973, assigned to Raytheon. Describes uplinks, downlinks, and satellite relays in quite a bit more detail than I've done above. Scientific satellite: US Patent: 4,611,929: Satellite method for measuring sea surface temperature by Ronald J.

Holyer, September 16, 1986, assigned to the US Navy. Describes a way of measuring sea temperatures from space using two satellites (one geostationary and another in polar orbit). Satellite television: US Patent: 4,381,562: Broadcast type satellite communication systems by Anthony Acampora, April 26, 1983, assigned to Bell Labs. Describes a typical satellite TV broadcasting system using a small number of uplinks (from TV stations) and a much larger number of downlinks (to individual subscribers). Satellite images of Earth Satellite Facts and Information :: Radio-Electronics.Com Satellite facts and information - a potpourri of interesting and not so interesting satellite facts and information. There are many satellites in orbit fulfilling a huge variety of functions. Satellite technology has now become a part of everyday life, enabling worldwide communications, global navigation, surveying and monitor as well as gathering data for weather forecasting, and many more applications. There are many facts associated with satellites that are both interesting and useful. Often the facts about these satellites and satellites in general may not be obvious. We have compiled a page of interesting satellite facts as an introduction to satellite technology.

Please read some of our other satellite pages to gain more of an insight into satellite technology in general. Facts about numbers of satellites in orbit Fact Over 2 500 in orbit around the Earth First rockets that entered outer space The German V2 rocket in mid 1940s Number of man-made objects orbiting the Earth In excess of 10 000 Facts about satellite firsts Details First fictional depiction of satellite The first mention of the idea of a satellite in a fictionals tory occurred in a short story by Edward Everett Hale, The Brick Moon. This story appeared in a publications entitled" The Atlantic Monthly". The serialisation started in 1869 First treatise on the use of satellites The idea of a satellite was first postulated Konstantin Tsiolkovsky (1857-1935). In 1903 he published an academic paper entitled: " Means of Reaction Devices." In this he proposed the idea of a multi-stage rocket using liquid hydrogen and oxygen being used to launch the satellite into orbit as well as calculating the orbital speed required to maintain orbit as 8 km/s.

First concept of a space station This occurred in 1928 when the Slovenian scientist, Herman Potocnik (1892-1929) published a book entitled: "The Problem of Space Travel - The Rocket Motor." In this he devised a scheme for establishing a permanent human presence in space. He developed the concept for the space station in some detail and calculated its geostationary orbit. He then went on to describe the use of orbiting spacecraft for observation of the ground for both commercial and military applications. First detailed concept of geostationary communications satellites This appeared in an article in 1945 in a British magazine entitled Wireless World. Although written by the famous English science fiction writer Arthur C. Clarke (1917-2008) it postulated the concept of communications satellites to be used for mass communications. Clarke investigated many aspects of the system from the satellite launch, possible orbits and other aspects of the creation of a network of world-circling satellites. He also correctly suggested that just three geostationary satellites would provide coverage over the entire planet.

Unfortunately he did not realise quite how much the system would be used, and that many more satellites would be required to cater for the huge volume of data. First satellites Sputnik 1 was launched by the Soviet Union on 4th October 1957. It was a football sized globe that transmitted a "beep beep" sound as it orbited the Earth. The word Sputnik means satellite. It continued transmitting for about 21 days. Second satellite Explorer 1 launched 31st January 1958 by USA. First passive reflector satellite Echo 1 - launched by the USA on 12 August 1960. It was used as a large reflector for radio signals, and was also plainly visible from Earth to the naked eye First active repeater communications satellite Courier 1B - this was launched on 4 October 1960. It was also the first satellite powered by solar cells that were used to re-charge batteries used to power the system when behind the earth. First direct relay communications satellite Telstar 1 - launched on 10 July 1962, it carried the first transatlantic live television pictures via satellite.

It was also used for telephone and high speed data communications. First communications satellite in geostationary orbit Syncom 2. This was launched on 19 August 1964. It carried the first Olympic broadcasts to international audiences via satellite. These Olympics were held in Tokyo. Details Geostationary orbit An orbit in which the satellite has the same angular velocity as the Earth so it appears above the same position above the Earth at all times. These orbits can only be directly above the equator. Geostationary orbit altitude Approximately 35 786 km, 22 236 mile Geostationary orbital velocity Approximately 3.07 km/s, 1.91 miles/s Geostationary orbital period 1 sidereal day, 23.934461223 hours, 23 hours 56 minutes and 4 seconds, 1 436 minutes 4 seconds.

Geostationary orbit distance The distance around the path of a complete geostationary orbit is approximately 265 000 km or 165 000 miles Low Earth Orbit, LEO altitude range 200 - 1200 km Medium Earth Orbit, MEO altitude range 1200 - 35790 km High Earth Orbit, HEO altitudes Above 35790 km

Question: What was the name of the first satellite to relay live TV pictures between the USA and Europe?
Answer: Telstar