Nepal Satellite
Nepal Satellite
Nepal 1 is the first Nepali language Satellite , Nepal 1 is primarily targeted towards homes of the Nepalese
Channel Nepal
Channel Nepal is the first Nepal i Satellite TV channel, which caters for viewers across Asia and the Pacific. views from Nepal and the …
Outline of Nepal
The Federal Democratic Republic of Nepal is a landlocked country in South Asia . … image:Satellite image of Nepal in October 2002. …
Geography of Nepal
Sandwiched between two Asian giants-- China and India -Nepal traditionally has … Image:Satellite image of Nepal in October 2002. …
Media of Nepal
Media of Nepal include radio, television, newspapers, and the internet. … a new satellite channel, was also launched in July 2007 and is …
Rakhi
Rakhi (TV series), a drama serial appearing on the Indian Zee TV satellite television network … Rakhi, Nepal
Avenues Television
Avenues Television (ATV) is a satellite television channel which has introduced itself as the first news channel of Nepal . …
Kuala Lumpur International Airport (section Satellite terminal A)
Surabaya | Satellite | Myanmar Airways International | Yangon | Satellite | Nepal Airlines | Kathmandu | Satellite | Oman Air | Muscat …
Telecommunications in Nepal
The introduction of telecommunication services in Nepal is relatively recent. … India ; satellite earth station
Stok Kangri
The elevation data was verified by GPS readings from 11 satellites at the Summit during a late July 2007 joint Nepalese-US expedition …
Palubari
a small scenic village near Sankhu in the outskirt of Kathmandu Valley of Nepal . … era, and remained as a satellite of the Sankhu village. …
Nepal Television
source | network | owner | Satellite | country NEP | broadcast … Nepal Television is the oldest and most watched television channel in …
AXN Asia
AXN Asia is a pay-tv, cable and satellite TV channel which is owned by Sony … Malaysia , Mongolia , Nepal , Pakistan , Palau , Papua New …
ITNTI
ITNTI is an ICT company that started in Nepal, and expanded globally with client … sectors ranging from agriculture to satellite communications. …
2 KB (283 words) - 07:58, 16 February 2009
Avenues TV
Avenues Television is 24 hour Nepal i news channel. … Avenues Television (ATV) is a Satellite TV Channel aimed at promoting news and …
2008 Bihar flood
embankment near Indo-Nepal border (at a place called Kusha in Nepal ) on August 18, 2008. … id 84 Satellite images of the effected area …
Dialog TV
Dialog TV is a direct broadcast satellite pay television provider based in Sri … entire of Sri Lanka and up to Nepal and neighboring …
Fox History & Entertainment
Fox History & Entertainment is a Indian cable and satellite channel launched by … This channel is also available in Nepal , Sri Lanka …
3 KB (396 words) - 17:43, 6 April 2009
History of artificial satellites
Further information: Timeline of artificial satellites and space probes
See also: Space Race
The first artificial satellite was Sputnik 1, launched by the Soviet Union on 4 October 1957, and initiating the Soviet Sputnik program, with Sergei Korolev as chief designer and Kerim Kerimov as his assistant.[4] This in turn triggered the Space Race between the Soviet Union and the United States.
Sputnik 1 helped to identify the density of high atmospheric layers through measurement of its orbital change and provided data on radio-signal distribution in the ionosphere. Because the satellite's body was filled with pressurized nitrogen, Sputnik 1 also provided the first opportunity for meteoroid detection, as a loss of internal pressure due to meteoroid penetration of the outer surface would have been evident in the temperature data sent back to Earth. The unanticipated announcement of Sputnik 1's success precipitated the Sputnik crisis in the United States and ignited the so-called Space Race within the Cold War.
Sputnik 2 was launched on November 3, 1957 and carried the first living passenger into orbit, a dog named Laika.[5]
In May, 1946, Project RAND had released the Preliminary Design of a Experimental World-Circling Spaceship, which stated, "A satellite vehicle with appropriate instrumentation can be expected to be one of the most potent scientific tools of the Twentieth Century.[6] The United States had been considering launching orbital satellites since 1945 under the Bureau of Aeronautics of the United States Navy. The United States Air Force's Project RAND eventually released the above report, but did not believe that the satellite was a potential military weapon; rather, they considered it to be a tool for science, politics, and propaganda. In 1954, the Secretary of Defense stated, "I know of no American satellite program."[7]
On July 29, 1955, the White House announced that the U.S. intended to launch satellites by the spring of 1958. This became known as Project Vanguard. On July 31, the Soviets announced that they intended to launch a satellite by the fall of 1957.
Following pressure by the American Rocket Society, the National Science Foundation, and the International Geophysical Year, military interest picked up and in early 1955 the Air Force and Navy were working on Project Orbiter, which involved using a Jupiter C rocket to launch a satellite. The project succeeded, and Explorer 1 became the United States' first satellite on January 31, 1958.[8]
In June 1961, three-and-a-half years after the launch of Sputnik 1, the Air Force used resources of the United States Space Surveillance Network to catalog 115 Earth-orbiting satellites.[9]
The largest artificial satellite currently orbiting the Earth is the International Space Station.
Space Surveillance Network
The United States Space Surveillance Network (SSN) has been tracking space objects since 1957 when the Soviets opened the space age with the launch of Sputnik I. Since then, the SSN has tracked more than 26,000 space objects orbiting Earth. The SSN currently tracks more than 8,000 man-made orbiting objects. The rest have re-entered Earth's turbulent atmosphere and disintegrated, or survived re-entry and impacted the Earth. The space objects now orbiting Earth range from satellites weighing several tons to pieces of spent rocket bodies weighing only 10 pounds. About seven percent of the space objects are operational satellites (i.e. ~560 satellites), the rest are space debris.[10] USSTRATCOM is primarily interested in the active satellites, but also tracks space debris which upon reentry might otherwise be mistaken for incoming missiles. The SSN tracks space objects that are 10 centimeters in diameter (baseball size) or large Non-Military Satellite Services
There are three basic categories of non-military satellite services:[11]
Fixed Satellite Service
Fixed satellite services handle hundreds of billions of voice, data, and video transmission tasks across all countries and continents between certain points on the earth’s surface.
In the case of News Channel while we used to Outdoor Broadcasting (OB) Van for LIVE Telecast from different places we use mobile sattelite connection and we always use two way sattelite communication like uplink and downlink both at Base Station. But on other hand if we talk about Entertainment Channel where we dont need any feed like footage and LIVE from outsources we generally use ony one way sattelite communication like uplink from the Base Station and the same time the acknowlegdement about the receiving of the signal is used to fetch from the same line of connection.
(from : Deepak Jain)
Mobile Satellite Systems
Mobile satellite systems help connect remote regions, vehicles, ships, people and aircraft to other parts of the world and/or other mobile or stationary communications units, in addition to serving as navigation systems.
Scientific Research Satellite (commercial and noncommercial)
Scientific research satellites provide us with meteorological information, land survey data (e.g., remote sensing), and other different scientific research applications such as earth science, marine science, and atmospheric research.
Types
MILSTAR: A communication satellite
* Anti-Satellite weapons/"Killer Satellites" are satellites that are armed, designed to take out enemy warheads, satellites, other space assets. They may have particle weapons, energy weapons, kinetic weapons, nuclear and/or conventional missiles and/or a combination of these weapons.
* Astronomical satellites are satellites used for observation of distant planets, galaxies, and other outer space objects.
* Biosatellites are satellites designed to carry living organisms, generally for scientific experimentation.
* Communications satellites are satellites stationed in space for the purpose of telecommunications. Modern communications satellites typically use geosynchronous orbits, Molniya orbits or Low Earth orbits.
* Miniaturized satellites are satellites of unusually low weights and small sizes.[12] New classifications are used to categorize these satellites: minisatellite (500–200 kg), microsatellite (below 200 kg), nanosatellite (below 10 kg).
* Navigational satellites are satellites which use radio time signals transmitted to enable mobile receivers on the ground to determine their exact location. The relatively clear line of sight between the satellites and receivers on the ground, combined with ever-improving electronics, allows satellite navigation systems to measure location to accuracies on the order of a few meters in real time.
* Reconnaissance satellites are Earth observation satellite or communications satellite deployed for military or intelligence applications. Little is known about the full power of these satellites, as governments who operate them usually keep information pertaining to their reconnaissance satellites classified.
* Earth observation satellites are satellites intended for non-military uses such as environmental monitoring, meteorology, map making etc. (See especially Earth Observing System.)
* Space stations are man-made structures that are designed for human beings to live on in outer space. A space station is distinguished from other manned spacecraft by its lack of major propulsion or landing facilities — instead, other vehicles are used as transport to and from the station. Space stations are designed for medium-term living in orbit, for periods of weeks, months, or even years.
* Tether satellites are satellites which are connected to another satellite by a thin cable called a tether.
* Weather satellites are primarily used to monitor Earth's weather and climate.[13]
Orbit types
Merge arrow
It has been suggested that this article or section be merged into List of orbits. (Discuss)
Main article: List of orbits
Various earth orbits to scale; cyan represents low earth orbit, yellow represents medium earth orbit, the black dashed line represents geosynchronous orbit, the green dash-dot line the orbit of Global Positioning System (GPS) satellites, and the red dotted line the orbit of the International Space Station (ISS).
The first satellite, Sputnik 1, was put into orbit around Earth and was therefore in geocentric orbit. By far this is the most common type of orbit with approximately 2456 artificial satellites orbiting the Earth. Geocentric orbits may be further classified by their altitude, inclination and eccentricity.
The commonly used altitude classifications are Low Earth Orbit (LEO), Medium Earth Orbit (MEO) and High Earth Orbit (HEO). Low Earth orbit is any orbit below 2000 km, and Medium Earth Orbit is any orbit higher than that but still below the altitude for geosynchronous orbit at 35786 km. High Earth Orbit is any orbit higher than the altitude for geosynchronous orbit.
Centric classifications
* Galactocentric orbit: An orbit about the center of a galaxy. Earth's sun follows this type of orbit about the galactic center of the Milky Way.
* Heliocentric orbit: An orbit around the Sun. In our Solar System, all planets, comets, and asteroids are in such orbits, as are many artificial satellites and pieces of space debris. Moons by contrast are not in a heliocentric orbit but rather orbit their parent planet.
* Geocentric orbit: An orbit around the planet Earth, such as the Moon or artificial satellites. Currently there are approximately 2465 artificial satellites orbiting the Earth.
* Areocentric orbit: An orbit around the planet Mars, such as moons or artificial satellites.
Altitude classifications
* Low Earth Orbit (LEO): Geocentric orbits ranging in altitude from 0–2000 km (0–1240 miles)
* Medium Earth Orbit (MEO): Geocentric orbits ranging in altitude from 2000 km (1240 miles) to just below geosynchronous orbit at 35786 km (22240 miles). Also known as an intermediate circular orbit.
* High Earth Orbit (HEO): Geocentric orbits above the altitude of geosynchronous orbit 35786 km (22240 miles).
Orbital Altitudes of several significant satellites of earth.
Inclination classifications
* Inclined orbit: An orbit whose inclination in reference to the equatorial plane is not zero degrees.
o Polar orbit: An orbit that passes above or nearly above both poles of the planet on each revolution. Therefore it has an inclination of (or very close to) 90 degrees.
o Polar sun synchronous orbit: A nearly polar orbit that passes the equator at the same local time on every pass. Useful for image taking satellites because shadows will be nearly the same on every pass.
Eccentricity classifications
* Circular orbit: An orbit that has an eccentricity of 0 and whose path traces a circle.
o Hohmann transfer orbit: An orbital maneuver that moves a spacecraft from one circular orbit to another using two engine impulses. This maneuver was named after Walter Hohmann.
* Elliptic orbit: An orbit with an eccentricity greater than 0 and less than 1 whose orbit traces the path of an ellipse.
o Geosynchronous transfer orbit: An elliptic orbit where the perigee is at the altitude of a Low Earth Orbit (LEO) and the apogee at the altitude of a geosynchronous orbit.
o Geostationary transfer orbit: An elliptic orbit where the perigee is at the altitude of a Low Earth Orbit (LEO) and the apogee at the altitude of a geostationary orbit.
o Molniya orbit: A highly elliptic orbit with inclination of 63.4° and orbital period of half of a sidereal day (roughly 12 hours). Such a satellite spends most of its time over a designated area of the planet.
o Tundra orbit: A highly elliptic orbit with inclination of 63.4° and orbital period of one sidereal day (roughly 24 hours). Such a satellite spends most of its time over a designated area of the planet.
* Hyperbolic orbit: An orbit with the eccentricity greater than 1. Such an orbit also has a velocity in excess of the escape velocity and as such, will escape the gravitational pull of the planet and continue to travel infinitely.
* Parabolic orbit: An orbit with the eccentricity equal to 1. Such an orbit also has a velocity equal to the escape velocity and therefore will escape the gravitational pull of the planet and travel until its velocity relative to the planet is 0. If the speed of such an orbit is increased it will become a hyperbolic orbit.
o Escape orbit (EO): A high-speed parabolic orbit where the object has escape velocity and is moving away from the planet.
o Capture orbit: A high-speed parabolic orbit where the object has escape velocity and is moving toward the planet.
