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Ekspress-AM4
Ekspress-AM4 was a Russian communications satellite placed into the wrong orbit from a faulty Briz-M rocket stage. This satellite was to be part of the Ekspress series of geostationary communications satellites owned by Russian Satellite Communications Company (RSCC). Proposals were made to reposition the satellite to provide broadband services to Antarctica, but ultimately the decision was made to de-orbit the satellite. On 28 March 2012, the satellite splashed into the Pacific Ocean. Satellite description The total mass of the Ekspress-AM4 satellite was , and the satellite had 63 transponders. The onboard antennas were capable of broadcasting in the C-band, Ku-band, L-band, and Ka-band. The satellite's orbit was measured at 695 by 20239 km altitude, with an inclination orbit of 51.1°. Though the satellite was placed in the wrong orbit, there was no damage to the satellite, meaning that it became the subject of numerous reuse proposals. Launch The Ekspress-AM4 sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ekspress-MD1
Ekspress-MD1 ( Russian: ), was a Russian geostationary communications satellite operated by Russian Satellite Communications Company (RSCC) and designed and manufactured by Khrunichev State Research and Production Space Center on the Yakhta satellite bus for RSCC's Ekspress series. It massed at launch, had a power production capacity of 1300 watts with a C-band and L-band payload. It was successfully launched along Ekspress-AM4 aboard a Proton-M / Briz-M from Baikonur on 11 February 2009. It was commissioned in the 80° East orbital position. The satellite failed on 4 July 2013, well short of its design life, for which RSCC collected the insurance. Satellite description Ekspress-MD1 was a geostationary communications satellite developed by Khrunichev State Research and Production Space Center on the Yakhta setellite bus. It is a small, three axis stabilized, satellite bus designed for direct geostationary orbit and as such it lacked an apogee kick motor. It was d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Ekspress Satellites
Ekspress (Russian: , ''literally'' Express) is a communication and broadcasting system developed and operated by Russian Satellite Communications Company (RSCC). It is the largest network of Russia and its slots cover an arc in geostationary orbit from 14.0° West to 145.0° East. This allows it to cover the whole territory of Russia, the CIS, Europe, the Middle East, Africa, the Asia-Pacific region, North and South America, and Australia. The only other Russian civilian satellite operator is Gazprom Space Systems with its Yamal constellation. Ekspress satellite series While the Ekspress constellation started with a single model, during the years it has used many suppliers and many models. See also * Telecommunications in Russia * Russian Satellite Communications Company – Satellite communication company of the Ministry of Telecom and Mass Communications of the Russian Federation and owner of the Ekspress satellite series. * Gazprom Space Systems – Satellite commu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton-M
The Proton-M, (Протон-М) GRAU index 8K82M or , is an expendable Russian heavy-lift launch vehicle derived from the Soviet-developed Proton. It is built by Khrunichev, and launched from sites 81 and 200 at the Baikonur Cosmodrome in Kazakhstan. Commercial launches are marketed by International Launch Services (ILS), and generally use Site 200/39. The first Proton-M launch occurred on 7 April 2001. Proton flew its most recent mission on 13 December 2021, launching two Ekspress communication satellites into geostationary orbit. As of August 2020, a number of Roscosmos and other Russian government missions remain on Proton launch manifest. Vehicle description The Proton-M launch vehicle consists of three stages; all of them powered by liquid rocket engines using the hypergolic propellant combination of dinitrogen tetroxide as the oxidizer, and unsymmetrical dimethylhydrazine for fuel. The first stage is unique in that it consists of a central cylindrical oxidizer tank ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Briz (rocket Stage)
The Briz-K, Briz-KM and Briz-M (russian: Бриз-К, КM and M meaning ''Breeze-K, KM and M'') are Russian liquid-propellant rocket orbit insertion upper stages manufactured by Khrunichev State Research and Production Space Center and used on the Proton-M and Angara A5. The upper stages were also used on Rokot, one of Russia's smaller launchers, before its retirement in 2019. Characteristics Briz-K and Briz-KM Briz-K, GRAU index 14S12, is a single-piece structure with a conical tank compartment and the engine located in a recess in the fuel tank. Briz-KM (GRAU index 14S45) is an improved version of Briz-K. The Briz-K and Briz-KM were used as a third stage of the Rokot launch vehicles. Briz-M Briz-M, GRAU index 14S43, is designed for injecting large payloads into a low, medium-height or high geosynchronous orbit. Briz-M is a twin upper stage consisting of a core module (using Briz-KM as the baseline) and a jettisonable add-on toroidal tank surrounding the core. It is po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ekspress-MD2
Ekspress-MD2 is a Russian communications satellite which was lost due to a launch failure on 6 August 2012. Equipped with eight C-band transponders and 1 L-band transponder, it was intended to be located in geostationary orbit at a longitude of 145° East. It was the second Ekspress-MD satellite to be launched, following Ekspress-MD1 in 2009. Launch Ekspress-MD2 was launched atop a Proton-M launch vehicle with a Briz-M upper stage on 6 August 2012 at 19:31:00 UTC. The Indonesian Telkom-3 satellite was also carried aboard the launch vehicle. Launch occurred from Site 81/24 at the Baikonur Cosmodrome in Kazakhstan. The first three stages of the Proton launched worked as expected and the satellites were attached to the Briz-M upper stage which would transfer them into geosynchronous orbit. The Briz-M undertakes a series of four burns with coasting stages in order to do this. The third burn was due to be 18 minutes long but the engines cut out after 7 seconds, leaving the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ku Band
The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally german: Kurz-unten), because it is the lower part of the original NATO K band, which was split into three bands (Ku, K, and Ka) because of the presence of the atmospheric water vapor resonance peak at 22.24 GHz, (1.35 cm) which made the center unusable for long range transmission. In radar applications, it ranges from 12 to 18 GHz according to the formal definition of radar frequency band nomenclature in IEEE Standard 521–2002. Ku band is primarily used for satellite communications, most notably the downlink used by direct broadcast satellites to broadcast satellite television, and for specific applications such as NASA's Tracking Data Relay Satellite used for International Space Station (ISS) communications and SpaceX Starlink satellites. Ku band satellites are also used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continents of Asia and Oceania in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about 32% of its total surface area, larger than Earth's entire land area combined .Pacific Ocean . '' Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the |
Atmospheric Entry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass (ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic speed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadband
In telecommunications, broadband is wide bandwidth data transmission which transports multiple signals at a wide range of frequencies and Internet traffic types, that enables messages to be sent simultaneously, used in fast internet connections. The medium can be coaxial cable, optical fiber, wireless Internet (radio), twisted pair or satellite. In the context of Internet access, broadband is used to mean any high-speed Internet access that is always on and faster than dial-up access over traditional analog or ISDN PSTN services. Overview Different criteria for "broad" have been applied in different contexts and at different times. Its origin is in physics, acoustics, and radio systems engineering, where it had been used with a meaning similar to "wideband", or in the context of audio noise reduction systems, where it indicated a single-band rather than a multiple-audio-band system design of the compander. Later, with the advent of digital telecommunications, the term was mainly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multistage Rocket
A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or attached next to each other. Two-stage rockets are quite common, but rockets with as many as five separate stages have been successfully launched. By jettisoning stages when they run out of propellant, the mass of the remaining rocket is decreased. Each successive stage can also be optimized for its specific operating conditions, such as decreased atmospheric pressure at higher altitudes. This ''staging'' allows the thrust of the remaining stages to more easily accelerate the rocket to its final speed and height. In serial or tandem staging schemes, the first stage is at the bottom and is usually the largest, the second stage and subseq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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