Biology.

Specific terms and specialized language are used to describe equine anatomy, different life stages, and colors and breeds.

Lifespan and life stages.

Depending on breed, management and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and, occasionally, beyond. The oldest verifiable record was "Old Billy", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had been listed in "Guinness World Records" as the world's oldest living pony, died in 2007 at age 56.  Regardless

Size and measurement.

The height of horses is measured at the highest point of the withers, where the neck meets the back. This point is used because it is a stable point of the anatomy, unlike the head or neck, which move up and down in relation to the body of the horse.  In English-speaking countries, the height of horses is often stated in units of hands and inches: one hand is equal to. The height is expressed as the number of full hands, followed by a point, then the number of additional inches, and ending with the

Ponies.

Ponies are taxonomically the same animals as horses. The distinction between a horse and pony is commonly drawn on the basis of height, especially for competition purposes. However, height alone is not dispositive; the difference between horses and ponies may also include aspects of phenotype, including conformation and temperament.  The traditional standard for height of a horse or a pony at maturity is. An animal 14.2 h or over is usually considered to be a horse and one less than 14.2 h a pony, but there are many exceptions to the traditional standard. In Australia, ponies are considered to be those under. For competition in the Western division of the United States Equestrian Federation, the cutoff is. The International Federation for Equestrian Sports, the world governing body for horse sport, uses metric

Genetics.

Horses have 64 chromosomes. The horse genome was sequenced in 2007. It contains 2.7 billion DNA

Colors and markings.

Horses exhibit a diverse array of coat colors and distinctive markings, described by a specialized vocabulary. Often, a horse is classified first by its coat color, before breed or sex. Horses of the same color may be distinguished from one another by white markings, which, along with various spotting patterns, are inherited separately from coat color.  Many genes that create horse coat colors and patterns have been identified. Current genetic tests can identify at least 13 different alleles influencing coat color, and research continues to discover new genes linked to specific traits. The basic coat colors of chestnut and black are determined by the gene controlled by the Melanocortin 1 receptor, also known as the "extension gene"

Reproduction and development.

Gestation lasts approximately 340 days, with an average range 320–370 days, and usually results in one foal; twins are rare. Horses are a precocial species, and foals are capable of standing and running within a short time following birth. Foals are usually born in the spring. The estrous cycle of a mare occurs roughly every 19–22 days and occurs from early spring into autumn. Most mares enter an "anestrus" period during the winter and thus do not cycle in this period. Foals are generally weaned from their mothers between four and six months of age.  Horses, particularly colts, sometimes are physically capable of reproduction at about 18 months, but domesticated horses are rarely allowed to breed before the age of

Anatomy.

Skeletal system.

The horse skeleton averages 205 bones. A significant difference between the horse skeleton and that of a human is the lack of a collarbone—the horse's forelimbs are attached to the spinal column by a powerful set of muscles, tendons, and ligaments that attach the shoulder blade to the torso. The horse's four legs and hooves are also unique structures. Their leg bones are proportioned differently from those of a human. For example, the body part that is called a

Hooves.

The critical importance of the feet and legs is summed up by the traditional adage, "no foot, no horse". The horse hoof begins with the distal phalanges, the equivalent of the human fingertip or tip of the toe, surrounded by cartilage and other specialized, blood-rich soft tissues such as the laminae. The exterior hoof wall and horn of the sole is made

Teeth.

Horses are adapted to grazing. In an adult horse, there are 12 incisors at the front of the mouth, adapted to biting off the grass or other vegetation. There are 24 teeth adapted for chewing, the premolars and molars, at the back of the mouth. Stallions and geldings have four additional teeth just behind the incisors, a type of canine teeth called "tushes". Some horses, both male and female, will also develop one to four very small vestigial teeth in front of the molars,

Digestion.

Horses are herbivores with a digestive system adapted to a forage diet of grasses and other plant material, consumed steadily throughout the day. Therefore, compared to humans, they have a relatively small stomach but very long intestines to facilitate a steady flow of nutrients. A horse will eat of

Senses.

The horses' senses are based on their status as prey animals, where they must be aware of their surroundings at all times. They have the largest eyes of any land mammal, and are lateral-eyed, meaning that their eyes are positioned on the sides of their heads. This means that horses have a range of vision of more than 350°, with approximately 65° of this being binocular vision and the remaining 285° monocular vision. Horses have excellent day and night vision, but they have two-color, or dichromatic vision; their color vision is somewhat like red-green color blindness in humans, where certain colors, especially red and related colors, appear as a shade of green.  Their sense of smell, while much better than that of humans, is not quite as good as that of a dog. It is believed to play a key role in the social interactions of horses as well as detecting other key scents in the environment. Horses have two olfactory centers. The first system is in the nostrils and nasal cavity, which analyze a wide range of odors. The second, located under the nasal cavity, are the Vomeronasal organs, also

Movement.

All horses move naturally with four basic gaits: the four-beat walk, which averages ; the two-beat trot or jog at (faster for harness racing horses); the canter or lope, a three-beat gait that is ; and the gallop. The gallop averages, but the world record for a horse galloping over a short,

Behavior.

Horses are prey animals with a strong fight-or-flight response. Their first reaction to a threat is to startle and usually flee, although they will stand their ground and defend themselves when flight is impossible or if their young are threatened. They also tend to be curious; when startled, they will often hesitate an instant to ascertain the cause of their fright, and may not always flee from something that they perceive as non-threatening. Most light horse riding breeds were developed for speed, agility, alertness and endurance; natural qualities that extend from their wild ancestors. However,

Intelligence and learning.

Studies have indicated that horses perform a number of cognitive tasks on a daily basis, meeting mental challenges that include food procurement and identification of individuals within a social system. They also have good spatial discrimination abilities. They are naturally curious and apt to investigate things they have not seen before. Studies have assessed equine intelligence in areas such as problem solving, speed of learning, and memory. Horses excel at simple learning, but also are able to use more advanced cognitive abilities that involve

Temperament.

Horses are mammals, and as such are warm-blooded, or endothermic creatures, as opposed to cold-blooded, or poikilothermic animals. However, these words have developed a separate meaning in the context of equine terminology, used to describe temperament, not body temperature. For example, the "hot-bloods", such as many race horses, exhibit more sensitivity and energy, while the "cold-bloods", such as most draft breeds, are quieter and calmer. Sometimes "hot-bloods" are classified as "light horses" or "riding horses", with the "cold-bloods" classified as "draft horses" or "work horses". "Hot blooded" breeds include "oriental horses" such as the Akhal-Teke, Arabian horse, Barb and now-extinct Turkoman horse, as well as the Thoroughbred, a breed developed in England from the older oriental breeds. Hot bloods tend to be spirited, bold, and learn quickly. They are bred for agility and speed. They tend to be physically refined—thin-skinned, slim, and long-legged. The original oriental breeds were brought to Europe from the Middle East and North Africa when European breeders wished to infuse

Sleep patterns.

Horses are able to sleep both standing up and lying down. In an adaptation from life in the wild, horses are able to enter light sleep by using a "stay apparatus" in their legs, allowing them to doze without collapsing. Horses sleep better when in groups because some animals will sleep while others stand guard to watch for predators. A horse kept alone will not sleep well because its instincts are to keep a constant eye out for danger.  Unlike humans, horses do not sleep in a solid, unbroken period of time, but take many

Taxonomy and evolution.

The horse adapted to survive in areas of wide-open terrain with sparse vegetation, surviving in an ecosystem where other large grazing animals, especially ruminants, could not. Horses and other equids are odd-toed ungulates of the order Perissodactyla, a group of mammals that was dominant during the Tertiary period. In the past, this order contained 14 families, but only three—Equidae (the horse and related species), Tapiridae (the tapir), and Rhinocerotidae (the rhinoceroses)—have survived to the present day.  The earliest known member of the family Equidae was the "Hyracotherium", which lived between 45 and 55 million years ago, during the Eocene period. It had 4 toes on each front foot, and 3 toes on each back foot. The extra toe on the front feet soon disappeared with the "Mesohippus", which lived 32 to 37 million years ago. Over time, the extra side toes shrank in size until they vanished. All that remains of them in modern horses is a set of small vestigial bones on the leg below the knee, known informally as splint bones. Their legs also lengthened as their toes disappeared until they were a hooved animal capable of running at great speed. By about 5 million years ago, the modern "Equus" had evolved. Equid teeth also evolved from browsing on soft, tropical plants to adapt to browsing of drier plant material, then to grazing of tougher plains grasses. Thus proto-horses changed from leaf-eating forest-dwellers to grass-eating inhabitants of semi-arid regions worldwide, including the steppes of Eurasia and the Great Plains of North America.  By about 15,000 years ago, "Equus ferus" was a widespread holarctic species. Horse bones from this time period, the late Pleistocene, are found in Europe, Eurasia, Beringia, and North America. Yet between 10,000 and 7,600 years ago, the horse became extinct in North America and rare elsewhere. The reasons for this extinction are not fully known, but one theory notes that extinction in North America paralleled human arrival. Another theory points to climate change, noting that approximately 12,500 years ago, the grasses characteristic of a steppe ecosystem gave way to shrub tundra, which was covered with unpalatable plants.

Wild species surviving into modern times.

A truly wild horse is a species or subspecies with no ancestors that were ever domesticated. Therefore, most "wild" horses today are actually feral horses, animals that escaped or were turned loose from domestic herds and the descendants of those animals. Only two never-domesticated subspecies, the tarpan and the Przewalski's horse, survived into recorded history and only the latter survives today.  The Przewalski's horse ("Equus ferus przewalskii"), named after the Russian explorer Nikolai Przhevalsky, is a rare Asian animal. It is also known as the Mongolian wild horse; Mongolian people know it as the "taki", and the Kyrgyz people call it a "kirtag". The subspecies was presumed extinct in the wild between 1969 and 1992, while a small breeding population survived in zoos around the world. In 1992, it was

Other modern equids.

Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus

Domestication.

Domestication of the horse most likely took place in central Asia prior to 3500 BC. Two major sources of information are used to determine where and when the horse was first domesticated and how the domesticated horse spread around the world. The first source is based on palaeological and archaeological discoveries; the second source is a comparison of DNA obtained from modern horses to that from bones and teeth of ancient horse remains.  The earliest archaeological evidence for the domestication of the horse comes from sites in Ukraine and Kazakhstan, dating to approximately 3500–4000 BC. By 3000 BC, the horse was completely domesticated and by 2000 BC there was a sharp increase in the number of horse bones found in human settlements in northwestern Europe, indicating the spread of domesticated horses throughout the continent. The most recent, but most irrefutable evidence of domestication comes from sites where horse remains were interred with chariots in graves of the Sintashta and Petrovka cultures c. 2100 BC.  Domestication is also studied by using the genetic material of present-day horses and comparing it with the genetic material present in the bones and teeth of horse remains found in archaeological and palaeological excavations. The variation in the genetic material shows that very few wild stallions contributed to the domestic horse, while many mares were part of early domesticated herds. This is reflected in the difference in genetic variation between the DNA that is passed on along the paternal, or sire line (Y-chromosome) versus that passed on along the maternal, or dam line (mitochondrial DNA). There are very low levels of Y-chromosome variability, but a great deal of genetic variation in mitochondrial DNA. There is also regional variation in mitochondrial DNA due to the inclusion of wild mares in domestic herds. Another characteristic of domestication is an increase in coat color variation. In horses, this increased dramatically between 5000 and 3000 BC.  Before the availability of DNA techniques to resolve the questions related to the domestication of the horse, various hypotheses were proposed. One classification was based on body types and conformation, suggesting the presence of four basic prototypes that had adapted to their environment prior to domestication. Another hypothesis held that the four prototypes originated from a single wild species and that all different body types were entirely a result of selective breeding after domestication. However, the lack of a detectable substructure in the horse has resulted in a rejection of both hypotheses.

Interaction with humans.

Worldwide, horses play a role within human cultures and have done so for millennia. Horses are used for leisure activities, sports, and working purposes. The Food and Agriculture Organization (FAO) estimates that in 2008, there were almost 59,000,000 horses in the world, with around 33,500,000 in the Americas, 13,800,000 in Asia and 6,300,000 in Europe and smaller portions in Africa and Oceania. There are estimated to be 9,500,000 horses in the United States alone. The American Horse Council estimates that horse-related activities have a direct impact on the economy of the United States of over $39 billion, and when indirect spending is considered, the impact is over $102 billion. In a 2004 "poll" conducted by Animal Planet, more than 50,000 viewers from 73 countries voted for the horse as the world's 4th favorite animal.  Communication between human and horse is paramount in any equestrian activity; to aid this process horses are usually ridden with a saddle on their backs to assist the rider with balance and positioning, and a bridle or related headgear to assist the rider in maintaining control. Sometimes horses are ridden without a saddle, and occasionally, horses are trained to perform without a bridle or other headgear. Many horses are also driven, which requires a harness, bridle, and some type of vehicle.

Sport.

Historically, equestrians honed their skills through games and races. Equestrian sports provided entertainment for crowds and honed the excellent horsemanship that was needed in battle. Many sports, such as dressage, eventing and show jumping, have origins in military training, which were focused on control and balance of both horse and rider. Other sports, such as rodeo, developed from practical skills such as those needed on working ranches and stations. Sport hunting from horseback evolved from earlier practical hunting techniques. Horse racing of all types evolved from impromptu competitions between riders or drivers. All forms of competition, requiring demanding and specialized skills from both horse and rider, resulted in the systematic development of specialized breeds and equipment for each sport. The popularity of equestrian sports through the centuries has resulted in the preservation of skills that would otherwise have disappeared after horses stopped being used in combat.  Horses are trained to be ridden or driven in a variety of sporting competitions. Examples include show jumping, dressage, three-day eventing,

Work.

There are certain jobs that horses do very well, and no technology has yet developed to fully replace them. For example, mounted police horses are still effective for certain types of patrol duties and crowd control. Cattle ranches still require riders on horseback to round up cattle that are scattered across remote, rugged terrain. Search and rescue organizations in some countries depend upon mounted teams to locate people, particularly hikers and children, and to provide disaster relief assistance. Horses can also be used in areas where it is necessary to avoid vehicular disruption to delicate soil, such as nature reserves. They may also

Warfare.

Horses have been used in warfare for most of recorded history. The first archaeological evidence of horses used in warfare dates to between 4000 and 3000 BC, and the use of horses in warfare was widespread by the end of

Entertainment and culture.

Modern horses are often used to reenact many of their historical work purposes. Horses are used, complete with equipment that is authentic or a meticulously recreated replica, in various live action historical reenactments of specific periods of history, especially recreations of famous battles. Horses are also used to preserve cultural traditions and for ceremonial purposes. Countries such as the United Kingdom still use horse-drawn carriages to convey royalty and other VIPs to and from certain culturally significant events. Public exhibitions are another example, such as the Budweiser Clydesdales, seen in parades and other public settings, a team of draft

Therapeutic use.

People of all ages with physical and mental disabilities obtain beneficial results from an association with horses. Therapeutic riding is used to mentally and physically stimulate disabled persons and help them improve their lives through improved balance and coordination, increased self-confidence, and a greater feeling of freedom and independence. The benefits of equestrian activity for people with disabilities has also been recognized with the addition of equestrian events to the Paralympic Games and recognition of para-equestrian events by the International Federation for Equestrian Sports (FEI).

Products.

Horses are raw material for many products made by humans throughout history, including byproducts from the slaughter of horses as well as materials collected from living horses.  Products collected from living horses include mare's milk, used by people with large horse herds, such as the Mongols, who let it ferment to produce kumis. Horse blood was once used as food by the Mongols and other nomadic tribes, who found it a convenient source of nutrition when traveling. Drinking their own horses' blood allowed the Mongols to ride for extended periods of time without stopping to eat. The drug Premarin is a mixture of estrogens extracted from the urine of

Care.

Horses are grazing animals, and their major source of nutrients is good-quality forage from hay or pasture. They can consume approximately 2% to 2.5% of their body weight in dry feed each day. Therefore, a adult horse could eat up to of food. Sometimes, concentrated feed such as grain is fed in addition to pasture or hay, especially when the animal is very active. When grain is fed, equine nutritionists recommend that 50% or more of the animal's diet by weight should still

The horse ("Equus ferus caballus") is one of two extant subspecies of "Equus ferus". It is an odd-toed ungulate mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, "Eohippus", into the large, single-toed animal of today. Humans began domesticating horses around 4000 BC, and their domestication is believed to have been widespread by 3000 BC. Horses in the subspecies "caballus" are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, as this term is used to describe horses that have never been domesticated, such as the endangered Przewalski's horse, a separate subspecies, and the only remaining true wild horse. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior.

Kůň domácí ("Equus caballus") nebo pouze kůň je domestikované zvíře patřící mezi lichokopytníky. V minulosti byli koně využíváni především pro zemědělské práce, k přepravě zboží a osob, od 20. století slouží hlavně k rekreační jízdě a sportu.


Creation.

Since 1946, the National Advisory Committee for Aeronautics (NACA) had been experimenting with rocket planes such as the supersonic Bell X-1. In the early 1950s, there was a challenge to launch an artificial satellite for the International Geophysical Year (1957–58), resulting in the American Project Vanguard among others. After the Soviet launch of the world's first artificial satellite ("Sputnik 1") on October 4, 1957, the attention of the United States turned toward its own fledgling space efforts. The US Congress, alarmed by the perceived threat to national security and technological leadership (known as the "Sputnik crisis"), urged immediate and swift action; President Dwight D. Eisenhower and his advisers counseled more deliberate measures. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever. On January 14, 1958, NACA Director Hugh Dryden published "A National Research

Leadership.

The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, and reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee usually is associated with the President's political party (Democratic or Republican), and a new administrator is usually chosen when the Presidency changes parties. The only exceptions to this have been:  The first administrator was Dr. T. Keith Glennan appointed by Republican President Dwight D. Eisenhower. During his term he brought together the disparate projects in American space development research.  The second administrator, James E. Webb (1961–1968), appointed by President John F. Kennedy, was a Democrat who first publicly served under President Harry S. Truman. In order to implement the Apollo program to achieve Kennedy's

Spaceflight programs.

NASA has conducted many crewed and uncrewed spaceflight programs throughout its history. Uncrewed programs launched the first American artificial satellites into Earth orbit for scientific and communications purposes, and sent scientific probes to explore the planets of the solar system, starting with Venus and Mars, and including "grand tours" of the outer planets. Crewed programs sent the first Americans into low Earth orbit (LEO), won the Space Race with the Soviet Union by landing twelve men on the Moon from 1969 to 1972 in the Apollo program, developed a semi-reusable LEO Space Shuttle, and developed LEO space station capability by itself and with the cooperation of several other nations including post-Soviet Russia. Some missions include both crewed and uncrewed aspects, such as the "Galileo" probe, which was deployed by astronauts in Earth orbit before being sent uncrewed to Jupiter.

Crewed programs.

The experimental rocket-powered aircraft programs started by NACA were extended by NASA as support for crewed spaceflight. This was followed by a one-man space capsule program, and in turn by a two-man capsule program. Reacting to loss of national prestige and security fears caused by early leads in space exploration by the Soviet Union, in 1961 President John F. Kennedy proposed the ambitious goal "of landing a man on the Moon by the end of [the 1960s], and returning him

X-15 rocket plane (1959–1968).

The North American X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force and Navy. The design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems. Requests for proposal were issued on December 30, 1954, for the airframe, and February 4, 1955, for the rocket engine. The airframe contract was awarded to North American Aviation in November 1955, and the XLR30 engine contract was awarded to Reaction Motors in 1956, and three planes were built. The X-15 was drop-launched from the wing of one of two NASA Boeing B-52 Stratofortresses, "NB52A" tail number 52-003, and "NB52B",

Project Mercury (1958–1963).

Shortly after the Space Race began, an early objective was to get a person into Earth orbit as soon as possible, therefore the simplest spacecraft that could be launched by existing rockets was favored. The US Air Force's Man in Space Soonest program considered many crewed spacecraft designs, ranging from rocket planes like the X-15, to small ballistic space capsules. By 1958, the space plane concepts were eliminated in favor of the ballistic capsule.  When NASA was created that same year, the Air Force program was transferred to it and renamed "Project Mercury". The first seven astronauts were selected among candidates from the Navy, Air Force and Marine test pilot programs. On May 5, 1961, astronaut Alan Shepard became the first

Project Gemini (1961–1966).

Based on studies to grow the Mercury spacecraft capabilities to long-duration flights, developing space rendezvous techniques, and precision Earth landing, Project Gemini was started as a two-man program in 1962 to overcome the Soviets' lead and to support the Apollo crewed lunar landing program, adding extravehicular activity (EVA) and rendezvous and docking to its objectives. The first crewed Gemini flight, Gemini 3, was flown by Gus Grissom and John Young

Apollo program (1961–1972).

The U.S public's perception of the Soviet lead in the Space Race (by putting the first man into space) motivated President John F. Kennedy to ask the Congress on May 25, 1961, to commit the federal government to a program to land a man on the Moon by the end of the 1960s, which effectively launched the Apollo program.  Apollo was one of the most expensive American scientific programs ever. It cost more than $20 billion in 1960s dollars or an estimated $ in present-day US dollars. (In comparison, the Manhattan Project cost roughly $, accounting for inflation.) It used the Saturn rockets as launch vehicles, which were far bigger than the rockets built for previous projects. The spacecraft was also bigger; it had two main parts, the combined command and service module (CSM) and the Apollo Lunar Module (LM). The LM was to be left on the Moon and only the command module (CM) containing the three astronauts would eventually return to Earth.  The second crewed mission, Apollo 8, brought astronauts for the first time in a flight around

Skylab (1965–1979).

Skylab was the United States' first and only independently built space station. Conceived in 1965 as a workshop to be constructed in space from a spent Saturn IB upper stage, the station was constructed on Earth and launched on May 14, 1973, atop the first two stages of a Saturn V, into a orbit inclined at 50° to the equator. Damaged during launch by the loss of its thermal protection and one electricity-generating solar panel, it was repaired to functionality by its first crew. It was

Apollo–Soyuz Test Project (1972–1975).

On May 24, 1972, US President Richard M. Nixon and Soviet Premier Alexei Kosygin signed an agreement calling for a joint crewed space mission, and declaring intent for all future international crewed spacecraft to be capable of docking with each other. This authorized the Apollo-Soyuz Test Project (ASTP), involving the

Space Shuttle program (1972–2011).

The Space Shuttle became the major focus of NASA in the late 1970s and the 1980s. Planned as a frequently launchable and mostly reusable vehicle, four Space Shuttle orbiters were built by 1985. The first to launch, "Columbia", did so on April 12, 1981, the 20th anniversary of the first known human space flight.  Its major components were a spaceplane orbiter with an external fuel tank and two solid-fuel launch rockets at its side. The external tank, which was bigger than the spacecraft itself, was the only major component that was not reused. The shuttle could orbit in altitudes of 185–643 km (115–400 miles) and carry a maximum payload (to low orbit) of 24,400 kg (54,000 lb). Missions could last from 5 to 17 days and crews could be from 2 to 8 astronauts. On 20 missions (1983–98) the Space Shuttle carried Spacelab, designed in cooperation with the European Space Agency (ESA). Spacelab was not designed for independent orbital

International Space Station (1993–present).

The International Space Station (ISS) combines NASA's "Space Station Freedom" project with the Soviet/Russian "Mir-2" station, the European "Columbus" station, and the Japanese Kibō laboratory module. NASA originally planned in the 1980s to develop "Freedom" alone, but US budget constraints led to the merger of these projects into a single multi-national program in 1993, managed by NASA, the Russian Federal Space Agency (RKA), the Japan Aerospace Exploration Agency (JAXA), the European Space Agency (ESA), and the Canadian Space Agency (CSA). The station consists

Commercial programs (2006–present).

The development of the Commercial Resupply Services (CRS) vehicles began in 2006 with the purpose of creating American commercially operated uncrewed cargo vehicles to service the ISS. The development of these vehicles was under a fixed-price, milestone-based program, meaning that each company that received a funded award had a list of milestones with a dollar value attached to them that they did not receive until after they had successfully completed the milestone. Companies were also required to raise an unspecified amount of private investment for their proposal.  On December 23, 2008, NASA awarded Commercial Resupply Services contracts to SpaceX and Orbital Sciences Corporation. SpaceX uses its Falcon 9 rocket and Dragon spacecraft. Orbital Sciences uses its Antares rocket and Cygnus spacecraft. The first Dragon resupply mission occurred in May 2012. The first Cygnus resupply mission occurred in September 2013. The CRS program now provides for all America's ISS cargo needs, with the exception of a few vehicle-specific payloads that are delivered on

Constellation program (2005–2009) and Journey To Mars (2010–2017).

While the Space Shuttle program was still suspended after the loss of "Columbia", President George W. Bush announced the Vision for Space Exploration including the retirement of the Space Shuttle after completing the International Space Station. The plan was enacted into law by the NASA Authorization Act of 2005 and directs NASA to develop and launch the Crew Exploration Vehicle (later called Orion) by 2010, return Americans to the Moon by 2020, return to Mars as feasible, repair the Hubble

Artemis program (2017–present).

Since 2017, NASA's crewed spaceflight program has been the Artemis program, which involves the help of U.S. commercial spaceflight companies and international partners such as ESA. The goal of this program is to land "the first woman and the next man" on the lunar south pole region by 2024. Artemis would be the first step towards the long-term goal of establishing a sustainable presence on the Moon, laying the foundation for private companies to build a lunar economy, and eventually sending humans to Mars.  The Orion Crew Exploration Vehicle was held over from the canceled Constellation program for Artemis. Artemis 1 is the uncrewed initial launch of SLS that would also send an Orion spacecraft on a Distant Retrograde Orbit, which is planned to launch no earlier than November 2020. NASA's next major space initiative is to be the construction of the Lunar Gateway. This initiative is to involve the construction of a

Uncrewed programs.

More than 1,000 uncrewed missions have been designed to explore the Earth and the solar system. Besides exploration, communication satellites have also been launched by NASA. The missions have been launched directly from Earth or from orbiting space shuttles, which could either deploy the satellite itself, or with a rocket stage to take it farther. The first US uncrewed satellite was Explorer 1, which started as an ABMA/JPL project during the early part of the Space Race. It was launched in January 1958, two months after Sputnik. At the creation of NASA, the Explorer project was transferred to the agency and still continues to this day. Its missions have been focusing on the Earth and the Sun, measuring magnetic fields and the solar wind, among other aspects. A more recent Earth mission, not related to the Explorer program, was the Hubble Space Telescope, which was brought into orbit in 1990. The inner Solar System has been made the goal of at least four uncrewed programs. The first was Mariner in the 1960s and 1970s, which made multiple visits to Venus and Mars and one to Mercury. Probes launched under the Mariner program were also the first

Activities (2005–2017).

NASA's ongoing investigations include in-depth surveys of Mars (Perseverance and InSight) and Saturn and studies of the Earth and the Sun. Other active spacecraft missions are "Juno" for Jupiter, "New Horizons" (for Jupiter, Pluto, and beyond), and "Dawn" for the asteroid belt. NASA continued to support "in situ" exploration beyond the asteroid belt, including Pioneer and Voyager traverses into the unexplored trans-Pluto region, and Gas Giant orbiters "Galileo" (1989–2003), "Cassini" (1997–2017), and "Juno" (2011–). In the early 2000s, NASA was put on course for the Moon, however, in 2010 this program was cancelled (see Constellation program). As part of that plan, the Shuttle was going to be replaced, however, although it was retired its replacement was also cancelled, leaving the US with no human spaceflight launcher for the first time in over three decades.  The "New Horizons" mission to Pluto was launched in 2006 and successfully performed a flyby of Pluto on July 14, 2015. The probe received a gravity assist from Jupiter in February 2007, examining some of Jupiter's inner moons and testing

NEO detection.

In 1994, there was a Congressional directive to find near-Earth objects (NEOs) larger than 1 kilometer, and 90% of 1 kilometer sized asteroids are estimated to have been found by 2010.  In 2005, the US Congress mandated NASA to achieve by the year 2020 specific levels of search completeness for discovering, cataloging, and characterizing dangerous asteroids larger than (Act of 2005, H.R. 1022; 109th), but no new funds were appropriated for this effort. As of January 2019, it is estimated about 40% of the NEOs of this size have been found, although since by its nature the exact amount of NEOs are unknown the calculations are based on predictions of how many there could be.  NEOs were defined in this case by the term "near-Earth object" as an asteroid or comet with a perihelion distance of less than 1.3 Astronomical Units from the Sun. In late 2019 the directive gained increased notoriety and NASA approved an additional space telescope in addition to the existing observatory programs.  One issue with NEO prediction is trying to estimate how many more are likely to be found In 2000, NASA reduced its estimate of the number of existing near-Earth asteroids over one kilometer in diameter from 1,000–2,000 to 500–1,000. Shortly thereafter, the LINEAR survey provided an alternative estimate of. In 2011, on the basis of NEOWISE observations, the estimated number of one-kilometer NEAs was narrowed to (of which 93% had been discovered at the time), while the number of NEAs larger than 140 meters across was estimated at. The NEOWISE estimate differed from other estimates in assuming a slightly lower average asteroid albedo, which produces larger estimated diameters for the same asteroid brightness. This resulted in 911 then known asteroids at least 1 km across, as opposed to the 830 then listed by CNEOS. In 2017, using an improved statistical method, two studies reduced the estimated number of NEAs brighter than absolute magnitude 17.75 (approximately over one kilometer in diameter) to. The estimated number of asteroids brighter than absolute magnitude of 22.0 (approximately over 140 m across) rose to, double the WISE estimate, of which about a third are known as of 2018. A problem with estimating the number of NEOs is that

Recent and planned activities.

NASA's ongoing investigations include in-depth surveys of Mars (Mars 2020 and "InSight") and Saturn and studies of the Earth and the Sun. Other active spacecraft missions are "Juno" for Jupiter, "New Horizons" (for Jupiter, Pluto, and beyond), and "Dawn" for the asteroid belt. NASA continued to support "in situ" exploration beyond the asteroid belt, including Pioneer and Voyager traverses into the unexplored trans-Pluto region, and Gas Giant orbiters "Galileo" (1989–2003), "Cassini" (1997–2017), and "Juno" (2011–).  The "New Horizons" mission to Pluto was launched in 2006 and successfully performed a flyby of Pluto on July 14, 2015. The probe received a gravity assist from Jupiter in February 2007, examining some of Jupiter's inner moons and testing on-board instruments during the flyby. On the horizon of NASA's plans is the "MAVEN"

NASA Advisory Council.

In response to the Apollo 1 accident, which killed three astronauts in 1967, Congress directed NASA to form an Aerospace Safety Advisory Panel (ASAP) to advise the NASA Administrator on safety issues and hazards in NASA's aerospace programs. In the aftermath of the Shuttle "Columbia" disaster, Congress

Directives.

Some of NASA's main directives have been the landing of a manned spacecraft on the Moon, the designing and construction of the Space Shuttle, and efforts to construct a large, crewed space station. Typically, the major directives originated from the intersection of scienctific interest and advice, political interests, federal funding concerns, and the public interest, that all together brought varying waves of effort, often heavily swayed by technical developments, funding changes, and world events. For example, in the 1980s, the Reagan administration announced a directive with a major push to build a crewed space station, given the name Space Station "Freedom". But, when the Cold War ended, Russia, the United States, and other international partners came together to design and build the International Space Station.  In the 2010s, major shifts in directives include retirement of the Space Shuttle, and the later development of a new crewed heavy lift rocket, the Space Launch System. Missions for the new Space Launch System have varied, but overall, NASA's directives are similar to the Space Shuttle program as the primary goal and desire is human spaceflight. Additionally, NASA's Space Exploration Initiative of the 1980s opened new avenues of exploration focused on other galaxies.  For the coming decades, NASA's focus has gradually shifting towards eventual exploration of Mars. One of the technological options focused on was the Asteroid Redirect Mission (ARM). ARM had largely been defunded in 2017, but the key technologies developed for ARM would be utilized for future exploration, notably on a solar electric propulsion system.  Longer project execution timelines leaves future executive administration officials to execute on a directive, which can lead to directional mismanagement.  Previously, in the early 2000s, NASA worked towards a strategic plan called the Constellation Program, but the program was defunded in the early 2010s. In the 1990s, the NASA administration adopted an approach to planning coined "Faster, Better, Cheaper".

NASA Authorization Act of 2017.

The NASA Authorization Act of 2017, which included $19.5 billion in funding for that fiscal year, directed NASA to get humans

Space Policy Directive 1.

In December 2017, on the 45th anniversary of the last crewed mission to the Lunar surface, President Donald Trump approved a directive that includes a lunar mission on the pathway to Mars and beyond.  New

Research.

NASA's Aeronautics Research Mission Directorate conducts aeronautics research.  NASA has made use of technologies such as the "Multi-Mission Radioisotope Thermoelectric Generator" (MMRTG), which is a type of Radioisotope thermoelectric generator used on space missions. Shortages of the required plutonium-238 have curtailed deep space missions since the turn of the millennium. An example of a spacecraft that was not developed because of a shortage of this material was "New Horizons 2".  The Earth science research program was created and first funded in the 1980s under the administrations of Ronald Reagan and George H.W. Bush.  NASA started an annual competition in 2014 named "Cubes in Space". It is jointly organized by NASA and the global education company "I Doodle Learning", with the objective of teaching school students aged 11–18 to design and build scientific experiments to be launched into space on a NASA rocket or balloon. On June 21, 2017 the world's smallest satellite, Kalam SAT, built by an Indian team, was launched.

Climate and other research.

NASA also researches and publishes on climate change. Its statements concur with the global scientific consensus that the global climate is warming. Bob Walker, who has advised US President Donald Trump on space issues, has advocated that NASA should focus on space exploration and that its climate study operations should be transferred to

Use of the International System of Units.

US law requires the International System of Units to be used in all U.S. Government programs,

Facilities.

NASA Headquarters in Washington, DC provides overall guidance and political leadership to the agency's ten field centers, through which all other facilities are administered. The ten field centers are:

Budget.

NASA's share of the total federal budget peaked at approximately 4.41% in 1966 during the Apollo program, then rapidly declined to approximately 1% in 1975, and stayed around that level through 1998. The percentage then gradually dropped, until leveling off again at around half a percent in 2006 (estimated in 2012 at 0.48% of the federal budget). In a March 2012 hearing of the United States Senate Science Committee, science communicator Neil deGrasse Tyson testified that "Right now, NASA's annual budget is half a penny on your tax dollar. For twice that—a penny on

Environmental impact.

The exhaust gases produced by rocket propulsion systems, both in Earth's atmosphere and in space, can adversely effect the Earth's environment. Some hypergolic rocket propellants, such as hydrazine, are highly toxic prior to combustion, but decompose into less toxic compounds after burning. Rockets using hydrocarbon fuels, such as kerosene, release carbon dioxide and soot in their exhaust. However, carbon dioxide emissions are insignificant compared to those from other sources; on average, the United States consumed of liquid fuels per day in 2014, while a single Falcon 9 rocket first stage burns around

Gallery.

Concepts.

NASA has developed oftentimes elaborate plans and

Examples of missions by target.

Here are some selected examples of missions to planetary-sized objects. Other major targets of study are the Earth itself, the Sun, and smaller Solar System bodies like asteroids and comets. In addition, the moons of the planets or body are also studied.  Examples of missions to the Sun:  Examples of missions to the Moon:  Examples of missions to small Solar System bodies (e.g. comets and asteroids):

The National Aeronautics and Space Administration (NASA; ) is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and space research.

Národní úřad pro letectví a vesmír, zkráceně NASA () je agentura federální vlády USA zodpovědná za civilní kosmický program, za všeobecný výzkum vesmíru a za výzkum v oblasti letectví.


Etymology.

In ancient literature, Goa was known by many names, such as "Gomanchala",

History.

Prehistory.

Rock art engravings found in Goa exhibit the earliest traces of human life in India. Goa, situated within the Shimoga-Goa Greenstone Belt in the Western Ghats (an area composed of metavolcanics, iron formations and ferruginous quartzite), yields evidence for Acheulean occupation. Rock art engravings (petroglyphs) are present on laterite platforms and granite boulders in Usgalimal near the west flowing Kushavati river and in Kajur. In Kajur, the rock engravings of animals, tectiforms and

Early history.

In the 3rd century BC, Goa was part of the Maurya Empire, ruled by the Buddhist emperor, Ashoka of Magadha. Buddhist monks laid the foundation of Buddhism in Goa. Between the 2nd century BC and the 6th century AD, Goa was ruled by the Bhojas of Goa. Chutus of Karwar also ruled some parts as feudatories of the Satavahanas of Kolhapur (2nd century BC to the 2nd century AD), Western Kshatrapas (around 150 AD), the Abhiras of Western Maharashtra, Bhojas of the Yadav clans of Gujarat, and the Konkan Mauryas as feudatories of the Kalachuris. The rule later passed to the Chalukyas

Portuguese period.

In 1510, the Portuguese defeated the ruling Bijapur sultan Yusuf Adil Shah with the help of a local ally, Timayya. They set up a permanent settlement in Velha Goa. This was the beginning of Portuguese colonial rule in Goa that would last for four and a half centuries,

Contemporary period.

After India gained independence from the British in 1947, India requested that Portuguese territories on the Indian subcontinent be ceded to India. Portugal refused to negotiate on the sovereignty of its Indian enclaves. On 19 December 1961, the Indian Army

Geography and climate.

Geography.

Goa encompasses an area of. It lies between the latitudes 14°53′54′′ N and 15°40′00′′ N and longitudes 73°40′33′′ E and 74°20′13′′ E.  Goa is a part of the coastal country known as the Konkan, which is an escarpment rising up to the Western Ghats range of mountains, which separate it from the Deccan Plateau. The highest point is the Sonsogor, with an altitude of. Goa has a coastline of.  Goa's seven major rivers are the Zuari, Mandovi, Terekhol, Chapora, Galgibag, Kumbarjua canal, Talpona and the Sal. The Zuari and the Mandovi are the most important rivers, interspaced by the Kumbarjua canal, forming a major estuarine complex. These rivers are fed by the Southwest

Climate.

Goa features a tropical monsoon climate under the Köppen climate classification. Goa, being in the tropical zone and near the Arabian Sea, has a hot and humid climate for most of the year. The month

Subdivisions.

The state is divided into two districts: North Goa and South Goa. Each district is administered by a district collector, appointed by the Indian government.  Panaji is the headquarters of North Goa district and is also the capital of Goa.  North Goa is further divided into three subdivisions – Panaji, Mapusa, and Bicholim; and five "talukas" (subdistricts) – Tiswadi/"Ilhas de Goa" (Panaji), Bardez (Mapusa), Pernem, Bicholim, and Sattari

Government and politics.

The politics of Goa are a result of the uniqueness of this region due to 450 years of Portuguese rule, in comparison to three centuries of British colonialism experienced by the rest of India. The Indian National Congress was unable to achieve electoral success in the first two decades after the State's incorporation into India. Instead, the state was dominated by the regional political parties like Maharashtrawadi Gomantak Party and the United Goans Party.

Government.

In the Parliament of India, Goa has two seats in the Lok Sabha (House of the People), one representing each district, and one seat in the Rajya Sabha (Council of the States).  Goa's administrative capital is Panaji in English, Pangim in Portuguese, and Ponjê in the local language. It lies on the left bank of the Mandovi. The seat of the Goa Legislative Assembly is in Porvorim, across the Mandovi from Panaji. As the state comes under the Bombay High Court, Panaji has a bench in it. Unlike other states, which follow the British Indian model of civil laws framed for individual religions, the Portuguese Goa civil code, a uniform code based on the Napoleonic code, has been retained in Goa.  Goa has a unicameral legislature, the Goa Legislative Assembly, of 40 members, headed by a speaker. The Chief Minister heads the executive, which is made up from the party or coalition elected with a majority in the legislature. The Governor, the head of

Flora and fauna.

Equatorial forest cover in Goa stands at, most of which is owned by the government. Government-owned forest is estimated at whilst private is given as. Most of the forests in the state are located in the interior eastern regions of the state. The Western Ghats, which form most of eastern Goa, have been internationally recognised as one of the biodiversity hotspots of the world. In the February 1999 issue of "National Geographic Magazine", Goa was compared with the Amazon and the Congo basins for its rich tropical biodiversity.  Goa's wildlife sanctuaries boast of more than 1512 documented species of plants, over 275 species of birds, over 48 kinds of animals and over 60 genera of reptiles.  Goa is also known for its coconut cultivation. The coconut tree has been reclassified by the government as a palm (like a grass), enabling farmers and real estate developers to clear land with fewer restrictions.  Rice is the main food crop, and pulses (legume), "Ragi" (Finger Millet) and other food crops are also grown. Main cash crops are coconut,

Economy.

Goa's state domestic product for 2017 is estimated at $11 billion at current prices. Goa is India's richest state with the highest GDP per capita – two and a half times that of the country – with one of its fastest growth rates: 8.23% (yearly average 1990–2000). Tourism is Goa's primary industry: it gets 12% of foreign tourist arrivals in India. Goa has two main tourist seasons: winter and summer. In winter, tourists from abroad (mainly Europe) come, and summer (which, in Goa, is the rainy season) sees tourists from across India. Goa's net state domestic product (NSDP) was around US$7.24 billion in 2015–16.  The land away from the coast is rich in minerals and ores, and mining forms the second largest industry. Iron, bauxite, manganese, clays, limestone, and silica are mined. The Mormugao port handled 31.69 million tonnes of cargo last year, which was 39% of India's total iron ore exports. Sesa Goa (now owned by Vedanta Resources) and Dempo are the lead miners. Rampant mining has been depleting the forest cover as well as posing a health hazard to the local

Demographics.

Population.

A native of Goa is called a Goan. Goa has a population of 1.459 million residents as of 2011, making it India's fourth smallest (after Sikkim, Mizoram and Arunachal Pradesh). The population has a growth rate of 8.23% per decade. There are 394 people for each square kilometre of land which is higher than national average 382 per km. Goa is the state with highest proportion of

Languages.

The Goa, Daman and Diu Official Language Act, 1987 makes Konkani in the Devanagari script the sole official language of Goa, but provides that Marathi may also be used "for all or any of the official purposes". Portuguese was the sole official language during Portuguese colonial rule. The government also has a policy of replying in Marathi to correspondence received in Marathi. Whilst there have been demands for according Konkani in the Roman script official status in the state, there is widespread support for keeping Konkani as the sole official language of Goa. It is however notable to mention that the entire

Religion.

According to the 2011 census, in a population of 1,458,545 people, 66.1% were Hindu, 25.1% were Christian, 8.3% were Muslim and 0.1% were Sikh.  Due to the economic decline of Portuguese India from the 18th century, there was a large-scale migration of Goan Catholics. The local Indian Christians were called "indiacatos"

Tourism.

Tourism is generally focused on the coastal areas of Goa, with decreased tourist activity inland. In 2010, there were more than 2 million tourists reported to have visited Goa, about 1.2 million of whom were from abroad., Goa was a destination of choice for Indian and foreign tourists, particularly Britons and Russians, with limited means who wanted to party. The state was hopeful that changes could be made which would attract a more upscale demographic.  Goa stands 6th in the Top 10 Nightlife cities in the world in National Geographic Travel. Notable nightclubs in Goa include Chronicle, Mambos and Sinq.  One of the biggest tourist attractions in Goa is water sports. Beaches like Baga and Calangute offer jet-skiing, parasailing, banana boat rides, water scooter rides, and more. Patnem beach in Palolem stood third in CNN Travel's Top 20 Beaches in Asia.  Over 450 years of Portuguese rule and the influence of the Portuguese culture presents to visitors to Goa a cultural environment that is not found elsewhere in India. Goa is often described as a fusion between Eastern and Western culture with Portuguese culture having a dominant position in the state be it in its architectural, cultural or social settings. The state of Goa is famous for its excellent beaches, churches, and temples. The Bom Jesus Cathedral, Fort Aguada and a new wax museum on Indian history, culture and heritage in Old Goa are other tourism destinations.

Historic sites and neighbourhoods.

Goa has two World Heritage Sites: the Bom Jesus Basilica and churches and convents of Old Goa. The basilica holds the mortal remains of St. Francis Xavier, regarded by many Catholics as the patron saint of Goa (the patron of the Archdiocese of Goa is actually Saint Joseph Vaz). These are both Portuguese-era monuments and reflect a strong European character. The relics are taken down for veneration and for public viewing, per the prerogative of the Church in Goa, not every ten or twelve years as popularly thought and propagated. The last exposition was held in 2014. Goa has the Sanctuary of Saint Joseph Vaz in Sancoale. Pilar monastery which holds novenas of Venerable Padre Agnelo Gustavo de Souza from 10 to 20 November yearly. There is a claimed Marian Apparition at the Church of

Museums and science centre.

Goa has three important museums: the Goa State Museum, the Naval Aviation Museum and the National Institute of Oceanography. The aviation museum is one of three in India

Culture.

Having been a Portuguese territory for over 450 years, Goan culture is an interesting amalgamation of both Eastern and Western styles, with the latter having a more dominant role. The tableau of Goa showcases religious harmony by focusing on the Deepastambha, the Cross and Ghode Modni followed by a chariot. Western royal attire of kings is as much part of Goa's cultural heritage as are regional dances performed depicting a unique blend of different religions and cultures of this State. Prominent local festivals are Christmas, Easter, Carnival, Diwali, Shigmo, Chavoth, Samvatsar Padvo, Dasara etc. The Goan Carnival and Christmas-new year celebrations attract many tourists.  The Gomant Vibhushan Award, the highest civilian honour of the State of Goa, is given annually by Government of Goa since 2010.

Dance and music.

Traditional Goan art forms are Dekhnni, Fugdi, Corridinho, Mando, Dulpod and Fado. Goan Catholics are fond of social gatherings and Tiatr (Teatro). As part of its Portuguese history, music is an integral part of Goan homes. It is often said that "Goans are born with

Theatre.

Natak, Tiatr (most popular) and Jagor are the chief forms of Goa's traditional performance arts. Other forms are Ranmale, Dashavatari, Kalo, Goulankala, Lalit, Kala and Rathkala. Stories from the Ramayana and the Mahabharata along with more modern social subjects are narrated with song and dance.  "Jagor", the traditional folk dance-drama, is performed by the Hindu Kunbi and Christian Gauda community of Goa, to seek the Devine Grace for protection and prosperity of the crop. Literal meaning of Jagor is "jagran" or wakeful nights. The strong belief is that the night long performance, awakens the deities once a year and they continue to remain awake throughout the year guarding the village.  Perni Jagor is the ancient mask dance – drama of Goa, performed by Perni families, using well crafted and painted wooden masks, depicting various animals, birds, supernatural power, deities, demons, and social characters.  Gauda Jagor,

Konkani cinema.

Konkani cinema is an Indian film industry, where films are made in the Konkani language, which is spoken mainly in the Indian states of Goa, Maharashtra and Karnataka and to a smaller extent in Kerala. Konkani films have been produced in Goa, Karnataka, Maharashtra and Kerala.  The first full-length Konkani film was "Mogacho Anvddo", released on 24 April 1950, and was produced and directed by A. L.Jerry Braganza, a native of Mapusa, under the banner of ETICA Pictures. Hence, 24 April is celebrated as Konkani Film Day.  Since 2004, starting from the

Food.

Rice with fish curry ("xit koddi" in Konkani) is the staple diet in Goa. Goan cuisine is famous for its rich variety of fish dishes cooked with elaborate recipes. Coconut and coconut oil are widely used in Goan cooking along with chili peppers, spices, and vinegar is used in the Catholic cuisine, giving the food a unique flavour. The Goan cuisine is heavily influenced by Portuguese cuisine.  Goan food may be divided into Goan Catholic and Goan Hindu cuisine with each showing very distinct tastes, characteristics, and cooking styles. Pork dishes such as Vindalho, Xacuti, chouriço, and Sorpotel are cooked for major occasions among the Goan Catholics. An exotic Goan vegetable stew, known as Khatkhate, is a very popular

Architecture.

The architecture of Goa is a combination of Goan, Ottoman and Portuguese styles. Since the Portuguese ruled and governed for four centuries, many churches and houses bear a striking element of the Portuguese style of architecture. Goan Hindu houses do not show

Media and communication.

Goa is served by almost all television channels available in India. Channels are received through cable in most parts of Goa. In the interior regions, channels are received via satellite dishes. Doordarshan, the national television broadcaster, has two free terrestrial channels on air.  DTH (Direct To Home) TV services are available from Dish TV, Videocon D2H, Tata Sky & DD Direct Plus. The All India Radio is the only radio channel in the state that broadcasts on both FM and AM bands. Two AM channels are broadcast, the primary channel at 1287 kHz and the Vividh Bharati channel at 1539 kHz. AIR's FM channel is called FM Rainbow and is broadcast at 105.4 MHz. A number of private FM radio channels are available, Big FM at 92.7 and Radio Indigo at 91.9 MHz. There is

Sports.

Normally other states are fond of cricket but association football is the most popular sport in Goa and is embedded in Goan culture as a result of the Portuguese influence. Its origins in the state are traced back to 1883 when the visiting Irish priest Fr. William Robert Lyons established the sport as part of a "Christian education". On 22 December 1959 the "Associação de Futebol de Goa" was formed, which continues to administer the game in the state under the new name Goa Football Association. Goa, along with West Bengal and Kerala is the locus of football in India and is home to many football clubs in the national I-League. The state's football powerhouses include Salgaocar, Dempo, Churchill Brothers, Vasco, Sporting Clube de Goa and FC Goa. The first Unity World Cup was held in Goa in 2014. The state's main football stadium, Fatorda Stadium, is located at Margao and also hosts cricket matches. The state hosted few matches of the 2017 FIFA U-17

Education.

Goa had India's earliest educational institutions built with European support. The Portuguese set up seminaries for religious education and parish schools for elementary education. Founded circa 1542 by Saint Francis Xavier, Saint Paul's College, Goa was a Jesuit school in Old Goa, which later became a college. St Paul's was once the main Jesuit institution in the whole of Asia. It housed the first printing press in India and published the first books in 1556.  Medical education began in 1801 with the offering of regular medical courses at the Royal and Military Hospital in the old City of Goa. Built in 1842 as the Escola Médico-Cirúrgica de (Nova) Goa (Medical-Surgical School of Goa), Goa Medical College is one of Asia's oldest medical colleges and has one of the oldest medical libraries (since 1845). It houses the largest hospital in Goa and continues to provide medical training to this day.  According to the 2011 census, Goa has a literacy rate of 87%, with 90% of males and 84% of females being literate. Each taluka is made up of villages, each having a school run by the government. Private schools are preferred over government-run schools. All schools come under the Goa Board of Secondary & Higher Secondary Education, whose syllabus is prescribed by the state education department. There are also a few schools that subscribe to the all-India ICSE syllabus or the NIOS syllabus. Most students in Goa complete their high school with English as the medium of instruction. Most primary schools, however, use Konkani and Marathi (in private, but government-aided schools). As is the case in most of India, enrolment for vernacular media has seen a fall in numbers in favour of English medium education. Per a report published in "The Times of India", 84%

Transportation.

Air.

Goa International Airport, is a civil enclave at INS Hansa, a Naval airfield located at Dabolim near Vasco da Gama. The airport caters to scheduled domestic and international air services. Goa has scheduled international connections to Doha, Dubai, Muscat, Sharjah

Road.

Goa's public transport largely consists of privately operated buses linking the major towns to rural areas. Government-run buses, maintained by the Kadamba Transport Corporation, link major routes (like the Panaji–Margao route) and some remote parts of the state. The Corporation owns 15 bus stands, 4 depots and one Central workshop at Porvorim and a Head Office at Porvorim. In large towns such as Panajiand Margao, intra-city buses operate. However, public transport in Goa is less developed, and residents depend heavily on their own transportation, usually motorised two-wheelers and small family cars. Goa has four National Highways passing through it. NH-66 (ex NH-17) runs along India's west coast and links Goa to Mumbai in the north and Mangalore to the south. NH-4A running across the state connects the capital Panaji to Belgaum in east, linking Goa to cities in the

Rail.

Goa has two rail lines – one run by the South Western Railway and the other by the Konkan Railway. The line run by the South Western Railway

Sea.

The Mormugao Port Trust near the city of Vasco handles mineral ore, petroleum, coal, and international containers. Much of the shipments consist of minerals and ores from Goa's hinterland.

Goa () is a state on the southwestern coast of India within the region known as the Konkan, and geographically separated from the Deccan highlands by the Western Ghats. It is surrounded by the Indian states of Maharashtra to the north and Karnataka to the east and south, with the Arabian Sea forming its western coast. It is India's smallest state by area and the fourth-smallest by population. Goa has the highest GDP per capita among all Indian states, two and a half times that of the country. It was ranked the best-placed state by the Eleventh Finance Commission for its infrastructure and ranked on top for the best quality of life in India by the National Commission on Population based on the 12 Indicators.

Goa (konkánsky गोंय, "Gómja," maráthsky गोवा, "Góvá," hindsky गोआ, "Góá," portugalsky "Goa)" je bývalá portugalská kolonie (Portugalská Indie, spolu s državami Daman a Diu), dnes nejmenší a zároveň nejvíce prosperující svazový stát Indie. Leží u pobřeží Arabského moře vklíněna mezi státy Maháráštra (na severu) a Karnátaka (na jihu). Hlavním městem je Panadží (také "Panjim", "Ponnje", dříve "Nova Goa"), další větší města jsou Margao, Mapusa a Vasco da Gama.


Architecture.

MIX is a hybrid binary–decimal computer. When programmed in binary, each byte has 6 bits (values range from 0 to 63). In decimal, each byte has 2 decimal digits (values range from 0 to 99). Bytes are grouped into words of five bytes plus a sign. Most programs written for MIX will work in either binary or decimal, so long as they do not try to store a value greater than 63 in a single byte.  A word has the range −1,073,741,823 to 1,073,741,823 (inclusive) in binary mode, and −9,999,999,999 to 9,999,999,999 (inclusive) in decimal mode. The sign-and-magnitude representation of integers in the MIX architecture distinguishes between “−0” and “+0.” This contrasts with modern computers, whose two's-complement representation of integer quantities includes a single representation for zero, but whose range for a given number of bits includes one more negative integer than the number of representable positive integers.

Registers.

There are 9 registers in MIX:  A byte is assumed to be at least 6 bits. Most instructions can specify "which" of the "fields" (bytes) of a register are to be altered, using a suffix of the form "(first:last)". The zeroth field is the one-bit sign.  MIX also records whether the previous operation overflowed, and has a one-trit comparison indicator (less than, equal to, or greater than).

Memory and input/output.

The MIX machine has 4000 words of storage (each with 5 bytes and a sign), addressed from 0 to 3999. A variety of input and output devices are also included:

Instructions.

Each machine instruction in memory occupies one word, and consists of 4 parts: the address (2 bytes and the sign of the word) in memory to read or write; an index specification (1 byte, describing which rI index register to use) to add to the address; a modification (1 byte) that specifies which parts of the register or memory location will be read or altered; and the operation code (1 byte). All operation codes have an associated mnemonic.  MIX programs frequently use self-modifying code, in particular to return from a subroutine, as MIX lacks an automatic subroutine return stack. Self-modifying code is facilitated by the modification byte, allowing the program to store data to, for example, the address part of the target instruction, leaving the rest of the instruction unmodified.  MIX programs are typically constructed using the MIXAL assembly language; for an example, see the page.

MIX is a hypothetical computer used in Donald Knuth's monograph, "The Art of Computer Programming" ("TAOCP"). MIX's model number is 1009, which was derived by combining the model numbers and names of several contemporaneous, commercial machines deemed significant by the author. Also, "MIX" read as a Roman numeral is 1009.

MIX je hypotetický počítač, který vytvořil Donald Knuth pro potřeby knihy "The Art of Computer Programming". Programovacím jazykem tohoto fiktivního procesoru je assembler MIXAL.


Validation of foreign studies and degrees

Lisbon Convention.

Mutual recognition of higher education qualifications is enshrined in the UNESCO/Council of Europe Lisbon Recognition Convention, which covers (as of February 2017) all Council of Europe members except Monaco and Greece, as well as Australia, Belarus, Holy See, Israel, Kazakhstan, Kyrghyz Republic, New Zealand and Tajikistan. The convention has also been signed, but not ratified, by Canada and the United States. Within these countries, qualifications must be recognised as equivalent unless proven otherwise, and assessments must be carried out fairly and within a reasonable time.  The convention established the European Network of Information Centres (ENIC), supplementing and expanding the National Academic Recognition Information Centre (NARIC) network established by the European Union in 1984. The ENIC-NARIC network comprises national centres for validation of degrees in member countries.

European Higher Education Area.

The European Higher Education Area consists (as of February 2017) of 48 national members (who must be signatories of the European Cultural Convention) and the European Union. It aims to promote mutual recognition of academic qualifications through alignment of national qualifications frameworks, via the Bologna Process's short cycle, first cycle (bachelor's degree), second cycle (master's degree) and third cycle (doctoral degree) framework, the European Credit Transfer and Accumulation System, and the use of Diploma Supplements.

European Qualifications Framework.

The European Qualifications Framework (EQF) is an initiative of the European Commission to provide a "translation" for national qualifications frameworks at all levels (not just higher education) and so support mobility of workers within the European Union. It originally covered the 28 EU states plus Lichtenstein and Norway, but has been opened to non-EU states, with Australia, New Zealand and Hong Kong currently going through referencing of their national frameworks to the EQF.

Mutual recognition of professional qualifications in Europe.

Mutual recognition of professional qualifications is regulated by "European Union directive 2005/36/EC of the European Parliament and of the Council of 7 September 2005 on the recognition of professional qualifications, modified by Council Directive 2006/100/EC.  Procedure:

Validation in individual countries.

Norway.

The Norwegian governmental authority for accreditation of foreign education of Norwegian citizens and foreigners, NOKUT, has sole power in these matters.

Spain.

The total validation of foreign university studies and degrees in the Spanish system consists of a complete recognition of said studies and degrees in that system. The Spanish Ministry of Education and Science is in charge of the procedure.  The academic degrees, diplomas or certificates on pharmaceutical or medical specialities which were obtained in a foreign country and which qualify the applicant in order to carry out the relevant professions in those countries can be validated as their official equivalents in the Spanish system.  The Ministry of Education and Science is only responsible for the total validation of a foreign university degree for its Spanish equivalent. Any other applications for the partial validation of studies carried out in a foreign country in order to pursue a university study course in Spain must be submitted to the Spanish university itself.

United States.

The US government does not have a specified agency for recognition and validation of foreign qualifications. Instead, responsibility falls on universities and colleges to determine the equivalence for students they admit, on employers for people they employ and on state licensing board for entry into regulated progressions. These bodies may carry out assessment themselves, or contract a private credential evaluation service.  Credential evaluation is also important for those seeking an H-1B visa, which requires a bachelor's degree or equivalent, and for some categories of permanent resident. For H-1Bs, but not permanent resident applications, experience can be counted towards equivalence at the rate of three years of experience equals one year of education.

The Validation or recognition of foreign studies and degrees is the process whereby a competent authority in one country formally recognises the value of a qualification from a foreign country. This can entail total or partial validation of foreign university and non-university studies, degrees and other qualifications. Particularly within Europe, this is covered by a number of international conventions and agreements.

Nostrifikace (z lat. "nostrum" = „naše“) je úřední uznání platnosti oprávnění získaného v zahraničí. Typicky vysvědčení, diplomu, cenných papírů, podniku atp. Typicky se nostrifikace používá při rozhodnutí o platnosti zahraničního vysvědčení domácími úřady. Tím je dosažený stupeň zahraničního vzdělání (základního, středního, vyššího odborného nebo i vysokoškolského) uznán za rovnocenný s příslušným stupněm domácího vzdělání. Stanoví-li tak mezinárodní smlouva, je namísto rozhodnutí o nostrifikaci vydáváno jen osvědčení o uznání rovnocennosti zahraničního vysvědčení.


Example: coin-operated turnstile.

An example of a simple mechanism that can be modeled by a state machine is a turnstile. A turnstile, used to control access to subways and amusement park rides, is a gate with three rotating arms at waist height, one across the entryway. Initially the arms are locked, blocking the entry, preventing patrons from passing through. Depositing a coin or token in a slot on the turnstile unlocks the arms, allowing a single customer to push through. After the customer passes through, the arms are locked again until another coin is inserted.  Considered as a state machine, the turnstile has two possible states: Locked and Unlocked. There are two possible inputs that affect its state: putting a coin in the slot (coin) and pushing the arm (push). In the locked state, pushing on the arm has no effect; no matter how many times the input push is given, it stays in the locked state. Putting a coin in – that is, giving the machine a coin input – shifts the state from Locked to Unlocked. In the unlocked state, putting additional coins in has no effect; that is, giving additional coin inputs does not change the state. However, a customer pushing through the arms, giving a push input, shifts the state back to Locked.  The turnstile state machine can be represented by a state-transition table, showing for each possible state, the transitions between them (based upon the inputs given to the machine) and the outputs resulting from each input: The turnstile state machine can also be represented by a directed graph called a state diagram "(above)". Each state is represented by a node ("circle"). Edges ("arrows") show the transitions from one state to another. Each arrow is labeled with the input that triggers that transition. An input that doesn't cause a change of state (such as a coin input in the Unlocked state) is represented by a circular arrow returning to the original state. The arrow into the Locked node from the black dot indicates it is the initial state.

Concepts and terminology.

A "state" is a description of the status of a system that is waiting to execute a "transition". A transition is a set of actions to be executed when a condition is fulfilled or when an event is received. For example, when using an audio system to listen to the radio (the system is in the "radio" state), receiving a "next" stimulus results in moving to the next station. When the system is in the "CD" state, the "next" stimulus results in moving to the next track. Identical stimuli trigger different actions depending on the current state.  In some finite-state machine representations, it is also possible to associate actions with a state:

Representations.

State/Event table.

Several state-transition table types are used. The most common representation is shown below: the combination of current state (e.g. B) and input (e.g. Y) shows the next state (e.g. C). The complete action's information is not directly described in the table and can only be added using footnotes. An FSM definition including the full actions information is possible using state tables (see also virtual finite-state machine).

UML state machines.

The Unified Modeling Language has a notation for describing state machines. UML state machines overcome the limitations of traditional finite-state machines while retaining their main benefits. UML state machines introduce the new concepts of hierarchically nested states and orthogonal regions, while extending the notion of actions. UML state machines have the characteristics of both Mealy machines and Moore machines. They support actions that depend on both the state of the system and the triggering event, as in Mealy machines, as well as entry and exit actions, which are associated with states rather than transitions, as in Moore machines.

SDL state machines.

The Specification and Description Language is a standard from ITU that includes graphical symbols to describe actions in the transition: SDL embeds basic data types called "Abstract Data Types", an action language, and an execution semantic in order to make the finite-state machine executable.

Other state diagrams.

There are a large number of variants to represent an FSM such as the one in figure 3.

Usage.

In addition to their use in modeling reactive systems presented here, finite-state machines are significant in many different areas, including electrical engineering, linguistics, computer science, philosophy, biology, mathematics, video game programming, and logic. Finite-state machines are a class of automata studied in automata theory and the theory of computation. In computer science, finite-state machines are widely used in modeling of application behavior, design of hardware digital systems, software engineering, compilers, network protocols, and the study of computation and languages.

Classification.

Finite-state machines can be subdivided into acceptors, classifiers, transducers and sequencers.

Acceptors.

Acceptors (also called detectors or recognizers) produce binary output, indicating whether or not the received input is accepted. Each state of an acceptor is either "accepting" or "non accepting". Once all input has been received, if the current state is an accepting state, the input is accepted; otherwise it is rejected. As a rule, input is a sequence of symbols (characters); actions are not used. The start state can also be an accepting state, in which case the acceptor accepts the empty string. The example in figure 4 shows an acceptor that accepts the string "nice". In this acceptor, the only accepting state is state 7.  A (possibly infinite) set of symbol sequences, called a formal language, is a regular language if there is some acceptor that accepts "exactly" that set. For example, the set of binary strings with an even number of zeroes is a regular language (cf. Fig. 5), while the set of all strings whose length is a prime number is not.  An acceptor could also be described as defining a language that would contain every string accepted by the acceptor but none of the rejected ones; that language is "accepted" by the acceptor. By definition, the languages accepted by acceptors are the regular languages.  The problem of determining the language accepted by a given acceptor is an instance of the algebraic path problem—itself a generalization of the shortest path problem to graphs with edges weighted by the elements of an (arbitrary) semiring.  An example of an accepting state appears in Fig. 5: a deterministic finite automaton (DFA) that detects whether the binary input string contains an even number of 0s.  "S" (which is also the start state) indicates the state at which an even number of 0s has been input. S is therefore an accepting state. This acceptor will finish in an accept state, if the binary string contains an even number of 0s (including any binary string containing no 0s). Examples of strings accepted by this acceptor are ε (the empty string), 1, 11, 11..., 00, 010, 1010, 10110, etc.

Classifiers.

Classifiers are a generalization of acceptors that produce "n"-ary output where "n" is strictly greater than two.

Transducers.

Transducers produce output based on a given input and/or a state using actions. They are used for control applications and in the field of computational linguistics.  In control applications, two types are distinguished:

Sequencers.

Sequencers (also called generators) are a subclass of acceptors and transducers that have a single-letter input alphabet. They produce only one sequence which can be seen as an output sequence of acceptor or transducer outputs.

Determinism.

A further distinction is between deterministic (DFA) and non-deterministic (NFA, GNFA) automata. In a deterministic automaton, every state has exactly one transition for each possible input. In a non-deterministic automaton, an input can lead to one, more than one, or no transition for a given state. The powerset construction algorithm can transform any nondeterministic automaton into a (usually more complex) deterministic automaton with identical functionality.  A finite-state machine with only one state is called a "combinatorial FSM". It only allows actions upon transition "into" a state. This concept is useful in cases where a number of finite-state machines are required to work together, and when it is convenient to consider a purely combinatorial part as a form of FSM to suit the design tools.

Alternative semantics.

There are other sets of semantics available to represent state machines. For example, there are tools for modeling and designing logic for embedded controllers. They combine hierarchical state machines (which usually have more than one current state), flow graphs, and truth tables into one language, resulting in a different formalism and set of semantics. These charts, like Harel's original state machines, support hierarchically nested states, orthogonal regions, state actions, and transition actions.

Mathematical model.

In accordance with the general classification, the following formal definitions are found.  A "deterministic finite-state machine" or "deterministic finite-state acceptor" is a quintuple formula_1, where:  For both deterministic and non-deterministic FSMs, it is conventional to allow formula_6 to be a partial function, i.e. formula_13 does not have to be defined for every combination of formula_14 and formula_15. If an FSM formula_16 is in a state formula_17, the next symbol is formula_18 and formula_13 is not defined, then formula_16 can announce an error (i.e. reject the input). This is useful in definitions of general state machines, but less useful when transforming the machine. Some algorithms in their default form may require total functions.  A finite-state machine has the same computational power as a Turing machine that is restricted such that its head may only perform "read" operations, and always has to move from left to right. That is, each formal language accepted by a finite-state machine is accepted by such a kind of restricted Turing machine, and vice versa.  A "finite-state transducer" is a sextuple formula_21, where:  If the output function depends on the state and input symbol (formula_30) that definition corresponds to the "Mealy model", and can be modelled as a Mealy machine. If the output function depends only on the state (formula_31) that definition corresponds to the "Moore model", and can be modelled as a Moore machine. A finite-state machine with no output function at all is known as a semiautomaton or transition system.  If we disregard the first output symbol of a Moore machine, formula_32, then it can be readily converted to an output-equivalent Mealy machine by setting the output function of every Mealy transition (i.e. labeling every edge) with the output symbol given of the destination Moore state. The converse transformation is less straightforward because a Mealy machine state may have different output labels on its incoming transitions (edges). Every such state needs to be split in multiple Moore machine states, one for every incident output symbol.

Optimization.

Optimizing an FSM means finding a machine with the minimum number of states that performs the same function. The fastest known algorithm doing this is the Hopcroft minimization algorithm. Other techniques include using an implication table, or the Moore reduction procedure. Additionally, acyclic FSAs can be minimized in linear time.

Implementation.

Hardware applications.

In a digital circuit, an FSM may be built using a programmable logic device, a programmable logic controller, logic gates and flip flops or relays. More specifically, a hardware implementation requires a register to store state variables, a block of combinational logic that determines the state transition, and a second block of combinational logic that determines the output of an FSM. One of the classic hardware implementations is the Richards controller.  In a "Medvedev machine", the output is directly connected to the state flip-flops minimizing the time delay between flip-flops and output.  Through state encoding for low power state machines may be optimized to minimize power consumption.

Software applications.

The following concepts are commonly used to build software applications with finite-state machines:

Finite-state machines and compilers.

Finite automata are often used in the frontend of programming language compilers. Such a frontend may comprise several finite-state machines that implement a lexical analyzer and a parser. Starting from a sequence of characters, the lexical analyzer builds a sequence of language tokens (such as reserved words, literals, and identifiers) from which the parser builds a syntax tree. The lexical analyzer and the parser handle the regular and context-free parts of the programming language's grammar.

Further reading.

Finite Markov chain processes.

Finite Markov-chain processes are also known as subshifts of finite type.

A finite-state machine (FSM) or finite-state automaton (FSA, plural: "automata"), finite automaton, or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of "states" at any given time. The FSM can change from one state to another in response to some inputs; the change from one state to another is called a "transition". An FSM is defined by a list of its states, its initial state, and the inputs that trigger each transition. Finite-state machines are of two types—deterministic finite-state machines and non-deterministic finite-state machines. A deterministic finite-state machine can be constructed equivalent to any non-deterministic one.

Konečný automat (KA, též FSM z anglického "finite state machine", či DFA z anglického "deterministic finite automaton") je teoretický výpočetní model používaný v informatice pro studium formálních jazyků. Popisuje velice jednoduchý počítač, který může být v jednom z několika stavů, mezi kterými přechází na základě symbolů, které čte ze vstupu. Množina stavů je konečná (odtud název), konečný automat nemá žádnou další paměť, kromě informace o aktuálním stavu. Konečný automat je velice jednoduchý výpočetní model, dokáže rozpoznávat pouze regulární jazyky. Konečné automaty se používají při vyhodnocování regulárních výrazů, např. jako součást lexikálního analyzátoru v překladačích. V informatice se rozlišuje kromě základního deterministického či nedeterministického automatu také automat Mealyho a Mooreův.