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USA-246
USA-246, also known as Advanced Extremely High Frequency 3 or AEHF-3, is a military communications satellite operated by the United States Air Force. It is the third of six satellites to be launched as part of the Advanced Extremely High Frequency program, which replaced the earlier Milstar system. Satellite The USA-246 satellite was constructed by Lockheed Martin Space, and is based on the A2100 satellite bus. The satellite has a mass of and a design life of 14 years. It will be used to provide super high frequency (SHF) and extremely high frequency (EHF) communications for the United States Armed Forces, as well as those of the United Kingdom, the Netherlands, and Canada. Launch USA-246 was launched by United Launch Alliance, aboard an Atlas V 531 flying from Space Launch Complex 41 (SLC-41) at the Cape Canaveral Air Force Station (CCAFS). After a number of weather-related delays, the launch occurred at 08:10:00 UTC on 18 September 2013, placing the satelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Extremely High Frequency
Advanced Extremely High Frequency (AEHF) is a constellation of communications satellites operated by the United States Space Force. They are used to relay secure communications for the United States Armed Forces, the British Armed Forces, the Canadian Armed Forces, the Netherlands Armed Forces and the Australian Defence Force. The system consists of six satellites in geostationary orbits. The final satellite was launched on 26 March 2020. AEHF is backward compatible with, and replaces, the older Milstar system and will operate at 44 GHz uplink (extremely high frequency (EHF) band) and 20 GHz downlink (super high frequency (SHF) band). The AEHF system is a joint service communications system that provides survivable, global, secure, protected, and jam-resistant communications for high-priority military ground, sea and air assets. Overview AEHF satellites use many narrow spot beams directed towards the Earth to relay communications to and from users. Crosslinks between the satel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas V
Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Martin and Boeing. Atlas V is also a major NASA launch vehicle. It is America's longest-serving active rocket. In August 2021, ULA announced that Atlas V would be retired, and all 29 remaining launches had been sold. , 19 launches remain. Each Atlas V launch vehicle consists of two main stages. The first stage (rocketry), first stage is powered by a Russian RD-180 engine manufactured by NPO Energomash, Energomash and burning kerosene and liquid oxygen. The Centaur (rocket stage), Centaur upper stage is powered by one or two American RL10 engine(s) manufactured by Aerojet Rocketdyne and burns liquid hydrogen and liquid oxygen. The Star 48 upper stage was used on the ''New Horizons'' mission as a third stage. strap-on booster, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USA Satellites
This is a list of satellites and spacecraft which have been given USA designations by the United States Air Force. These designations have been applied to most United States military satellites since 1984, and replaced the earlier OPS designation. As of June 2022, USA designations have been assigned to 331 space satellites. There is not always a one-to-one mapping between launch vehicles and mission spacecraft. This can occasionally result in gaps when maintaining records that incorrectly make that assumption, such as the "missing" entries for USA-163 (which are, symmetrically, contemporary with confusion over "splitting" spacecraft tracks). List See also * List of NRO launches References External links Directory of U.S. Military Rockets and Missiles - Satellite Launch ListEncyclopedia Astronautica {{Space exploration lists and timelines USA The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a cou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2013 In Spaceflight
In 2013, the maiden spaceflight of the Orbital Sciences' Antares launch vehicle, designated ''A-ONE'', took place on 13 April. Orbital Science also launched its first spacecraft, Cygnus, that docked with the International Space Station in late September 2013. A total of 81 orbital launches were attempted in 2013, of which 77 were successful, one was partially successful and three were failures. The year also saw eleven EVAs by ISS astronauts. The majority of the year's orbital launches were conducted by Russia, the United States and China, with 31, 19 and 15 launches respectively. Overview India's Indian Space Research Organisation launched its first mission to Mars with the Mars Orbiter Mission that successfully reached Mars orbit on 23 September 2014. Numerous significant milestones in robotic spaceflight occurred in 2013, including the landing of China's Chang'e 3 lander at Moon's Mare Imbrium on 14 December; it is China's first attempt and first successful soft landing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USA-235
USA-235, also known as Advanced Extremely High Frequency 2 or AEHF-2, is a military communications satellite operated by the United States Air Force. It is the second of six satellite to be launched as part of the Advanced Extremely High Frequency program, which replaced the earlier Milstar system. Satellite description The USA-235 satellite was constructed by Lockheed Martin Space, and is based on the A2100 satellite bus. The satellite has a mass of and a design life of 14 years. It will be used to provide super high frequency (SHF) and extremely high frequency (EHF) communications for the United States Armed Forces, as well as those of the United Kingdom, the Netherlands, and Canada. Launch USA-235 was launched by United Launch Alliance, aboard an Atlas V 531 flying from Space Launch Complex 41 (SLC-41) at the Cape Canaveral Air Force Station (CCAFS). The launch occurred at 18:24 UTC on 4 May 2012, first placing the satellite in a parking orbit of 185 kilometers by 90 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USA-288
USA-288, also known as Advanced Extremely High Frequency 4 or AEHF-4, is a military communications satellite operated by the United States Air Force. It is the fourth of six satellite to be launched as part of the Advanced Extremely High Frequency program, which replaced the earlier Milstar system. Satellite description The USA-288 satellite was constructed by Lockheed Martin Space, and is based on the A2100 satellite bus. The satellite has a mass of and a design life of 14 years. It will be used to provide super high frequency (SHF) and extremely high frequency (EHF) communications for the United States Armed Forces, as well as those of the United Kingdom, the Netherlands, and Canada. Launch USA-288 was launched by United Launch Alliance, aboard an Atlas V 551 flying from SLC-41 at the Cape Canaveral Air Force Station (CCAFS). The launch occurred at 04:15 UTC on 17 October 2018, placing the satellite in a parking orbit of 176 kilometers by 485 kilometers. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinated Universal Time
Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about one second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). The coordination of time and frequency transmissions around the world began on 1 January 1960. UTC was first officially adopted as CCIR Recommendation 374, ''Standard-Frequency and Time-Signal Emissions'', in 1963, but the official abbreviation of UTC and the official English name of Coordinated Universal Time (along with the French equivalent) were not adopted until 1967. The system has been adjusted several times, including a brief period during which the time-coordination radio signals broadcast both UTC and "Stepped Atomic Time (SAT)" before a new UTC was adopted in 1970 and implemented in 1972. This change also a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super High Frequency
Super high frequency (SHF) is the ITU designation for radio frequencies (RF) in the range between 3 and 30 gigahertz (GHz). This band of frequencies is also known as the centimetre band or centimetre wave as the wavelengths range from one to ten centimetres. These frequencies fall within the microwave band, so radio waves with these frequencies are called microwaves. The small wavelength of microwaves allows them to be directed in narrow beams by aperture antennas such as parabolic dishes and horn antennas, so they are used for point-to-point communication and data links This article from the beginning of the microwave era predicted the future value of microwaves for point-to-point communication. and for radar. This frequency range is used for most radar transmitters, wireless LANs, satellite communication, microwave radio relay links, satellite phones (S band), and numerous short range terrestrial data links. They are also used for heating in industrial microwave heatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in order of precedence. The United States Air Force articulates its core missions as air supremacy, global integrated intelligence, surveillance and reconnaissance, rapid global mobility, global strike, and command and control. The United States Air Force is a military service branch organized within the Department of the Air Force, one of the three military departments of the Department of Defense. The Air Force through the Department of the Air Force is headed by the civilian Secretary of the Air Force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Space Force
The United States Space Force (USSF) is the space service branch of the U.S. Armed Forces, one of the eight U.S. uniformed services, and the world's only independent space force. Along with its sister branch, the U.S. Air Force, the Space Force is part of the Department of the Air Force, one of the three civilian-led military departments within the Department of Defense. The Space Force, through the Department of the Air Force, is overseen by the secretary of the Air Force, a civilian political appointee who reports to the secretary of defense, and is appointed by the president with Senate confirmation. The military head of the Space Force is the chief of space operations who is typically the most senior Space Force officer. The chief of space operations exercises supervision over the Space Force's units and serves as one of the Joint Chiefs of Staff. The Space Force is the smallest U.S. armed service, consisting of 8,400 military personnel. The Space Force operates 77 sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. 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, compared to the larger mass, the smaller mass is negligible (e.g., f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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