Connecting the Planets

One wonders how a simple apple that “almost” fell on someone’s head, led to satellite constellations of today! The story of satellites is indeed a testimony to man’s intelligence and vision.

Many years, 43 to be precise, have passed since we launched our first satellite. Today, it is used for a variety of applications–providing communications links, data transfer, TV broadcasting, weather forecasting, navigation, surveillance, and the Internet, etc. The list is endless. It is the only means of communications, which can provide communications anytime and anywhere. Used in our everyday lives, satellite will continue to improve life on

earth.

In the next century, the satellites launched for interplanetary missions will help us in better understanding the intricate and fantastic mysteries of the universe. And the day is not far away when different planets might be used for entertainment or habitation purposes. 

1687: Legend says that Sir Issac Newton was sitting under an apple tree when an apple fell and hit him on the head causing him to come up with the idea of gravity. Actually, the apple missed him and made a soft thud on the ground. But that was enough to attract Newton’s attention. The apple’s fall triggered the important realization that a force–gravity–attracts all bodies in the universe towards each other, pulling apples to the ground and holding the moon and the planets in their orbits. In 1729, two years after his death, a book containing Newton’s theories was published. In it, Newton showed how an artificial satellite could be launched from the earth. He pictured the earth with a high mountain and a cannon on the top of the mountain firing shots parallel to the ground. Each time the cannon was fired, more gunpowder was used and the shot went farther before striking the ground. Because the earth is round, the shots curved around it. According to Newton’s theory, with enough gunpowder, a shot could eventually go fast enough to circle the earth completely and come back to the mountain top.

1869: Edward Everett Hale publishes a book called “The Brick Moon” which talks about an artificial satellite placed in an orbit as a navigational aid.

1896: Konstantin Tsiolkovsky forecasted many features of modern astronautics. He wrote science fiction accounts on space adventure in which he accurately described artificial satellites. Some of these works include “On the Moon”, “Dreams of the Earth and the Sky” and “Beyond the Earth”. He designed a multi-stage rocket and explored the possibility of interplanetary travels by rockets. In one of his works he set forth his theory of motion of rockets, established the possibilities of space travel by means of rockets, and the fundamental flight formulae he came up with. In mid 1920s his works on rocket engineering and space flight won international recognition. 

1945: Author Arthur C Clarke proposes a geosynchronous satellite at a particular height hovering over the same spot on earth because it revolves at the same speed as earth’s rotation. The geo-stationary orbit has been named after him as Clarke Orbit. 

1957: Soviet Union launches the first artificial satellite, Sputnik I, on 4 October. It was about 58 centimeters in diameter and weighed about 84 kilograms. The satellite circled the earth once every 96 minutes and transmitted radio signals to the earth. The orbit of Sputnik I helped scientists to learn about the density of the atmosphere. Although Sputnik I only proved Newton’s idea, it was responsible for the beginning the space race. The second Sputnik series satellite, Sputnik 2, was launched on 3 November. The unique thing about this satellite was that it was carrying, Laika, the dog into space.

1958: The launches resulted in a competition between the US and Soviet Union for the launch of satellites. The US launched its first satellite–Explorer I–on 31 January. Explorer 1 and Explorer 3 failed in their missions. James Van Allen suspected the cause of the failure of the Explorer series satellites to be high level of radiation. He designed a better radiation counter for Explorer 4 and launched it on 2 July, which resulted in the discovery of the Van Allen radiation belt that surrounds the earth.

1960: Echo, the first passive communications satellite is launched on 12 August as a result of efforts by John Robinson Pierce, who believed that the future of communications was dependent on satellite. TIROS 1 (Television Infrared Observation Satellite), launched on 1 April, 1960, was the first series of meteorological satellites to carry television cameras to photograph the Earth’s cloud cover and demonstrate the value of using spacecraft for meteorological forecasting. The first navigational satellite was Transi 1B. 

1961: Yuri Gagarin of the erstwhile Soviet Union makes the first orbital flight in a spacecraft in Vostok 1 on 12 April, making a single orbit in a flight of one hour 48 minutes. 

1962: On 20 February, John Glenn Jr completes the first orbital flight by an American, the Mercury 6 mission of the Friendship 7, in three orbits. Telstar, the first active communications satellite is launched on 10 July. It relays the first transatlantic (Europe and America) TV pictures and phone calls. Telstar was an active satellite with a microwave receiver and transmitter. Each transmission lasted for only 20 minutes as the ground stations in England and Maine could see the satellite simultaneously only for that period of time. Telstar was capable of handling 600 telephone channels or one television channel. 

1963: Valentina Tereshkova, the first woman cosmonaut, is launched on 48-orbit Soviet space mission Vostok 6 on 16 June, a dual launch with Vostok 5. Telstar 2 is also launched which establishes the first direct link between Japan and Europe. 

1964: The International Telecommunications Satellite Organization (Intelsat) is set up by the US and eleven other countries to develop a global commercial telecommunications satellite system. Soviet cosmonauts, Vladimir Komarov, Konstantin Feotistov, and Boris Yegorov, the first multiperson crew in space, are launched on the 16-orbit Voskhod 1 mission on 12 October. 

1965: Early Bird (Intelsat 1) is the first commercial telecommunications satellite placed on a geostationary orbit by Intelsat; it could relay 240 telephone conversations simultaneously. The Soviet Union launches its first domestic communications satellite–Molniya. 

1970: The US Apollo 13 mission starts off on 11 April. The first Chinese and Japanese artificial satellites are also launched.

1973: Scientific Atlanta introduces the first mobile earth station for communications satellite. On 6 March, the US launches Pioneer 11, the first space probe to reach the vicinity of Saturn.

On 25 May, the first US space station, Skylab 2, is launched. On 3 November, the US launches Mariner 10, the first space probe to observe Venus and Mercury. 

1979: The first of the European Space Agency’s Ariane rockets successfully lifts off on 24 December from the Guiana Space Centre in Kourou, French Guiana. The rocket is designed to launch satellites into orbit for various customers, including the space agency and commercial users. 

1987: Telephones become available on Japanese airliners; calls are relayed by satellite.



Soviet cosmonaut Yuri V Romanenko returns to earth from the Mir space station after 326 days in space. 

1998: In May 1998, Iridium, a constellation of 66 satellites, completes the successful launch of all its satellites in space. In November 1998 Iridium launches its commercial service globally to provide voice communication to people irrespective of time and place. Based on the Low Earth Orbit (LEO), the satellite is at an altitude of 780 kilometers. For the first time the switching was within the satellite. The Iridium system tends to employ a combination

of FDMA and TDMA multiplexing techniques.

1999: In October 1999, Globalstar, a constellation of 48 satellites launches its service in ITU ’99 and becomes the second GMPCS operator to start the services after Iridium in countries like the US, Canada, Brazil, Argentina, China, Korea, South Africa, and parts of Europe.

Situated at a height of 1,400 kilometers, Globalstar is presently providing voice, and will provide data and fax capabilities starting next year. 

2001: Satellite-based service for around 8 cents to 35 cents–almost equivalent to present day cellular call charge for voice calls and data transmission, also supporting end-user equipment like data only terminals, personal digital assistants, and paging or polling terminals. In the end of 2001 we can see Ellipso offering these services through its constellation of 17 LEO satellites operating in a unique orbital architecture having sun synchronous orbits that allow the satellite to spend more time during daylight hours over high population areas. Unlike typical circular orbits, Ellipso’s inclined and equatorial orbits are believed to put more communications capacity on the ground where and when it is needed the most. 

2003: Teledesic is the first satellite system designed and constructed to operate as a broadband satellite network. Its interconnected satellites will provide interactive broadband service with end-to-end guaranteed quality of services. It is focussed to provide global broadband networking and mission-critical applications, ranging from ERP to carrier grade voice to collaborative computing. Teledesic will also provide bandwidth on demand at a cost dependent of

location.