The Anik satellites are a series of geostationary communications satellites launched by Telesat Canada for television in Canada, from 1972 through 2013. Some of the satellites in the series remain operational in orbit, while others have been retired and are derelict; the naming of the satellite was determined by a national contest, was won by Julie-Frances Czapla of St. Leonard, Quebec. In Inuktitut, Anik means "little brother"; the Anik A satellites were the world's first national domestic satellites. The Anik A fleet of satellites gave CBC the ability to reach the Canadian North for the first time; each of the satellites was equipped with 12 C-band transponders, thus had the capacity for 12 colour television channels. It was launched on December 15, 1978, was the successor to the Anik A series and Hermes experimental satellite. Most of the transponders were devoted to CBC Television—East and West feed, CBC Parliamentary Television Network, CITV-TV Edmonton, CHCH Hamilton, TVOntario. CNCP Telecommunications used Anik B as a relay for its services.
The Globe and Mail used Anik B to transmit copy to printing plants across Canada. The Anik C satellite series was three times more powerful than the Anik A series, they each had sixteen Ku band transponders. Anik C-3 was used to distribute Canada's first pay television networks -- First Choice, Superchannel, C-Channel, Star Channel, AIM Pay-TV since February 1983. Anik C-3 transponder lineup: 02 - Atlantic Satellite Network 03 - Assiniboia Downs Racing Network 06 - Super Écran TV Payante 10 - Radio-Quebec 14 - La Sette 2 15 - Knowledge 16 - La Sette 1 17 - Access Alberta 18 - TFO 19 - Premier Choix/TVEC TV Payante 20 - TVOntario 23 - Superchannel 24 - TVOntario-Legislature Channel 25 - CHSC Canadian Home Shopping Club 27 - Knowledge Network 30 - First Choice 32 - CHSC Canadian Home Shopping Club Anik D1 & D2 series C-Band satellites were launched in 1982 and 1984, they were based on the Hughes 376 design. Anik E1 & E2 were launched in the early 1990s to replace Anik D1 & D2. Unlike the cylinder-shaped spin-stabilised satellites of the D-series, these were cubical, 3-axis satellites using momentum wheels for attitude stabilisation.
Anik E2 experienced an anomaly during deployment of its C-band antenna, deployed after several corrective maneuvers. On Thursday, January 20, 1994, Anik E1 and E2 suffered problems due to solar activity. E1 failed first at 12:50 EST. After a few hours, Telesat managed to restore normal functions on E1 at 20:15 EST. At 21:00 EST, both the primary and redundant E2 momentum wheels failed, thus eliminating the gyroscope effect that helps keep the satellite pointed towards Earth; the exact problem lay with the circuitry having to do with the stabilizing momentum wheel. E2 was not restored to service for five months. Telesat restored E2 by constructing special earth stations at each end of the country to monitor the satellite's position, designed specialised software to use a combination of its control jets and magnetic torquing coils to finely position the satellite. Though a small amount of extra stationkeeping fuel was needed for pitch control, the efficiencies from using the magnetic coils for roll-yaw adjustment compensated for fuel usage that would have been used in those axes, so there was an insignificant overall effect on fuel use throughout the life of the satellite.
The Anik E2 satellite continued to provide full service for 14 years. On March 26, 1996, another catastrophic failure occurred. A critical diode on Anik E1's solar panel shorted out, causing a permanent loss of half the satellite's power. Anik F1 is a Canadian geosynchronous communications satellite, launched on November 21, 2000, by an Ariane 4 rocket from the European Space Agency Guiana Space Centre at Kourou. At the moment of its launch it was the most powerful communications satellite built, it has an advanced xenon Ion thruster propulsion system and its communication "footprint" covers Central America as well as North America. It was launched by a Canadian communications company; the primary customers are the Canadian Broadcasting Corporation, Shaw Direct, CHUM Limited and Canadian Satellite Communications Inc. Manufacturer: Telesat Canada Satellite Type: Boeing Satellite Systems bus model 702 Mass: 4710 kg at launch and 3015 kg in orbit Dimensions: 40.4 m long and 9.0 m wide with the solar panels and antennas deployed.
DC power: 17.5 kW Expected lifetime: 15 years Transponders: 84 C band and Ku band Launch vehicle: Ariane 4The solar panels of Anik F1 degraded more than expected, a replacement Anik F1R was launched in 2005, with Anik F1 switching to serving only South America. Anik F1R carries a GPS/WAAS payload. At 5,900 kilograms, it is more than ten times the size of Anik A2 and is one of the largest, most powerful communications satellites built. Anik F2 is a Boeing 702-series satellite, designed to support and enhance current North American voice and broadcast services with its C- and Ku-band technologies, it is the fifteenth satellite to be launched by Telesat. With its use of Ka band technology, low-cost two-way satellite delivery will be available for wireless broadband Intern
The term apsis refers to an extreme point in the orbit of an object. It denotes either the respective distance of the bodies; the word comes via Latin from Greek, there denoting a whole orbit, is cognate with apse. Except for the theoretical possibility of one common circular orbit for two bodies of equal mass at diametral positions, there are two apsides for any elliptic orbit, named with the prefixes peri- and ap-/apo-, added in reference to the body being orbited. All periodic orbits are, according to Newton's Laws of motion, ellipses: either the two individual ellipses of both bodies, with the center of mass of this two-body system at the one common focus of the ellipses, or the orbital ellipses, with one body taken as fixed at one focus, the other body orbiting this focus. All these ellipses share a straight line, the line of apsides, that contains their major axes, the foci, the vertices, thus the periapsis and the apoapsis; the major axis of the orbital ellipse is the distance of the apsides, when taken as points on the orbit, or their sum, when taken as distances.
The major axes of the individual ellipses around the barycenter the contributions to the major axis of the orbital ellipses are inverse proportional to the masses of the bodies, i.e. a bigger mass implies a smaller axis/contribution. Only when one mass is sufficiently larger than the other, the individual ellipse of the smaller body around the barycenter comprises the individual ellipse of the larger body as shown in the second figure. For remarkable asymmetry, the barycenter of the two bodies may lie well within the bigger body, e.g. the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If the smaller mass is negligible compared to the larger the orbital parameters are independent of the smaller mass. For general orbits, the terms periapsis and apoapsis are used. Pericenter and apocenter are equivalent alternatives, referring explicitly to the respective points on the orbits, whereas periapsis and apoapsis may refer to the smallest and largest distances of the orbiter and its host.
For a body orbiting the Sun, the point of least distance is the perihelion, the point of greatest distance is the aphelion. The terms become apastron when discussing orbits around other stars. For any satellite of Earth, including the Moon, the point of least distance is the perigee and greatest distance the apogee, from Ancient Greek Γῆ, "land" or "earth". For objects in lunar orbit, the point of least distance is sometimes called the pericynthion and the greatest distance the apocynthion. Perilune and apolune are used. In orbital mechanics, the apsides technically refer to the distance measured between the barycenters of the central body and orbiting body. However, in the case of a spacecraft, the terms are used to refer to the orbital altitude of the spacecraft above the surface of the central body; these formulae characterize the pericenter and apocenter of an orbit: Pericenter Maximum speed, v per = μ a, at minimum distance, r per = a. Apocenter Minimum speed, v ap = μ a, at maximum distance, r ap = a.
While, in accordance with Kepler's laws of planetary motion and the conservation of energy, these two quantities are constant for a given orbit: Specific relative angular momentum h = μ a Specific orbital energy ε = − μ 2 a where: a is the semi-major axis: a = r per + r ap 2 μ is the standard gravitational parameter e is the eccentricity, defined as e = r ap − r per r ap + r per = 1 − 2 r ap r per + 1 Note t
Multi-Purpose Logistics Module
A Multi-Purpose Logistics Module was a large pressurized container used on Space Shuttle missions to transfer cargo to and from the International Space Station. Two MPLMs made a dozen trips in the Shuttle cargo bay and berthed to the Unity module and the Harmony module on the ISS. From there, supplies were offloaded, finished experiments and waste were reloaded; the MPLM was reberthed in the Shuttle for return to Earth. Three modules were built by the Italian Space Agency: Leonardo and Donatello; the Leonardo module was modified in 2010 to turn it into the Permanent Multipurpose Module and was permanently attached to the ISS during the STS-133 mission in March 2011. The Raffaello module in July 2011 was the last payload of a NASA Space Shuttle, it was stored at the Kennedy Space Center. The Donatello module never launched. There were 37 Space Shuttle missions to the ISS. MPLMs were flown twelve times, with SPACEHAB modules flown nine times to ISS, 25 Shuttle missions delivering construction elements, in various combinations.
An MPLM is a large cylinder equipped with a common berthing mechanism at one end, grapple fixtures to allow the Canadarm-2 to move it from the shuttle bay to a berthing port on the US Orbital Segment of the ISS. In order to provide power to equipment and experiments inside the MPLM during launch, the MPLM could be connected to the Shuttle's power supply by means of the Remotely Operated Electrical Umbilical; the umbilical was mounted on the starboard side payload bay sidewall longeron, was a folding arm umbilical that connected to the MPLM while it was in the payload bay. The arm was disconnected and retracted prior to the MPLM being removed for placement on the ISS and reconnected once the MPLM was placed back inside the payload bay; the modules were provided to NASA under contract by the Italian Space Agency. Three MPLMs were built and delivered to NASA and have names chosen by the ASI to denote some of the great talents in Italian history: Leonardo da Vinci and Donatello. Although built by ASI, the modules are owned by NASA.
In exchange for building the MPLMs, ASI receives access to U. S. research time on the ISS. The MPLMs have a heritage. In addition, ESA's Columbus module, the Harmony and Tranquility ISS modules and the ATV and Cygnus resupply craft all trace their origins to the MPLMs; the MPLM concept was created for Space Station Freedom. They were to be built by Boeing, but in 1992, the Italians announced that they would build a "Mini-Pressurized Logistics Module", able to carry 4,500 kilograms of cargo. After the 1993 redesign of Freedom, the length was doubled and it was renamed the "Multi-Purpose Logistics Module"; each empty MPLM is 21 feet long, 15 feet in diameter, weighs 4,400 kilograms, can deliver up to nine metric tons of cargo to the ISS. Donatello was a more capable module than its two siblings, as it was designed to carry payloads that required continuous power from construction through to installation on the ISS. However, Donatello was never used and some of its parts were cannibalized to convert Leonardo into the PMM.
With the end of the Space Shuttle program in 2011, the Raffaello and Leonardo modules were flown a combined total of 12 times. Since the module names are the names of three of the four Teenage Mutant Ninja Turtles, the NASA MPLM Group approached Mirage Studios artist A. C. Farley to design a logo with a ninja turtle in an astronaut flight suit. There were cloisonné pins produced, as well as embroidered patches. There are supposed to be mission jackets using this design as well; because the Ninja Turtles are copyrighted by Mirage Studios, NASA gave Mirage the copyright to the logo in exchange for the use of the studio's character on it. The following are the specifications of the MPLM: Length – 6.6 m Width – 4.57 m Mass – 4,082 kg empty. Leonardo should reenter in the atmosphere with it. Raffaello remains in storage at KSC. Axiom Space plans to use a Multi-Purpose module for the Axiom Commercial Space Station. List of Space Shuttle missions MPLM Web Site at Marshall Space Flight Center Automated Transfer Vehicle
Science Museum, London
The Science Museum is a major museum on Exhibition Road in South Kensington, London. It was founded in 1857 and today is one of the city's major tourist attractions, attracting 3.3 million visitors annually. Like other publicly funded national museums in the United Kingdom, the Science Museum does not charge visitors for admission. Temporary exhibitions, may incur an admission fee, it is part of the Science Museum Group, having merged with the Museum of Science and Industry in Manchester in 2012. A museum was founded in 1857 under Bennet Woodcroft from the collection of the Royal Society of Arts and surplus items from the Great Exhibition as part of the South Kensington Museum, together with what is now the Victoria and Albert Museum, it included a collection of machinery which became the Museum of Patents in 1858, the Patent Office Museum in 1863. This collection contained many of the most famous exhibits of. In 1883, the contents of the Patent Office Museum were transferred to the South Kensington Museum.
In 1885, the Science Collections were renamed the Science Museum and in 1893 a separate director was appointed. The Art Collections were renamed the Art Museum, which became the Victoria and Albert Museum; when Queen Victoria laid the foundation stone for the new building for the Art Museum, she stipulated that the museum be renamed after herself and her late husband. This was applied to the whole museum, but when that new building opened ten years the title was confined to the Art Collections and the Science Collections had to be divorced from it. On 26 June 1909 the Science Museum, as an independent entity, came into existence; the Science Museum's present quarters, designed by Sir Richard Allison, were opened to the public in stages over the period 1919–28. This building was known as the East Block, construction of which began in 1913 and temporarily halted by World War I; as the name suggests it was intended to be the first building of a much larger project, never realized. However, the Museum buildings were expanded over the following years.
The Science Museum now holds a collection of over 300,000 items, including such famous items as Stephenson's Rocket, Puffing Billy, the first jet engine, a reconstruction of Francis Crick and James Watson's model of DNA, some of the earliest remaining steam engines, a working example of Charles Babbage's Difference engine, the first prototype of the 10,000-year Clock of the Long Now, documentation of the first typewriter. It contains hundreds of interactive exhibits. A recent addition is the IMAX 3D Cinema showing science and nature documentaries, most of them in 3-D, the Wellcome Wing which focuses on digital technology. Entrance has been free since 1 December 2001; the museum houses some of the many objects collected by Henry Wellcome around a medical theme. The fourth floor exhibit is called "Glimpses of Medical History", with reconstructions and dioramas of the history of practised medicine; the fifth floor gallery is called "Science and the Art of Medicine", with exhibits of medical instruments and practices from ancient days and from many countries.
The collection is strong in clinical medicine and public health. The museum is a member of the London Museums of Medicine; the Science Museum has a dedicated library, until the 1960s was Britain's National Library for Science and Technology. It holds runs of periodicals, early books and manuscripts, is used by scholars worldwide, it was, for a number of years, run in conjunction with the Library of Imperial College, but in 2007 the Library was divided over two sites. Histories of science and biographies of scientists were kept at the Imperial College Library in London until February 2014 when the arrangement was terminated, the shelves were cleared and the books and journals shipped out, joining the rest of the collection, which includes original scientific works and archives, in Wroughton, Wiltshire; the Imperial College library catalogue search system now informs searchers that volumes held there are "Available at Science Museum Library Swindon Currently unavailable". A new Research Centre with library facilities is promised for late 2015 but is unlikely to have book stacks nearby.
The Science Museum's medical collections have a global coverage. Strengths include Clinical Medicine and Public Health; the new Wellcome Wing, with its focus on Bioscience, makes the Museum a leading world centre for the presentation of contemporary science to the public. Some 170,000 items which are not on current display are stored at Blythe House in West Kensington. Blythe House houses facilities including a conservation laboratory, a photographic studio, a quarantine area where newly arrived items are examined. In November 2003, the Science Museum opened the Dana Centre; the centre is an urban café annexed to the museum. It was designed by MJP Architects. In October 2007, the Science Museum cancelled a talk by the co-discoverer of the structure of DNA, James D. Watson, because he claimed that IQ test results showed blacks to have lower intelligence than whites; the decision was criticised by some scientists, including Richard Dawkins, as well as supported by other scientists, including Steven Rose.
Around 450,000 young people visit the Science Museum on educational trips or benefit from i
2004 in spaceflight
This article outlines notable events occurring in 2004 in spaceflight, including major launches and EVAs. 2004 saw the flight of the first funded manned spaceflight
Progress M-52, identified by NASA as Progress 17 or 17P, was a Progress spacecraft used to resupply the International Space Station. It was a Progress-M 11F615A55 spacecraft, with the serial number 352. Progress M-52 was launched by a Soyuz-U carrier rocket from Site 1/5 at the Baikonur Cosmodrome. Launch occurred at 19:09:18 GMT on 28 February 2005; the spacecraft docked with the Aft port of the Zvezda module at 20:10:08 GMT on 2 March. It remained docked for three and a half months before undocking at 20:16:10 GMT on 15 June 2005 to make way for Progress M-53, it was deorbited at 23:16:00 GMT on 15 June 2005. The spacecraft burned up in the atmosphere over the Pacific Ocean, with any remaining debris landing in the ocean at around 00:02:41 GMT on 16 June. Progress M-52 carried supplies to the International Space Station, including food and oxygen for the crew and equipment for conducting scientific research, it carried the TNS-0 nanosatellite, deployed from the ISS on 28 March at 08:30 GMT. List of Progress flights List of unmanned spaceflights to the ISS
Deep Impact (spacecraft)
Deep Impact was a NASA space probe launched from Cape Canaveral Air Force Station on January 12, 2005. It was designed to study the interior composition of the comet Tempel 1, by releasing an impactor into the comet. At 05:52 UTC on July 4, 2005, the Impactor collided with the comet's nucleus; the impact excavated debris from the interior of the nucleus. Photographs taken by the spacecraft showed the comet to be more dusty and less icy than had been expected; the impact generated an unexpectedly large and bright dust cloud, obscuring the view of the impact crater. Previous space missions to comets, such as Giotto, Deep Space 1, Stardust, were fly-by missions; these missions were able to photograph and examine only the surfaces of cometary nuclei, then from considerable distances. The Deep Impact mission was the first to eject material from a comet's surface, the mission garnered considerable publicity from the media, international scientists, amateur astronomers alike. Upon the completion of its primary mission, proposals were made to further utilize the spacecraft.
Deep Impact flew by Earth on December 31, 2007 on its way to an extended mission, designated EPOXI, with a dual purpose to study extrasolar planets and comet Hartley 2. Communication was unexpectedly lost in September 2013 while the craft was heading for another asteroid flyby; the Deep Impact mission was planned to help answer fundamental questions about comets, which included what makes up the composition of the comet's nucleus, what depth the crater would reach from the impact, where the comet originated in its formation. By observing the composition of the comet, astronomers hoped to determine how comets form based on the differences between the interior and exterior makeup of the comet. Observations of the impact and its aftermath would allow astronomers to attempt to determine the answers to these questions; the mission's Principal Investigator was Michael A'Hearn, an astronomer at the University of Maryland. He led the science team, which included members from Cornell University, University of Maryland, University of Arizona, Brown University, Belton Space Exploration Initiatives, JPL, University of Hawaii, SAIC, Ball Aerospace, Max-Planck-Institut für extraterrestrische Physik.
The spacecraft consists of two main sections, the 372-kilogram copper-core "Smart Impactor" that impacted the comet, the 601 kg "Flyby" section, which imaged the comet from a safe distance during the encounter with Tempel 1. The Flyby spacecraft is 1.7 meters wide and 2.3 meters high. It includes two solar panels, a debris shield, several science instruments for imaging, infrared spectroscopy, optical navigation to its destination near the comet; the spacecraft carried two cameras, the High Resolution Imager, the Medium Resolution Imager. The HRI is an imaging device that combines a visible-light camera with a filter wheel, an imaging infrared spectrometer called the "Spectral Imaging Module" or SIM that operates on a spectral band from 1.05 to 4.8 micrometres. It has been optimized for observing the comet's nucleus; the MRI is the backup device, was used for navigation during the final 10-day approach. It has a filter wheel, with a different set of filters; the Impactor section of the spacecraft contains an instrument, optically identical to the MRI, called the Impactor Targeting Sensor, but without the filter wheel.
Its dual purpose was to sense the Impactor's trajectory, which could be adjusted up to four times between release and impact, to image the comet from close range. As the Impactor neared the comet's surface, this camera took high-resolution pictures of the nucleus that were transmitted in real-time to the Flyby spacecraft before it and the Impactor were destroyed; the final image taken by the Impactor was snapped only 3.7 seconds before impact. The Impactor's payload, dubbed the "Cratering Mass", was 100% copper, with a weight of 100 kg. Including this cratering mass, copper formed 49% of total mass of the Impactor. Since copper was not expected to be found on a comet, scientists could ignore copper's signature in any spectrometer readings. Instead of using explosives, it was cheaper to use copper as the payload. Explosives would have been superfluous. At its closing velocity of 10.2 km/s, the Impactor's kinetic energy was equivalent to 4.8 metric tons of TNT more than its actual mass of only 372 kg.
The mission coincidentally shared its name with the 1998 film, Deep Impact, in which a comet strikes the Earth. Following its launch from Cape Canaveral Air Force Station pad SLC-17B at 18:47 UTC on January 12, 2005, the Deep Impact spacecraft traveled 429 million km in 174 days to reach comet Tempel 1 at a cruising speed of 28.6 km/s. Once the spacecraft reached the vicinity of the comet on July 3, 2005, it separated into the Impactor and Flyby sections; the Impactor used its thrusters to move into the path of the comet, impacting 24 hours at a relative speed of 10.3 km/s. The Impactor delivered 1.96×1010 joules of kinetic energy—the equivalent of 4.7 tons of TNT. Scientists believed that the energy of the high-velocity collision would be sufficient to excavate a crater up to 100 m wide, larger than the bowl of the Roman Colosseum; the size of the crater was still not known one year after the impact. The 2007 Stardust spacecraft's NExT mission determined the crater's diameter to be 150 meters.
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