A satellite bus or spacecraft bus is a general model on which multiple-production satellite spacecraft are based. The bus is the infrastructure of the spacecraft providing locations for the payload. Bus-derived satellites are opposed to specially produced satellites. Bus-derived satellites are customized to customer requirements, for example with specialized sensors or transponders, in order to achieve a specific mission, they are used for geosynchronous satellites communications satellites, but are used in spacecraft which occupy lower orbits including low Earth orbit missions. Some satellite bus examples include: Boeing DS&S 702 Lockheed Martin Space Systems A2100 Alphabus INVAP ARSAT-3K Airbus D&S Eurostar ISRO's I-1K, I-2K, I-3K, I-4K, I-6K, Indian Mini Satellite bus NASA Ames MCSB SSL 1300 Orbital ATK GEOStar Mitsubishi Electric DS2000 Spacecraft Bus A bus consists of the following subsystems: Command and Data Handling System Communications system and antennas Electrical Power System Propulsion Thermal control Attitude Control System Guidance and control System Structures and trusses Life support.
Comparison of satellite buses Service module Satellite Satellite Glossary JWST Observatory: The Spacecraft Bus Spitzer's Spacecraft Bus Gunter's Space Page: Spacecraft buses
Surgut is a city in Khanty-Mansi Autonomous Okrug, located on the Ob River near its junction with the Irtysh River. It is one of the few cities in Russia to be larger than the capital or the administrative center of its federal subject in terms of population, economic activity, tourist traffic. Population: 348,643; the name of the city, according to one tradition, originates from the Khanty words "sur" and "gut". It was founded in 1594 by order of Tsar Feodor I Surgut at the end of the 16th century was a small fortress with two gates and five towers, one of which had a carriageway. In 1596 the Gostiny Dvor was built. In the 17th-18th centuries - one of the centers of the Russian development of Siberia; the fortification, built of strong wood, was located on the cape, so that it was impossible to approach it unnoticed either from the river or from the land. In the central square of the ancient settlement there was a cult place. Throughout the perimeter, the fortress was surrounded by a moat, blocked by the structures of the defensive system.
Outside the village there were special buildings - handicraft workshops, in particular, a smithy. By the name list of 1625 there were 222 servicemen living here. Subsequently, due to high mortality, the population of Surgut decreased. In 1627, 216 people lived, in 1635-200 people, in 1642-199. In the second half of the 17th century the population fluctuated around 200 people, by the end of the century there were 185 inhabitants in Surgut. Since 1782, the county town of the Surgut district of the Tobolsk province, has been formed. In 1785, the city's coat of arms was approved. At the end of the 18th century, in connection with the development of southern Siberian cities, lost its administrative significance. Since 1868 - district, since 1898 - the county town of Tobolsk province; the inhabitants of Surgut, like other Siberians, were on state security. The servants received an annual salary of money and salt; the inhabitants were supplied with weapons and ammunition. At the end of the 19th century, the population of Surgut was 1.1 thousand people.
The main occupation of the inhabitants was fishing, gathering of wild plants, cattle breeding, firewood harvesting. In 1835 the Cossack school was founded, in 1877 - the men's folk school, the women's parochial school operated, the weather station, the library-reading room, the people's house, since 1913 - the telegraph. Since November 3, 1923 the city became the center of the district of Tobolsk district of the Ural region. Since April 5, 1926, in connection with a small population, Surgut was transformed into a district village. In 1928, on the basis of the fish section, the first industrial enterprise was created - the fish canning factory. In 1929 a collective farm was organized, in 1930 - a forest site, in 1931 - a timber enterprise. In the 1930s in Surgut, attempts were made to extract minerals. October 23, 1934 is the first newspaper - "Organizer"; the urbanization of Surgut took place in the 1960s, when it became a center of oil and gas production. On June 25, 1965 the work settlement of Surgut was granted town status.
The city's holiday is celebrated annually on June 12. The current mayor is Vadim Nikolaevich Shuvalov. Ex-mayor Alexander Sidorov oversaw the construction of the Surgut Bridge, the longest one-tower cable-stayed bridge in the world. Within the framework of administrative divisions, it serves as the administrative center of Surgutsky District though it is not a part of it; as an administrative division, it is incorporated separately as the city of okrug significance of Surgut—an administrative unit with the status equal to that of the districts. As a municipal division, the city of okrug significance of Surgut is incorporated as Surgut Urban Okrug; the city is home to the largest port on the Ob River, the largest road/railway junction in northwest Siberia, two of the world's most powerful power plants, the SDPP-1 and SDPP-2, which produce over 7,200 megawatts and supply most of the region with cheap electricity. Surgut's economy is tied to the processing of natural gas; the most important enterprises are the oil firm Surgutgazprom.
The Surgut-2 Power Station providing Energy for the city is the largest gas-fired power station in the world. In Surgut, Tyumen Energy Retail Company, the largest energy sales company, is the guaranteeing supplier of electric power in the Tyumen region, ranked first in terms of the value of the productive supply of electricity among the energy distribution companies of the Urals Federal District and the second among the energy sales companies in Russia; the management office of OJSC TESS, the largest enterprise of the Urals Federal District, is located in the city in the sphere of complex service maintenance and reconstruction of electric power facilities. In addition, there are factories: stabilization of condensate, motor fuel. Enterprises food industry, timber industry. Manufacture of building materials. For 2013, the volume of shipped goods of own production, works performed and services by own strength for large and medium-sized producers of industrial products amounted to 100.7 billion rubles.
Luna 16 known as Lunnik 16, was an unmanned space mission, part of the Soviet Luna program. Luna 16 was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth after five unsuccessful similar attempts; the sample was returned from Mare Fecunditatis. It represented the first lunar sample return mission by the Soviet Union and was the third lunar sample return mission overall, following the Apollo 11 and Apollo 12 missions; the spacecraft consisted of two attached stages, an ascent stage mounted on top of a descent stage. The descent stage was a cylindrical body with four protruding landing legs, fuel tanks, a landing radar, a dual descent-engine complex. A main descent engine was used to slow the craft until it reached a cutoff point, determined by the on-board computer based on altitude and velocity. After cutoff a bank of lower-thrust jets was used for the final landing; the descent stage acted as a launch pad for the ascent stage. The ascent stage was a smaller cylinder with a rounded top.
It carried. The spacecraft descent stage was equipped with a television camera and temperature monitors, telecommunications equipment, an extendable arm with a drilling rig for the collection of a lunar soil sample; the Luna 16 automated station was launched toward the Moon from a preliminary Earth orbit and after one mid-course correction on 13 September it entered a circular 111 km with 70° inclination lunar orbit on 17 September 1970. The lunar gravity was studied from this orbit. After two orbital adjustments were performed on 18 September and 19 September the perilune was decreased to 15.1 km, as well as the inclination altered in preparation for landing. At perilune at 05:12 UT on 20 September, the main braking engine was fired, initiating the descent to the lunar surface. Six minutes at 05:18 UT, the spacecraft safely soft-landed in its target area at 0°41' south latitude and 56°18' east longitude, in the northeast area of Mare Fecunditatis 100 kilometers west of Webb crater and 150 km north of Langrenus crater.
This was the first landing made in the lunar night side. The main descent engine cut off at an altitude of 20 m, the landing jets cut off at 2 m height at a velocity less than 2.4 m/s, followed by vertical free fall. The mass of the spacecraft at landing was 1,880 kilograms. Less than an hour after landing, at 06:03 UT, an automatic drill penetrated the lunar surface to collect a soil sample. After drilling for seven minutes, the drill reached a stop at 35 centimeters depth and withdrew its sample and lifted it in an arc to the top of the spacecraft, depositing the lunar material in a small spherical capsule mounted on the main spacecraft bus; the column of regolith in the drill tube was transferred to the soil sample container. After 26 hours and 25 minutes on the lunar surface, at 07:43 UT on 21 September, the spacecraft's upper stage lifted off from the Moon; the lower stage of Luna 16 remained on the lunar surface and continued transmission of lunar temperature and radiation data. Three days on 24 September, after a direct ascent traverse with no mid-course corrections, the capsule, with its 101 grams of lunar soil, reentered Earth's atmosphere at a velocity of 11 kilometers per second.
The capsule parachuted down 80 kilometers southeast of the town of Jezkazgan in Kazakhstan at 05:25 UT on 24 September 1970. Analysis of the dark basalt material indicated a close resemblance to soil recovered by the American Apollo 12 mission. According to the Bochum Observatory in Germany and good-quality television pictures were returned by the spacecraft. Luna 16 was a landmark success for the Soviets in their deep-space exploration program. Three tiny samples of the Luna 16 soil were sold at Sotheby's auction for $442,500 in 1993. A series of 10-kopeck stamps was issued in 1970 to commemorate the flight of Luna 16 lunar probe and depicted the main stages of the programme: soft landing on Moon, launch of the lunar soil sample return capsule, parachute assisted landing back on Earth. Timeline of artificial satellites and space probes Lunar Orbiter 4 image showing the landing site of Luna 16 in Mare Fecunditatis. Zarya - Luna 16 chronology NASA NSSDC Master Catalog
Luna 3, or E-2A No.1 was a Soviet spacecraft launched in 1959 as part of the Luna programme. It was the first-ever mission to photograph the far side of the Moon and the third Soviet space probe to be sent to the neighborhood of the Moon. Though it returned rather poor pictures by standards, the historic, never-before-seen views of the far side of the Moon caused excitement and interest when they were published around the world, a tentative Atlas of the Far Side of the Moon was created after image processing improved the pictures; these views showed mountainous terrain different from the near side, only two dark, low-lying regions which were named Mare Moscoviense and Mare Desiderii. Mare Desiderii was found to be composed of a smaller mare, Mare Ingenii, several other dark craters; the reason for this difference between the two sides of the Moon is still not understood, but it seems that most of the dark lavas that flowed out to produce the maria formed under the Earth-facing half. Luna 3 was followed by the United States with Ranger 7, Ranger 8, Ranger 9.
The space probe was a wide flange near the top. The probe 120 cm at its maximum diameter at the flange. Most of the cylindric section was 95 cm in diameter; the canister was hermetically pressurized to about 0.22 atmosphere. Several solar cells were mounted on the outside of the cylinder, these provided electric power to the storage batteries inside the space probe. Shutters for thermal control were positioned along the cylinder and opened to expose a radiating surface when the internal temperature exceeded 25 °C; the upper hemisphere of the probe held the covered opening for the cameras. Four antennas protruded from the top of two from its bottom. Other scientific equipment was mounted on the outside, including micrometeoroid and cosmic ray detectors, the Yenisey-2 imaging system; the gas jets for its attitude control system were mounted on the lower end of the spacecraft. Several photoelectric cells helped maintain orientation with respect to the Moon. There were no rocket motors for course corrections.
Its interior held the cameras and the photographic film processing system, radio transmitter, storage batteries, gyroscopic units, circulating fans for temperature control. It was spin-stabilized for most of its flight, but its three-axis attitude control system was activated while taking photos. Luna 3 was radio-controlled from ground stations in the Soviet Union. After launching on a Luna 8K72 rocket over the North Pole, the Blok-E escape stage was shut down by radio control to put Luna 3 on its course to the Moon. Initial radio contact showed that the signal from the space probe was only about one-half as strong as expected, the internal temperature was rising; the spacecraft spin axis was reoriented and some equipment was shut down, resulting in a temperature drop from 40 °C to about 30 °C. At a distance of 60,000 to 70,000 km from the Moon, the orientation system was turned on and the spacecraft rotation was stopped; the lower end of the craft was pointed at the Sun, shining on the far side of the Moon.
The space probe passed within 6,200 km of the Moon near its south pole at the closest lunar approach at 14:16 UT on 6 October 1959, continued on over the far side. On 7 October, the photocell on the upper end of the space probe detected the sunlit far side of the Moon, the photography sequence was started; the first picture was taken at 03:30 UT at a distance of 63,500 km from the Moon, the last picture was taken 40 minutes from a distance of 66,700 km. A total of 29 pictures were taken. After the photography was complete the spacecraft resumed spinning, passed over the north pole of the Moon and returned towards the Earth. Attempts to transmit the pictures to the Soviet Union began on October 8 but the early attempts were unsuccessful due to the low signal strength; as Luna 3 drew closer to the Earth, a total of about 17 viewable but poor quality photographs were transmitted by 18 October. All contact with the probe was lost on 22 October 1959; the space probe was believed to have burned up in the Earth's atmosphere in March or April 1960.
Another possibility was. The gravity assist maneuver was first used in 1959 when Luna 3 photographed the far side of Earth's Moon. After launch from the Baikonur Cosmodrome, Luna 3 passed behind the Moon from south to north and headed back to Earth; the gravity of the Moon changed the spacecraft's orbit. The return orbit was calculated so that the spacecraft passed again over the Northern hemisphere where the Soviet ground stations were located; the maneuver relied on research performed under the direction of Mstislav Keldysh at the Steklov Institute of Mathematics. The purpose of this experiment was to obtain photographs of the lunar surface as the spacecraft flew by the Moon; the imaging system was designated Yenisey-2 and consisted of a dual-lens camera AFA-E1, an automatic film processing unit, a scanner. The lenses on the camera were a 200 mm focal length, f/5.6 aperture objective and a 500 mm, f/9.5 objective. The camera carried 40 frames of temperature- and radiation-resistant 35 mm isochrome film.
The 200 mm objective could image the full disk of the Moon and the 500 mm could take an image of a region on the surface. The camera was fixed in the spacecraft and pointing was achieved by rotating the craft itself. Luna 3 was the first successful three-axis stabilized spacecraft. During most of the mission, the s
Baikonur Cosmodrome Site 81
Site 81 at the Baikonur Cosmodrome is a launch site used, along with Site 200, by Proton rockets. It consists of two launch pads, areas 23 and 24. Area 24 is used for Proton-M launches, while Area 23 is inactive. Several planetary probes have been launched from Site 81. Area 23 was used to launch Mars 3, Mars 4, Mars 6 and Venera 11, whilst Area 24 was used by Mars 2, Mars 5, Mars 7, Venera 9, Venera 10 and Venera 12. Several Luna probes were launched from both areas; the Zarya and Zvezda modules of the International Space Station, as well as Salyut 2, 3 and 5, the Spektr and Priroda modules of Mir, were launched from Area 23. Area 24 was used to launch Salyut 1, 4 and 6. On 2 July 2013, a Proton-M/DM-03 launched from Site 81/24 carrying three GLONASS navigation satellites. After liftoff, the rocket began to pitch over, rolled out of control; the rocket fell close to the launch pad and exploded, the extent of any damage to Site 81 or the Baikonur Cosmodrome is unclear. Wade, Mark. "Baikonur LC81/23".
Encyclopedia Astronatuica. Archived from the original on 2 December 2008. Retrieved 2008-12-15. Wade, Mark. "Baikonur LC81/24". Encyclopedia Astronatuica. Archived from the original on 2 December 2008. Retrieved 2008-12-15
Siberia is an extensive geographical region spanning much of Eurasia and North Asia. Siberia has been a part of modern Russia since the 17th century; the territory of Siberia extends eastwards from the Ural Mountains to the watershed between the Pacific and Arctic drainage basins. The Yenisei River conditionally divides Siberia into two parts and Eastern. Siberia stretches southwards from the Arctic Ocean to the hills of north-central Kazakhstan and to the national borders of Mongolia and China. With an area of 13.1 million square kilometres, Siberia accounts for 77% of Russia's land area, but it is home to 36 million people—27% of the country's population. This is equivalent to an average population density of about 3 inhabitants per square kilometre, making Siberia one of the most sparsely populated regions on Earth. If it were a country by itself, it would still be the largest country in area, but in population it would be the world's 35th-largest and Asia's 14th-largest. Worldwide, Siberia is well known for its long, harsh winters, with a January average of −25 °C, as well as its extensive history of use by Russian and Soviet administrations as a place for prisons, labor camps, exile.
The origin of the name is unknown. Some sources say that "Siberia" originates from the Siberian Tatar word for "sleeping land". Another account sees the name as the ancient tribal ethnonym of the Sirtya, an ethnic group which spoke a Paleosiberian language; the Sirtya people were assimilated into the Siberian Tatars. The modern usage of the name was recorded in the Russian language after the Empire's conquest of the Siberian Khanate. A further variant claims; the Polish historian Chyliczkowski has proposed that the name derives from the proto-Slavic word for "north", but Anatole Baikaloff has dismissed this explanation. He said that the neighbouring Chinese and Mongolians, who have similar names for the region, would not have known Russian, he suggests that the name might be a combination of two words with Turkic origin, "su" and "bir". The region has paleontological significance, as it contains bodies of prehistoric animals from the Pleistocene Epoch, preserved in ice or in permafrost. Specimens of Goldfuss cave lion cubs and another woolly mammoth from Oymyakon, a woolly rhinoceros from the Kolyma River, bison and horses from Yukagir have been found.
The Siberian Traps were formed by one of the largest-known volcanic events of the last 500 million years of Earth's geological history. Their activity continued for a million years and some scientists consider it a possible cause of the "Great Dying" about 250 million years ago, – estimated to have killed 90% of species existing at the time. At least three species of human lived in Southern Siberia around 40,000 years ago: H. sapiens, H. neanderthalensis, the Denisovans. In 2010 DNA evidence identified the last as a separate species. Siberia was inhabited by different groups of nomads such as the Enets, the Nenets, the Huns, the Scythians and the Uyghurs; the Khan of Sibir in the vicinity of modern Tobolsk was known as a prominent figure who endorsed Kubrat as Khagan of Old Great Bulgaria in 630. The Mongols conquered a large part of this area early in the 13th century. With the breakup of the Golden Horde, the autonomous Khanate of Sibir was established in the late 15th century. Turkic-speaking Yakut migrated north from the Lake Baikal region under pressure from the Mongol tribes during the 13th to 15th century.
Siberia remained a sparsely populated area. Historian John F. Richards wrote: "... it is doubtful that the total early modern Siberian population exceeded 300,000 persons."The growing power of Russia in the West began to undermine the Siberian Khanate in the 16th century. First, groups of traders and Cossacks began to enter the area; the Russian Army was directed to establish forts farther and farther east to protect new settlers from European Russia. Towns such as Mangazeya, Tara and Tobolsk were developed, the last being declared the capital of Siberia. At this time, Sibir was the name of a fortress at Qashlik, near Tobolsk. Gerardus Mercator, in a map published in 1595, marks Sibier both as the name of a settlement and of the surrounding territory along a left tributary of the Ob. Other sources contend that the Xibe, an indigenous Tungusic people, offered fierce resistance to Russian expansion beyond the Urals; some suggest. By the mid-17th century, Russia had established areas of control; some 230,000 Russians had settled in Siberia by 1709.
Siberia was a destination for sending exiles. The first great modern change in Siberia was the Trans-Siberian Railway, constructed during 1891–1916, it linked Siberia more to the industrialising Russia of Nicholas II. Around seven million people moved to Siberia from European Russia between 1801 and 1914. From 1859 to 1917, more than half a million people migrated to the Russian Far East. Siberia has extensive natural resources. During the 20th century, large-scale exploitation of these was developed, industrial towns cropped up throughout the region. At 7:15 a.m. on 30 June 1908, millions of trees were felled near the Podkamennaya Tunguska River in central Siberia in the Tunguska Event. Most scientists believe this resulted from the air burst of a comet. Though no crater has been found, the landscape in the area still bears the scars of this event. In the early decades of the Soviet Union (
Mass concentration (astronomy)
In astronomy and astrophysics, a mass concentration is a region of a planet or moon's crust that contains a large positive gravitational anomaly. In general, the word "mascon" can be used as a noun to refer to an excess distribution of mass on or beneath the surface of an astronomical body, such as is found around Hawaii on Earth. However, this term is most used to describe a geologic structure that has a positive gravitational anomaly associated with a feature that might otherwise have been expected to have a negative anomaly, such as the "mascon basins" on the Moon. Typical examples of mascon basins on the Moon are the Imbrium, Serenitatis and Orientale impact basins, all of which exhibit significant topographic depressions and positive gravitational anomalies. Examples of mascon basins on Mars include the Argyre and Utopia basins. Theoretical considerations imply that a topographic low in isostatic equilibrium would exhibit a slight negative gravitational anomaly. Thus, the positive gravitational anomalies associated with these impact basins indicate that some form of positive density anomaly must exist within the crust or upper mantle, supported by the lithosphere.
One possibility is that these anomalies are due to dense mare basaltic lavas, which might reach up to 6 kilometers in thickness for the Moon. While these lavas contribute to the observed gravitational anomalies, uplift of the crust-mantle interface is required to account for their magnitude. Indeed, some mascon basins on the Moon do not appear to be associated with any signs of volcanic activity. Theoretical considerations in either case indicate; the huge expanse of mare basaltic volcanism associated with Oceanus Procellarum does not possess a positive gravitational anomaly. Because of its mascons, the Moon has only four "frozen orbit" inclination zones where a lunar satellite can stay in a low orbit indefinitely. Lunar subsatellites were released on two of the last three Apollo manned lunar landing missions in 1971 and 1972, it was only in 2001 that the mascons were mapped and the frozen orbits were discovered. Since their identification in 1968, the origin of the mascons beneath the surface of the Moon has been subject to much debate, but is now regarded as being the result of the impact of asteroids during the Late Heavy Bombardment.
Lunar mascons alter the local gravity above and around them sufficiently that low and uncorrected satellite orbits around the Moon are unstable on a timescale of months or years. The small perturbations in the orbits accumulate and distort the orbit enough that the satellite impacts the surface; the Luna-10 orbiter was the first artificial object to orbit the Moon and it returned tracking data indicating that the lunar gravitational field caused larger than expected perturbations due to'roughness' of the lunar gravitational field. The Lunar mascons were discovered by Paul M. Muller and William L. Sjogren of the NASA Jet Propulsion Laboratory in 1968 from a new analytic method applied to the precise navigation data from the unmanned pre-Apollo Lunar Orbiter spacecraft; this discovery observed the consistent 1:1 correlation between large positive gravity anomalies and depressed circular basins on the Moon. This fact places key limits on models attempting to follow the history of the Moon's geological development and explain the current lunar internal structures.
At that time, one of NASA's highest priority "tiger team" projects was to explain why the Lunar Orbiter spacecraft being used to test the accuracy of Project Apollo navigation were experiencing errors in predicted position of ten times the mission specification. This meant that the predicted landing areas were 100 times as large as those being defined for reasons of safety. Lunar orbital effects principally resulting from the strong gravitational perturbations of the mascons were revealed as the cause. William Wollenhaupt and Emil Schiesser of the NASA Manned Spacecraft Center in Houston worked out the "fix", first applied to Apollo 12 and permitted its landing within 163 m of the target, the previously-landed Surveyor 3 spacecraft. In May 2013 a NASA study was published with results from the twin GRAIL probes, that mapped mass concentrations on Earth's Moon. Lunar orbit § Perturbation effects