Geostationary orbit

A geostationary orbit referred to as a geosynchronous equatorial orbit, is a circular geosynchronous orbit 35,786 kilometres above Earth's equator and following the direction of Earth's rotation. An object in such an orbit has an orbital period equal to the Earth's rotational period, one sidereal day, so to ground observers it appears motionless, in a fixed position in the sky; the concept of a geostationary orbit was popularised by Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, the first satellite to be placed in this kind of orbit was launched in 1963. Communications satellites are placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located. Weather satellites are placed in this orbit for real time monitoring and data collection, navigation satellites to provide a known calibration point and enhance GPS accuracy. Geostationary satellites are launched via a temporary orbit, placed in a slot above a particular point on the Earth's surface.

The orbit requires some stationkeeping to keep its position, modern retired satellites are placed in a higher graveyard orbit to avoid collisions. The first appearance of a geostationary orbit in popular literature was in October 1942, in the first Venus Equilateral story by George O. Smith, but Smith did not go into details. British science fiction author Arthur C. Clarke popularised and expanded the concept in a 1945 paper entitled Extra-Terrestrial Relays – Can Rocket Stations Give Worldwide Radio Coverage?, published in Wireless World magazine. Clarke acknowledged the connection in his introduction to The Complete Venus Equilateral; the orbit, which Clarke first described as useful for broadcast and relay communications satellites, is sometimes called the Clarke Orbit. The collection of artificial satellites in this orbit is known as the Clarke Belt. In technical terminology the orbit is referred to as either a geostationary or geosynchronous equatorial orbit, with the terms used somewhat interchangeably.

The first geostationary satellite was designed by Harold Rosen while he was working at Hughes Aircraft in 1959. Inspired by Sputnik 1, he wanted to use a geostationary satellite to globalise communications. Telecommunications between the US and Europe was possible between just 136 people at a time, reliant on high frequency radios and an undersea cable. Conventional wisdom at the time was that it would require too much rocket power to place a satellite in a geostationary orbit and it would not survive long enough to justify the expense, so early efforts were put towards constellations of satellites in low or medium Earth orbit; the first of these were the passive Echo balloon satellites in 1960, followed by Telstar 1 in 1962. Although these projects had difficulties with signal strength and tracking, that could be solved through geostationary satellites, the concept was seen as impractical, so Hughes withheld funds and support. By 1961, Rosen and his team had produced a cylindrical prototype with a diameter of 76 centimetres, height of 38 centimetres, weighing 11.3 kilograms and small enough to be placed into orbit.

It was spin stabilised with a dipole antenna producing a pancake shaped waveform. In August 1961, they were contracted to begin building the real satellite, they lost Syncom 1 to electronics failure, but Syncom 2 was placed into a geosynchronous orbit in 1963. Although its inclined orbit still required moving antennas, it was able to relay TV transmissions, allowed for US President John F. Kennedy to phone Nigerian prime minister Abubakar Tafawa Balewa from a ship on August 23, 1963; the first satellite placed in a geostationary orbit was Syncom 3, launched by a Delta D rocket in 1963. With its increased bandwidth, this satellite was able to transmit live coverage of the Summer Olympics from Japan to America. Geostationary orbits have been in common use since, in particular for satellite television. Today there are hundreds of geostationary satellites providing remote communications. Although most populated land locations on the planet now have terrestrial communications facilities, with telephone access covering 96% of the population and internet access 90%, some rural and remote areas in developed countries are still reliant on satellite communications.

Most commercial communications satellites, broadcast satellites and SBAS satellites operate in geostationary orbits. Geostationary communication satellites are useful because they are visible from a large area of the earth's surface, extending 81° away in both latitude and longitude, they appear stationary in the sky, which eliminates the need for ground stations to have movable antennas. This means that Earth based observers can erect small and stationary antennas that are always directed at the desired satellite. However, latency becomes significant as it takes about 240ms for a signal to pass from a ground based transmitter on the equator to the satellite and back again; this delay presents problems for latency-sensitive applications such as voice communication, so geostationary communication satellites are used for unidirectional entertainment and applications where low latency alternatives are not available. Geostationary satellites are directly overhead at the equator and appear lower in the sky to an observer nearer the poles.

As the observer's latitude increases, communication becomes more difficult due to factors such as atmospheric refraction, Earth's thermal emission, line-of-sight obstructions, signal reflections from the ground or nearby structures. At latitudes above about 81°, geostationary sa


Contigliano is a comune in the Province of Rieti in the Italian region Latium, located about 60 kilometres northeast of Rome and about 8 kilometres west of Rieti. Contigliano borders the following municipalities: Casperia, Colli sul Velino, Greccio, Rieti; the most important church in town is the church of San Michele Arcangelo. Among the other churches, is the church of Sant'Antonio, San Lorenzo, the Abbey of San Pastore. Contigliano has a station on the Terni -- Sulmona railway, with trains to Rieti and L'Aquila. Official website This link includes genealogical information about some of the families of Contigliano. Https://

Aseff Ahmad Daula

Sardar Asif Ahmad Ali Daula is a Pakistani politician who served as the 18th Foreign Minister of Pakistan from 1993 to 1996. He is a senior member of Pakistan Peoples Party. On 25 December 2011, he joined PTI but resigned when party awarded Khurshid Kasuri National Assembly ticket instead of him, he was elected to the National Assembly of Pakistan from Kasur in 1994 and again in 2008 by an impressive margin of ten thousand votes. He has served as the Minister for Education and Federal Minister of Information Technology and Telecommunication between 2008 and 2010, he rejoined Pakistan Tehreek e Insaf on 10 November 2017 during a press conference with Imran Khan in Lahore. He studied at Lawrence College in Ghora Gali, he earned a B. A. degree from Government College University, a B. A degree from St John's College, Oxford. Sardar Aseff Ahmad Ali was a senior member of the Pakistan Peoples Party, he was the foreign minister of Pakistan in the cabinet of Benazir Bhutto during her second tenure as Prime Minister.

He resigned from Pakistan Peoples Party and Join Party of Imran Khan former crickter Pakistan Tehreek-e-Insaf. He opposed Pervez Musharraf's firing of Pakistan's judiciary, he was a close associate of Benazir Bhutto and was the head of foreign policy of Pakistan Peoples Party during the 90's. Sardar Aseff Ahmed Ali belongs to a principal landholding Arain/ Daula family of the Punjab region whose role in politics, in this region precedes the British rule in India; the family has a reputation of repelling authority and was instrumental in fighting against the Sikhs and the British. His uncle Sardar Muhammad Hussain remained a member of parliament pre and post partition and pioneered the advent of Pakistan Muslim League in central Punjab region, his father Sardar Ahmed Ali who remained a member of parliament throughout his career, Sardar Muhammad Hussain led regional movements against the Unionist Party led by wealthy Zamindars and patronized by the British. Sardar Aseff served as the Minister for Economic Affairs during the 1991–1993 Nawaz Sharif government, but resigned from the cabinet after developing differences with the Prime Minister.

His resignation along with those of other members of parliament led to overthrow of the first Nawaz Sharif government. While serving as the Economic Affairs Minister, Sardar Aseff led numerous delegations of Pakistani civil society members and organisations to Russia and cultivated business and diplomatic relationships with various disintegrated states of the former Soviet Union.} He was awarded honorary citizenship of Kyrgyzstan. As Foreign Minister of Pakistan, he was unanimously elected chairman of the Organisation of the Islamic Conference. In 2003, he held a painting exhibition at Lahore, where he displayed some of his hand-drawn sketches and paintings, attended by then-Prime Minister Zafarullah Khan Jamali. In the held general elections, he was returned to the National Assembly for the fifth time after defeating his archrival, the outgoing foreign minister Khurshid Mahmud Kasuri. DAWN Hot Seat: Sardar Aseff Ahmad Ali