The Soyuz-FG launch vehicle is an improved version of the Soyuz-U from the R-7 family of rockets and constructed by TsSKB-Progress in Samara, Russia. It made its maiden flight on 20 May 2001, carrying a Progress cargo spacecraft to the International Space Station. Since 30 October 2002, Soyuz-FG has been the only vehicle used by the Russian Federal Space Agency to launch Soyuz-TMA and Soyuz-MS manned spacecraft to the ISS; the Soyuz-FG performed 64 successful launches until its first failure on 11 October 2018 with the Soyuz MS-10 mission. Soyuz-FG can optionally fly with a Fregat upper stage and produced by Lavochkin Association in Khimki. Launches of the Soyuz-FG/Fregat configuration are marketed by a European-Russian company called Starsem, its maiden flight occurred on 2 June 2003. As of December 2014, there have been 10 launches of Soyuz-FG/Fregat with commercial payloads; the analog control system limits the capabilities of this launcher, it will be replaced by Soyuz-2 in 2019. Soyuz-FG is launched from the Baikonur Cosmodrome in Kazakhstan, from Gagarin's Start for manned missions, from LC-31/6 for satellite launches with the Fregat variant.
On 1 November 2018, Russian scientists released a video recording of the Soyuz MS-10 manned spaceflight involving a Soyuz-FG rocket after launch on 11 October 2018 that, due to a faulty sensor, resulted in the destruction of the rocket. The crew, NASA astronaut Nick Hague and Russian cosmonaut Aleksey Ovchinin. Escaped safely and successfully. Soyuz Soyuz programme Russian Federal Space Agency Starsem McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 28 March 2013. McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 28 March 2013. Russian Federal Space Agency about Soyuz-FG LV's manufacturer TsSKB-Progress about Soyuz-FG
An atomic clock is a clock device that uses an electron transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, in global navigation satellite systems such as GPS; the principle of operation of an atomic clock is based on atomic physics. Early atomic clocks were based on masers at room temperature. Since 2004, more accurate atomic clocks first cool the atoms to near absolute zero temperature by slowing them with lasers and probing them in atomic fountains in a microwave-filled cavity. An example of this is the NIST-F1 atomic clock, one of the national primary time and frequency standards of the United States; the accuracy of an atomic clock depends on two factors. The first factor is temperature of the sample atoms—colder atoms move much more allowing longer probe times.
The second factor is the frequency and intrinsic width of the electronic transition. Higher frequencies and narrow lines increase the precision. National standards agencies in many countries maintain a network of atomic clocks which are intercompared and kept synchronized to an accuracy of 10−9 seconds per day; these clocks collectively define the International Atomic Time. For civil time, another time scale is disseminated, Coordinated Universal Time. UTC is derived from TAI, but has added leap seconds from UT1, to account for variations in the rotation of the Earth with respect to the solar time; the idea of using atomic transitions to measure time was suggested by Lord Kelvin in 1879. Magnetic resonance, developed in the 1930s by Isidor Rabi, became the practical method for doing this. In 1945, Rabi first publicly suggested that atomic beam magnetic resonance might be used as the basis of a clock; the first atomic clock was an ammonia absorption line device at 23870.1 MHz built in 1949 at the U.
S. National Bureau of Standards, it served to demonstrate the concept. The first accurate atomic clock, a caesium standard based on a certain transition of the caesium-133 atom, was built by Louis Essen and Jack Parry in 1955 at the National Physical Laboratory in the UK. Calibration of the caesium standard atomic clock was carried out by the use of the astronomical time scale ephemeris time. In 1967, this led the scientific community to redefine the Second in terms of a specific atomic frequency. Equality of the ET second with the SI second has been verified to within 1 part in 1010; the SI second thus inherits the effect of decisions by the original designers of the ephemeris time scale, determining the length of the ET second. Since the beginning of development in the 1950s, atomic clocks have been based on the hyperfine transitions in hydrogen-1, caesium-133, rubidium-87; the first commercial atomic clock was the Atomichron, manufactured by the National Company. More than 50 were sold between 1956 and 1960.
This bulky and expensive instrument was subsequently replaced by much smaller rack-mountable devices, such as the Hewlett-Packard model 5060 caesium frequency standard, released in 1964. In the late 1990s four factors contributed to major advances in clocks: Laser cooling and trapping of atoms So-called high-finesse Fabry–Pérot cavities for narrow laser line widths Precision laser spectroscopy Convenient counting of optical frequencies using optical combs. In August 2004, NIST scientists demonstrated a chip-scale atomic clock. According to the researchers, the clock was believed to be one-hundredth the size of any other, it requires no more than 125 mW. This technology became available commercially in 2011. Ion trap. In April 2015, NASA announced that it planned to deploy a Deep Space Atomic Clock, a miniaturized, ultra-precise mercury-ion atomic clock, into outer space. NASA said. Since 1967, the International System of Units has defined the second as the duration of 9192631770 cycles of radiation corresponding to the transition between two energy levels of the ground state of the caesium-133 atom.
In 1997, the International Committee for Weights and Measures added that the preceding definition refers to a caesium atom at rest at a temperature of absolute zero. This definition makes the caesium oscillator the primary standard for time and frequency measurements, called the caesium standard; the definitions of other physical units, e.g. the volt and the metre, rely on the definition of the second. The actual time-reference of an atomic clock consists of an electronic oscillator operating at microwave frequency; the oscillator is arranged so that its frequency-determining components include an element that can be controlled by a feedback signal. The feedback signal keeps the oscillator tuned in resonance with the frequency of the electronic transition of caesium or rubidium; the core of the atomic clock is a tunable microwave cavity containing a gas. In a hydrogen maser clock the gas emits microwaves on a hyperfine transition, the field in the cavity oscillates, the cavity is tuned for maximum microwave amplitude.
Alternatively, in a caesium or rubidium clock, the beam or gas absorbs microwaves and the cavity contains an electronic amplifier to make it oscillate. For both types the atoms in the gas
A natural satellite or moon is, in the most common usage, an astronomical body that orbits a planet or minor planet. In the Solar System there are six planetary satellite systems containing 185 known natural satellites. Four IAU-listed dwarf planets are known to have natural satellites: Pluto, Haumea and Eris; as of September 2018, there are 334 other minor planets known to have moons. The Earth–Moon system is unique in that the ratio of the mass of the Moon to the mass of Earth is much greater than that of any other natural-satellite–planet ratio in the Solar System. At 3,474 km across, the Moon is 0.27 times the diameter of Earth. The first known natural satellite was the Moon, but it was considered a "planet" until Copernicus' introduction of De revolutionibus orbium coelestium in 1543; until the discovery of the Galilean satellites in 1610, there was no opportunity for referring to such objects as a class. Galileo chose to refer to his discoveries as Planetæ, but discoverers chose other terms to distinguish them from the objects they orbited.
The first to use of the term satellite to describe orbiting bodies was the German astronomer Johannes Kepler in his pamphlet Narratio de Observatis a se quatuor Iouis satellitibus erronibus in 1610. He derived the term from the Latin word satelles, meaning "guard", "attendant", or "companion", because the satellites accompanied their primary planet in their journey through the heavens; the term satellite thus became the normal one for referring to an object orbiting a planet, as it avoided the ambiguity of "moon". In 1957, the launching of the artificial object Sputnik created a need for new terminology. Sputnik was created by Soviet Union, it was the first satellite ever; the terms man-made satellite and artificial moon were quickly abandoned in favor of the simpler satellite, as a consequence, the term has become linked with artificial objects flown in space – including, sometimes those not in orbit around a planet. Because of this shift in meaning, the term moon, which had continued to be used in a generic sense in works of popular science and in fiction, has regained respectability and is now used interchangeably with natural satellite in scientific articles.
When it is necessary to avoid both the ambiguity of confusion with Earth's natural satellite the Moon and the natural satellites of the other planets on the one hand, artificial satellites on the other, the term natural satellite is used. To further avoid ambiguity, the convention is to capitalize the word Moon when referring to Earth's natural satellite, but not when referring to other natural satellites. Many authors define "satellite" or "natural satellite" as orbiting some planet or minor planet, synonymous with "moon" – by such a definition all natural satellites are moons, but Earth and other planets are not satellites. A few recent authors define "moon" as "a satellite of a planet or minor planet", "planet" as "a satellite of a star" – such authors consider Earth as a "natural satellite of the sun". There is no established lower limit on what is considered a "moon"; every natural celestial body with an identified orbit around a planet of the Solar System, some as small as a kilometer across, has been considered a moon, though objects a tenth that size within Saturn's rings, which have not been directly observed, have been called moonlets.
Small asteroid moons, such as Dactyl, have been called moonlets. The upper limit is vague. Two orbiting bodies are sometimes described as a double planet rather than satellite. Asteroids such as 90 Antiope are considered double asteroids, but they have not forced a clear definition of what constitutes a moon; some authors consider the Pluto–Charon system to be a double planet. The most common dividing line on what is considered a moon rests upon whether the barycentre is below the surface of the larger body, though this is somewhat arbitrary, because it depends on distance as well as relative mass; the natural satellites orbiting close to the planet on prograde, uninclined circular orbits are thought to have been formed out of the same collapsing region of the protoplanetary disk that created its primary. In contrast, irregular satellites are thought to be captured asteroids further fragmented by collisions. Most of the major natural satellites of the Solar System have regular orbits, while most of the small natural satellites have irregular orbits.
The Moon and Charon are exceptions among large bodies in that they are thought to have originated by the collision of two large proto-planetary objects. The material that would have been placed in orbit around the central body is predicted to have reaccreted to form one or more orbiting natural satellites; as opposed to planetary-sized bodies, asteroid moons are thought to form by this process. Triton is another exception; the capture of an asteroid from a heliocentric orbit is not always permanent. According to simulations, temporary satellites should be a common phenomenon; the only observed example is 2006 RH120, a temporary satellite of Earth for nine months in 2006 and 2007. Most regular moons (natural satellites following close and prograde orbits with small orb
International Telecommunication Union
The International Telecommunication Union the International Telegraph Union, is a specialized agency of the United Nations, responsible for issues that concern information and communication technologies. It is the oldest among all the 15 specialised agencies of UN; the ITU coordinates the shared global use of the radio spectrum, promotes international cooperation in assigning satellite orbits, works to improve telecommunication infrastructure in the developing world, assists in the development and coordination of worldwide technical standards. The ITU is active in areas including broadband Internet, latest-generation wireless technologies and maritime navigation, radio astronomy, satellite-based meteorology, convergence in fixed-mobile phone, Internet access, voice, TV broadcasting, next-generation networks; the agency organizes worldwide and regional exhibitions and forums, such as ITU Telecom World, bringing together representatives of government and the telecommunications and ICT industry to exchange ideas and technology.
ITU, based in Geneva, Switzerland, is a member of the United Nations Development Group, has 12 regional and area offices in the world. ITU has been an intergovernmental public–private partnership organization since its inception, its membership includes 193 Member States and around 800 public and private sector companies, academic institutions as well as international and regional telecommunication entities, known as Sector Members and Associates, which undertake most of the work of each Sector. ITU was formed in Paris, at the International Telegraph Convention; the International Radiotelegraph Union was unofficially established at first International Radiotelegraph Convention in 1906. Both were merged into the International Telecommunication Union in 1932. ITU became a United Nations specialized agency in 1947; the ITU comprises three sectors, each managing a different aspect of the matters handled by the Union, as well as ITU Telecom. The sectors were created during the restructuring of ITU at its 1992 Plenipotentiary Conference.
Radio communication Established in 1927 as the International Radio Consultative Committee or CCIR, this sector manages the international radio-frequency spectrum and satellite orbit resources. In 1992, the CCIR became the ITU-R. Standardisation Standardisation was the original purpose of ITU since its inception. Established in 1956 as the International Telephone and Telegraph Consultative Committee or CCITT, this sector standardizes global telecommunications. In 1993, the CCITT became the ITU-T. Development Established in 1992, this sector helps spread equitable and affordable access to information and communication technologies. ITU Telecom ITU Telecom organizes major events for the world's ICT community. A permanent General Secretariat, headed by the Secretary General, manages the day-to-day work of the Union and its sectors; the basic texts of the ITU are adopted by the ITU Plenipotentiary Conference. The founding document of the ITU was the 1865 International Telegraph Convention, which has since been amended several times and is now entitled the "Constitution and Convention of the International Telecommunication Union".
In addition to the Constitution and Convention, the consolidated basic texts include the Optional Protocol on the settlement of disputes, the Decisions and Recommendations in force, as well as the General Rules of Conferences and Meetings of the Union. The ITU is headed by a Secretary-General, a Deputy Secretary General and the three directors of the Bureaux, who are elected to a four-year terms by the member states at the ITU Plenipotentiary Conference. On 23 October 2014 Houlin Zhao was elected 19th Secretary-General of the ITU at the Plenipotentiary Conference in Busan, Republic of Korea, his four-year mandate started on 1 January 2015, he was formally inaugurated on 15 January 2015. Houlin Zhao was reelected at the 2018 Plenipotentiary Conference in Dubai. Membership of ITU is open to only Member States of the United Nations, which may join the Union as Member States, as well as to private organizations like carriers, equipment manufacturers, funding bodies and development organizations and international and regional telecommunication organizations, which may join ITU as non-voting Sector Members.
There are 193 Member States of the ITU, including all UN member states except the Republic of Palau, plus the Vatican City. The most recent member state to join the ITU is South Sudan, which became a member on 14 July 2011; the Republic of China was blocked from membership by the People's Republic of China, but received a country code, being listed as "Taiwan, China". Palestine was admitted as an observer in 2010. Six Regional Offices and seven Area Offices guarantee a regional presence of ITU: Regional Office for CSI Africa Regional Office in Addis Ababa, with Area Offices in Dakar and Yaoundé Arab States Regional Office in Cairo Asia-Pacific Regional Office in Bangkok, with Area Office in Jakarta America Regional Office in Brasilia, with Area Offices in Bridgetown and Tegucigalpa; the sixth is a Coordination office for Europe Region Europe at ITU Headquarters. Other Regional organizations, connected to ITU, are: Asia-Pacific Telecommunity Arab Spectrum Management Group African Telecommunications Union European Conference of Posta
Hampshire is a county on the southern coast of England. The county town is the city of Winchester, its two largest cities and Portsmouth, are administered separately as unitary authorities. First settled about 14,000 years ago, Hampshire's history dates to Roman Britain, when its chief town was Winchester; when the Romans left Britain, the area was infiltrated by tribes from Scandinavia and mainland Europe, principally in the river valleys. The county was recorded in the 11th century Domesday Book, divided into 44 hundreds. From the 12th century, the ports grew in importance, fuelled by trade with the continent and cloth manufacture in the county, the fishing industry, a shipbuilding industry was established. By the 16th century, the population of Southampton had outstripped that of Winchester. By the mid-19th century, with the county's population at 219,210 in more than 86,000 dwellings, agriculture was the principal industry and 10 per cent of the county was still forest. Hampshire played a crucial military role in both World Wars.
The Isle of Wight left the county to form its own in 1974. The county's geography is varied, with upland to 286 metres and south-flowing rivers. There are areas of downland and marsh, two national parks: the New Forest, part of the South Downs, which together cover 45 per cent of Hampshire. Hampshire is one of the most affluent counties in the country, with an unemployment rate lower than the national average, its economy derived from major companies, maritime and tourism. Tourist attractions include the national parks and the Southampton Boat Show; the county is known as the home of writers Jane Austen and Charles Dickens, the childhood home of Florence Nightingale and the birthplace of engineer Isambard Kingdom Brunel. Hampshire takes its name from the settlement, now the city of Southampton. Southampton was known in Old English as Hamtun meaning "village-town", so its surrounding area or scīr became known as Hamtunscīr; the old name was recorded in the Domesday book as Hantescire, from this spelling, the modern abbreviation "Hants" derives.
From 1889 until 1959, the administrative county was named the County of Southampton and has been known as Southamptonshire. Hampshire was the departure point of some of those who left England to settle on the east coast of North America during the 17th century, giving its name in particular to the state of New Hampshire; the towns of Portsmouth, New Hampshire and Portsmouth, Virginia take their names from Portsmouth in Hampshire. The region is believed to have been continuously occupied since the end of the last Ice Age about 12,000 BCE. At this time, Britain was still attached to the European continent and was predominantly covered with deciduous woodland; the first inhabitants were Mesolithic hunter-gatherers. The majority of the population would have been concentrated around the river valleys. Over several thousand years, the climate became progressively warmer, sea levels rose. Notable sites from this period include Bouldnor Cliff. Agriculture had arrived in southern Britain by 4000 BCE, with it a neolithic culture.
Some deforestation took place at that time, although during the Bronze Age, beginning in 2200 BCE, this became more widespread and systematic. Hampshire has few monuments to show from these early periods, although nearby Stonehenge was built in several phases at some time between 3100 and 2200 BCE. In the late Bronze Age, fortified hilltop settlements known as hillforts began to appear in large numbers in many parts of Britain including Hampshire, these became more and more important in the early and middle Iron Age. By this period, the people of Britain predominantly spoke a Celtic language, their culture shared much in common with the Celts described by classical writers. Hillforts declined in importance in the second half of the second century BCE, with many being abandoned. Around this period, the first recorded invasion of Britain took place, as southern Britain was conquered by warrior-elites from Belgic tribes of northeastern Gaul - whether these two events are linked to the decline of hillforts is unknown.
By the Roman conquest, the oppidum at Venta Belgarum, modern-day Winchester, was the de facto regional administrative centre. Julius Caesar invaded southeastern England in 55 and again in 54 BCE, but he never reached Hampshire. Notable sites from this period include Hengistbury Head, a major port; the Romans invaded Britain again in 43 CE, Hampshire was incorporated into the Roman province of Britannia quickly. It is believed their political leaders allowed themselves to be incorporated peacefully. Venta became the capital of the administrative polity of the Belgae, which included most of Hampshire and Wiltshire and reached as far as Bath. Whether the people of Hampshire played any role in Boudicca's rebellion of 60-61 CE is not recorded, but evidence of burning is seen in Winchester dated to around this period. For most of the next three centuries, southern Britain enjoyed relative peace; the part of th
A geostationary orbit referred to as a geosynchronous equatorial orbit, is a circular geosynchronous orbit 35,786 km above Earth's equator and following the direction of Earth's rotation. An object in such an orbit appears motionless, at a fixed position in the sky, to ground observers. Communications satellites and weather satellites are placed in geostationary orbits, so that the satellite antennae that communicate with them do not have to rotate to track them, but can be pointed permanently at the position in the sky where the satellites are located. Using this characteristic, ocean-color monitoring satellites with visible and near-infrared light sensors can be operated in geostationary orbit in order to monitor sensitive changes of ocean environments. A geostationary orbit is a particular type of geosynchronous orbit, which has an orbital period equal to Earth's rotational period, or one sidereal day. Thus, the distinction is that, while an object in geosynchronous orbit returns to the same point in the sky at the same time each day, an object in geostationary orbit never leaves that position.
Geosynchronous orbits move around relative to a point on Earth's surface because, while geostationary orbits have an inclination of 0° with respect to the Equator, geosynchronous orbits have varying inclinations and eccentricities. 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 disseminated the idea with more details on how it would work, 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 Clarke Belt is the part of space about 35,786 km above sea level, in the plane of the equator, where near-geostationary orbits may be implemented.
The Clarke Orbit is about 265,000 km in circumference. Most commercial communications satellites, broadcast satellites and SBAS satellites operate in geostationary orbits. A geostationary transfer orbit is used to move a satellite from low Earth orbit into a geostationary orbit; the first satellite placed into a geostationary orbit was the Syncom-3, launched by a Delta D rocket in 1964. A worldwide network of operational geostationary meteorological satellites is used to provide visible and infrared images of Earth's surface and atmosphere; these satellite systems include: the United States GOES Meteosat, launched by the European Space Agency and operated by the European Weather Satellite Organization, EUMETSAT the Repulic of Korea COMS, GK-2A the Japanese Himawari Chinese Fengyun India's INSAT series A statite, a hypothetical satellite that uses a solar sail to modify its orbit, could theoretically hold itself in a geostationary "orbit" with different altitude and/or inclination from the "traditional" equatorial geostationary orbit.
Satellites in geostationary orbits are far enough away from Earth that communication latency becomes significant — about a quarter of a second for a trip from one ground-based transmitter to the satellite and back to another ground-based transmitter. For example, for ground stations at latitudes of φ = ±45° on the same meridian as the satellite, the time taken for a signal to pass from Earth to the satellite and back again can be computed using the cosine rule, given the geostationary orbital radius r, the Earth's radius R and the speed of light c, as Δ t = 2 c R 2 + r 2 − 2 R r cos φ ≈ 253 ms; this delay presents problems for latency-sensitive applications such as voice communication. 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 satellites are below the horizon and cannot be seen at all. Because of this, some Russian communication satellites have used elliptical Molniya and Tundra orbits, which have excellent visibility at high latitudes. Satellites in geostationary orbit must all occupy a single ring above the equator; the requirement to space these satellites apart to avoid harmful radio-frequency interference during operations means that there are a limited number of orbital "slots" available, thus only a limited number of satellites can be operated in geostationary orbit. This has led to conflict between different countries wishing access to the same orbital slots and radio frequencies; these disputes are addressed through the International Telecommunication Union's allocation mechanism. In the 1976 Bogotá Declaration, eight countries located on the Earth's equator claimed sovereignty ov
Septentrio is a designer and manufacturer of high-end multi-frequency GNSS receivers. Its main target is to provide GNSS receiver boards for further system integration by Original Equipment Manufacturers. Septentrio's core technology is used in various professional fields such as land and airborne surveying, machine control, precise agriculture, marine applications, timing etc. Septentrio Satellite Navigation N. V. was incorporated by Peter Grognard, Founder,in Leuven, Belgium, in January 2000 to commercialize the Satellite Navigation know-how developed at the Interuniversity Micro Electronics Center, the largest independent microelectronics R&D lab in Belgium. In 2007 Septentrio received the Trends Gazelle award for the fastest rate of growth among Belgian start-up companies. Septentrio's headquarters are located in Belgium. Operations for North and Latin American are based in Torrance and the Asian-Pacific operations are based in Hong Kong. Septentrio has an international team of experts, who cover all the fields of Satellite Navigation technology.
The company designs its own chipsets, hardware and algorithms. Being a provider of high-end receivers for professional use, Septentrio prioritizes the reliability and precision of measurements as well as high degree of flexibility and user control. Septentrio’s products make use of APME, the company’s original multipath-mitigation technology, on-the-fly ambiguity fixing schemes based on the LAMBDA method, advanced user-controlled RAIM algorithms. Septentrio is known to first introduce single-board attitude determination systems based on the multi-antenna version of its GPS receivers. Septentrio’s receivers were used to track experimental Galileo signals transmitted by the GIOVE-A satellite and were the first to track the signals of the first experimental satellite of the future Chinese Compass navigation system. In the line of user products the company keeps its focus on multi-system receivers that make use of all the navigation signals available in the sky. Official website APME multipath mitigation technique Attitude determination Multi-frequency combinations of observables Inside GNSS Tracking Compass signals Inside GNSS Trends-Gazelle award April 2007 Septentrio's receiver at the MIZU geodetic station records the earthquakes Septentrio reports the tracking of the GLONASS CDMA signal Inside GNSS, see GLONASS-Khttps://www.gpsworld.com/2013-leadership-awards-the-honorees-speak/