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33-448: Only digital radio and television channels are transmitted by the Hot Bird constellation , both free-to-air and encrypted . In addition there are a few interactive and IP services. The satellites currently operate at 13° East and are numbered 13B, 13E and 13G. The satellites have been broadcasting digital-only since TV5Monde switched off its analogue signal in 2010. Hot Bird 1

66-418: A single word. This is useful when combinations of key presses are meaningful, and is sometimes used for passing the status of modifier keys on a keyboard (such as shift and control). But it does not scale to support more keys than the number of bits in a single byte or word. Devices with many switches (such as a computer keyboard ) usually arrange these switches in a scan matrix, with the individual switches on

99-543: A switch is pressed, released, and pressed again. This polling can be done by a specialized processor in the device to prevent burdening the main CPU . When a new symbol has been entered, the device typically sends an interrupt , in a specialized format, so that the CPU can read it. For devices with only a few switches (such as the buttons on a joystick ), the status of each can be encoded as bits (usually 0 for released and 1 for pressed) in

132-669: A unified brand name effective from March 2012. This satellite became Eutelsat 9A. In 2016 it was renamed Hot Bird 13E. Hot Bird 8 was launched by Proton on 5 August 2006. With a launch mass of 4.9 tonnes, Hot Bird 8 is the largest and the most powerful broadcast satellite serving Europe . Hot Bird 9 was launched by Ariane 5 ECA in December 2008. Its entry into service enabled the Hot Bird 7A satellite to be redeployed to 9° East and rebranded Eurobird 9A, increasing capacity to 38 K u band transponders at this orbital position. From March 2012, Hot Bird 9 became Eutelsat Hot Bird 13C and during

165-582: Is a significant improvement over the bipropellant fuels of conventional chemical rockets, which feature specific impulses ~450 s. With high impulse, plasma thrusters are capable of reaching relatively high speeds over extended periods of acceleration. Ex-astronaut Franklin Chang-Diaz claims the VASIMR thruster could send a payload to Mars in as little as 39 days while reaching a maximum velocity of 34 miles per second (55 km/s). Certain plasma thrusters, such as

198-572: Is a type of electric propulsion that generates thrust from a quasi-neutral plasma . This is in contrast with ion thruster engines, which generate thrust through extracting an ion current from the plasma source, which is then accelerated to high velocities using grids/ anodes . These exist in many forms (see electric propulsion ). However, in the scientific literature, the term "plasma thruster" sometimes encompasses thrusters usually designated as " ion engines ". Plasma thrusters do not typically use high voltage grids or anodes/ cathodes to accelerate

231-630: Is designed to use PPS5000 plasma propulsion engine (developed by Safran and using xenon ) to get to geostationary orbit. Hot Bird 13G was launched by Falcon 9 Block 5 in November 2022. The satellite is very similar to Hot Bird 13F. Hot Bird 13G is active and replaces satellite 13C at orbital position 13°E. Up to 300 television and radio channels are available free-to-air . 0°0′N 13°00′E  /  0.000°N 13.000°E  / 0.000; 13.000 Digital data Digital data , in information theory and information systems ,

264-526: Is information represented as a string of discrete symbols, each of which can take on one of only a finite number of values from some alphabet , such as letters or digits. An example is a text document , which consists of a string of alphanumeric characters . The most common form of digital data in modern information systems is binary data , which is represented by a string of binary digits (bits) each of which can have one of two values, either 0 or 1. Digital data can be contrasted with analog data , which

297-436: Is rather simpler than conversion of continuous or analog information to digital. Instead of sampling and quantization as in analog-to-digital conversion , such techniques as polling and encoding are used. A symbol input device usually consists of a group of switches that are polled at regular intervals to see which switches are switched. Data will be lost if, within a single polling interval, two switches are pressed, or

330-577: Is represented by a value from a continuous range of real numbers . Analog data is transmitted by an analog signal , which not only takes on continuous values but can vary continuously with time, a continuous real-valued function of time. An example is the air pressure variation in a sound wave . The word digital comes from the same source as the words digit and digitus (the Latin word for finger ), as fingers are often used for counting. Mathematician George Stibitz of Bell Telephone Laboratories used

363-523: Is the primary carrier for BBC Persian Television . As of 2013, it was replaced by Hot Bird 10 (Hot Bird 13D). Hot Bird 7 was lost in December 2002 during the Ariane 5 ECA launch. Its replacement, Hot Bird 7A (a Spacebus 3000B3) was successfully launched on 11 March 2006. Hot Bird 7A was renamed Eurobird 9A in February 2009. In December 2011 Eutelsat announced, that their satellite assets will be renamed under

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396-531: The European Space Agency , Iranian Space Agency and Australian National University , who co-developed a double layer thruster . Some plasma engines have seen active flight time and use on missions. The first use of plasma engines was a Pulsed plasma thruster on the Soviet Zond 2 space probe which carried six PPTs that served as actuators of the attitude control system. The PPT propulsion system

429-424: The ponderomotive force which acts on any plasma or charged particle when under the influence of a strong electromagnetic energy density gradient to accelerate plasma electrons and ions in the same direction, thereby operating without a neutralizer. VASIMR, short for Variable Specific Impulse Magnetoplasma Rocket, uses radio waves to ionize a propellant into a plasma. A magnetic field then accelerates

462-463: The category of electrodeless thrusters. These thrusters support multiple propellants, making them useful for longer missions. They can be made out of simple materials including a glass soda bottle. Magnetoplasmadynamic thrusters (MPD) use the Lorentz force (a force resulting from the interaction between a magnetic field and an electric current ) to generate thrust. The electric charge flowing through

495-532: The charged particles in the plasma, but rather use currents and potentials that are generated internally to accelerate the ions, resulting in a lower exhaust velocity given the lack of high accelerating voltages. This type of thruster has a number of advantages. The lack of high voltage grids of anodes removes a possible limiting element as a result of grid ion erosion. The plasma exhaust is 'quasi-neutral', which means that positive ions and electrons exist in equal number, which allows simple ion-electron recombination in

528-555: The development of exterior support for the VASIMR to be fitted outside the International Space Station . This phase of the plan to test the VASIMR in space was expected to be conducted in 2016. Plasma engines have a much higher specific impulse ( I sp ) value than most other types of rocket technology. The VASIMR thruster can be throttled for an impulse greater than 12000 s, and hall thrusters have attained ~2000 s. This

561-469: The entire lifecycle from 'birth' to the destruction of the data. All digital information possesses common properties that distinguish it from analog data with respect to communications: Even though digital signals are generally associated with the binary electronic digital systems used in modern electronics and computing, digital systems are actually ancient, and need not be binary or electronic. Plasma propulsion engine A plasma propulsion engine

594-645: The exhaust to neutralize the exhaust plume, removing the need for an electron gun (hollow cathode). Such a thruster often generates the source plasma using radio frequency or microwave energy, using an external antenna . This fact, combined with the absence of hollow cathodes (which are sensitive to all but noble gases ), allows the possibility of using this thruster on a variety of propellants, from argon to carbon dioxide air mixtures to astronaut urine . Plasma engines are well-suited for interplanetary missions due to their high specific impulse. Many space agencies developed plasma propulsion systems, including

627-499: The input microwave power were converted to thrust. Ad Astra Rocket Company is developing the VASIMR. Canadian company Nautel is producing the 200 kW RF generators required to ionize the propellant. Some component tests and "Plasma Shoot" experiments are performed in a Liberia, Costa Rica laboratory. This project is led by former NASA astronaut Dr. Franklin Chang-Díaz (CRC-USA). The Costa Rican Aerospace Alliance announced

660-408: The intersections of x and y lines. When a switch is pressed, it connects the corresponding x and y lines together. Polling (often called scanning in this case) is done by activating each x line in sequence and detecting which y lines then have a signal , thus which keys are pressed. When the keyboard processor detects that a key has changed state, it sends a signal to the CPU indicating the scan code of

693-406: The key and its new state. The symbol is then encoded or converted into a number based on the status of modifier keys and the desired character encoding . A custom encoding can be used for a specific application with no loss of data. However, using a standard encoding such as ASCII is problematic if a symbol such as 'ß' needs to be converted but is not in the standard. It is estimated that in

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726-527: The mini-helicon, are hailed for their simplicity and efficiency. Their theory of operation is relatively simple and can use a variety of gases, or combinations. These qualities suggest that plasma thrusters have value for many mission profiles. Possibly the most significant challenge to the viability of plasma thrusters is the energy requirement. The VX-200 engine, for example, requires 200 kW electrical power to produce 5 N of thrust, or 40 kW/N. This power requirement may be met by fission reactors, but

759-475: The orbit expense of chemical rockets. Helicon plasma thrusters use low-frequency electromagnetic waves (Helicon waves) that exist inside plasma when exposed to a static magnetic field. An RF antenna that wraps around a gas chamber creates waves and excites the gas, creating plasma. The plasma is expelled at high velocity to produce thrust via acceleration strategies that require various combinations of electric and magnetic fields of ideal topology . They belong to

792-500: The plasma in the presence of a magnetic field causes the plasma to accelerate . The Lorentz force is also crucial to the operation of most pulsed plasma thrusters . Pulsed inductive thrusters (PIT) also use the Lorentz force to generate thrust, but they do not use electrodes, solving the erosion problem. Ionization and electric currents in the plasma are induced by a rapidly varying magnetic field. Electrodeless plasma thrusters use

825-511: The reactor mass (including heat rejection systems) may prove prohibitive. Another challenge is plasma erosion. While in operation the plasma can thermally ablate the walls of the thruster cavity and support structure, which can eventually lead to system failure. Due to their extremely low thrust, plasma engines are not suitable for launch-to-Earth-orbit. On average, these rockets provide about 2 pounds of thrust maximum. Plasma thrusters are highly efficient in open space, but do nothing to offset

858-496: The satellite suffered loss of power from one solar array. It was nevertheless successfully moved to 10°E, but could only operate at a reduced capacity. Since then, it is operating at 4°E under the name Eurobird 4. At last it was moved to 75°E and renamed to ABS_1B. It has reached end-of-life. Hot Bird 4 was launched by Ariane 42P on 27 February 1998 and redeployed to 7°W in July 2006, becoming Atlantic Bird 4 / Nilesat 103 . Hot Bird 5

891-413: The second quarter of 2023 Hot Bird 13G replace Hot Bird 9 at Eutelsats's 13° East position. This satellite renamed Eutelsat 10A now is located at 10.5° East for occasional feeds, data or inactive frequency Hot Bird 10 was launched by Ariane 5 ECA in February 2009 with NSS-9 , Spirale A and Spirale B. It was initially commissioned as Atlantic Bird 4A at 7°W. When Atlantic Bird 7 became operational, it

924-435: The word digital in reference to the fast electric pulses emitted by a device designed to aim and fire anti-aircraft guns in 1942. The term is most commonly used in computing and electronics , especially where real-world information is converted to binary numeric form as in digital audio and digital photography . Since symbols (for example, alphanumeric characters ) are not continuous, representing symbols digitally

957-470: The year 1986, less than 1% of the world's technological capacity to store information was digital and in 2007 it was already 94%. The year 2002 is assumed to be the year when humankind was able to store more information in digital than in analog format (the "beginning of the digital age "). Digital data come in these three states: data at rest , data in transit , and data in use . The confidentiality, integrity, and availability have to be managed during

990-401: Was launched by Ariane 44LP on 28 March 1995. The 13° east slot predates the launch, with Eutelsat I F-1 having been located there as early as 1983, and Eutelsat II F-1 having also served time at the location. It has reached end-of-life. Hot Bird 3 was launched by Ariane 44LP on 2 September 1997 and intended to be moved to 10°E to become Eurobird 10 . During the drift from 13°E to 10°E,

1023-402: Was launched by Atlas-2A on 9 October 1998 and re-located to 25.5°E and renamed Eurobird 2 . Six transponders are leased to Arabsat under the name Badr 2 , after having been called Arabsat 2D . Hot Bird 6 was launched by Atlas V 401 on 21 August 2002. Starting on 12 June 2009, the day of Iranian elections , deliberate interference affecting this satellite was traced to Iran . Hot Bird 6

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1056-464: Was renamed Eutelsat 3C and was colocated with Eutelsat 3A at 3° East. Later it became Hot Bird 13D and in 2016 Eutelsat 33E. This satellite is located at 33° East. Hot Bird 13F was launched by Falcon 9 Block 5 in October 2022. The launch mass of the satellite is 4,476 kg (9,868 lb). The satellite has been produced by Airbus Defence and Space and it's based on Eurostar Neo bus. The satellite

1089-612: Was tested for 70 minutes on the 14 December 1964 when the spacecraft was 4.2 million kilometers from Earth. In 2011, NASA partnered with Busek to launch the first hall effect thruster aboard the Tacsat-2 satellite. The thruster was the satellite's main propulsion system. The company launched another hall effect thruster that year. In 2020, research on a plasma jet was published by Wuhan University . The thrust estimates published in that work, however, were subsequently shown to be almost nine times theoretically possible levels even if 100% of

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