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MUBLCOM
The Multiple Paths, Beyond-Line-of-Sight Communications (MUBLCOM) satellite (COSPAR 1999-026B, SATCAT 25736), built for the Pentagon's Defense Advanced Research Projects Agency, was launched in May 1999 by a Pegasus Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as hor .... Its mission was to demonstrate a capability to provide space-based digital voice and data communications to combat forces or commercial users that were previously considered out of range of standard radio communications systems. On April 15, 2005, the Demonstration of Autonomous Rendezvous Technology (DART) spacecraft collided with the MUBLCOM satellite while attempting to rendezvous with it. References * http://www.nasa.gov/pdf/148072main_DART_mishap_overview.pdf * http://science.ksc.nasa.gov/payload/missions/terrier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DART (satellite)
DART, or Demonstration for Autonomous Rendezvous Technology, was a NASA spacecraft with the goal to develop and demonstrate an automated navigation and rendezvous capability. At the time of the DART mission, only the Roscosmos and JAXA had autonomous spacecraft navigation. Orbital Sciences Corporation (OSC) was the prime contractor for construction, launch and operation of the DART spacecraft with a project cost of US$110 million (2005). The contract was awarded in June 2001 and the spacecraft was launched on 15 April 2005. The mission ended prematurely, very shortly after an anomalous slow-velocity collision with its target spacecraft, having completed less than half of the original mission autonomous rendezvous objectives. Mission DART was launched on a Pegasus rocket into a polar orbit of and has International Designator 2005-014A. The craft is and weighs . The maneuvering system comprised 16 nitrogen-fueled thrusters with three hydrazine-fueled thrusters and a reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus (rocket)
Pegasus is an air-launched launch vehicle developed by Orbital Sciences Corporation (OSC) and now built and launched by Northrop Grumman. Capable of carrying small payloads of up to into low Earth orbit, Pegasus first flew in 1990 and remains active . The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage. Pegasus is released from its carrier aircraft at approximately , and its first stage has a wing and a tail to provide lift and attitude control while in the atmosphere. Notably, the first stage does not have a thrust vector control (TVC) system. History Pegasus was designed by a team led by Antonio Elias. The Pegasus's three Orion solid motors were developed by Hercules Aerospace (later Alliant Techsystems) specifically for the Pegasus launcher but using advanced carbon fiber, propellant formulation and case insulation technologies originally developed for the terminated USAF Small ICBM program. The wing and fins' structures w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus (rocket)
Pegasus is an air-launched launch vehicle developed by Orbital Sciences Corporation (OSC) and now built and launched by Northrop Grumman. Capable of carrying small payloads of up to into low Earth orbit, Pegasus first flew in 1990 and remains active . The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage. Pegasus is released from its carrier aircraft at approximately , and its first stage has a wing and a tail to provide lift and attitude control while in the atmosphere. Notably, the first stage does not have a thrust vector control (TVC) system. History Pegasus was designed by a team led by Antonio Elias. The Pegasus's three Orion solid motors were developed by Hercules Aerospace (later Alliant Techsystems) specifically for the Pegasus launcher but using advanced carbon fiber, propellant formulation and case insulation technologies originally developed for the terminated USAF Small ICBM program. The wing and fins' structures w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DART (spacecraft)
Double Asteroid Redirection Test (DART) is a NASA space mission aimed at testing a method of planetary defense against near-Earth objects (NEOs). It was designed to assess how much a spacecraft impact deflects an asteroid through its transfer of momentum when hitting the asteroid head-on. The asteroid selected for the test poses no actual threat to Earth and was selected for the convenience of the test. The probe was launched from Earth on 24 November 2021, and on 26 September 2022 intentionally crashed into Dimorphos, the minor-planet moon of the asteroid Didymos. On 11 October, NASA declared DART a success, confirming it had shortened Dimorphos' orbital period around Didymos by about 32 minutes, surpassing the pre-defined success threshold of 73 seconds. DART is a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL). The project was funded through NASA's Planetary Defense Coordination Office, managed by NASA's Planetary Missions Program Offi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DARPA
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Advanced Research Projects Agency (ARPA), the agency was created on February 7, 1958, by President Dwight D. Eisenhower in response to the Soviet Union, Soviet launching of Sputnik 1 in 1957. By collaborating with academia, industry, and government partners, DARPA formulates and executes research and development projects to expand the frontiers of technology and science, often beyond immediate U.S. military requirements.Dwight D. Eisenhower and Science & Technology, (2008). Dwight D. Eisenhower Memorial CommissionSource ''The Economist'' has called DARPA the agency "that shaped the modern world," and pointed out that "Moderna COVID-19 vaccine, Moderna's COVID-19 vaccine sits alongside weather satellites, Global Positioning System, GPS, Unmann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vandenberg Air Force Base
Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USS General Harry Taylor (AP-145), USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida * Vandenberg Space Force Base, a United States military installation with a spaceport * Vandenberg (band), a Dutch hard rock band ** Vandenberg (album), ''Vandenberg'' (album), their 1982 debut album * Vandenberg resolution, a United States Congress resolution passed in 1948 {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Sciences
Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other government customers. In 2014, Orbital merged with Alliant Techsystems to create a new company called Orbital ATK, Inc., which in turn was purchased by Northrop Grumman in 2018. The remnants of the former Orbital Sciences Corporation today are a subsidiary of Northrop Grumman, known as Northrop Grumman Innovation Systems. Orbital was headquartered in Dulles, Virginia and publicly traded on the New York Stock Exchange with the ticker symbol ORB. Orbital's primary products were satellites and launch vehicles, including low Earth orbit (LEO), geosynchronous Earth orbit and planetary spacecraft for communications, remote sensing, scientific and defense missions; ground- and air-launched launch vehicles that delivered satellites into orbit; missile d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geocentric Orbit
A geocentric orbit or Earth orbit involves any object orbiting Earth, such as the Moon or artificial satellites. In 1997, NASA estimated there were approximately 2,465 artificial satellite payloads orbiting Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. More than 16,291 objects previously launched have undergone orbital decay and entered Earth's atmosphere. A spacecraft enters orbit when its centripetal acceleration due to gravity is less than or equal to the centrifugal acceleration due to the horizontal component of its velocity. For a low Earth orbit, this velocity is about ; by contrast, the fastest crewed airplane speed ever achieved (excluding speeds achieved by deorbiting spacecraft) was in 1967 by the North American X-15. The energy required to reach Earth orbital velocity at an altitude of is about 36 MJ/kg, which is six times the energy needed merely to climb to the corresponding altitude. Spacecraft with a perigee belo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. The term ''LEO region'' is also used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. All crewed space stations to date have been within LEO. From 1968 to 1972, the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, no human spaceflights have been beyond LEO. Defining characteristics A wide variety of sources define LEO in terms of altitude. The altitude of an object in an elliptic orbit can vary significantly along the orbit. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Pentagon
The Pentagon is the headquarters building of the United States Department of Defense. It was constructed on an accelerated schedule during World War II. As a symbol of the U.S. military, the phrase ''The Pentagon'' is often used as a metonym for the Department of Defense and its leadership. Located in Arlington County, Virginia, across the Potomac River from Washington, D.C., the building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on 11 September 1941, and the building was dedicated on 15 January 1943. General Brehon Somervell provided the major impetus to gain Congressional approval for the project; Colonel Leslie Groves was responsible for overseeing the project for the U.S. Army Corps of Engineers, which supervised it. The Pentagon is the world's largest office building, with about of floor space, of which are used as offices. Some 23,000 military and civilian employees, and another 3,000 non-defense sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Advanced Research Projects Agency (ARPA), the agency was created on February 7, 1958, by President Dwight D. Eisenhower in response to the Soviet Union, Soviet launching of Sputnik 1 in 1957. By collaborating with academia, industry, and government partners, DARPA formulates and executes research and development projects to expand the frontiers of technology and science, often beyond immediate U.S. military requirements.Dwight D. Eisenhower and Science & Technology, (2008). Dwight D. Eisenhower Memorial CommissionSource ''The Economist'' has called DARPA the agency "that shaped the modern world," and pointed out that "Moderna COVID-19 vaccine, Moderna's COVID-19 vaccine sits alongside weather satellites, Global Positioning System, GPS, Unmann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellites
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Radio receiver, 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 propagation, line of sight and so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
