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Uncrewed NASA Missions
Since 1958, NASA has overseen more than 1,000 Uncrewed spacecraft, uncrewed missions into Earth orbit or beyond. It has both launched its own missions and provided funding for private-sector missions. A number of NASA missions, including the #Explorers Program (1958–present), Explorers Program, #Voyager program (1977–present), Voyager program, and #New Frontiers program (2006–present), New Frontiers program, are ongoing. List of missions Explorers Program (1958–present) The Explorer program has launched more than 90 missions since it began more than five decades ago. It has matured into one of NASA's lower-cost mission programs. The program started as a U.S. Army proposal to place a scientific satellite into orbit during the International Geophysical Year (1957–58). However, that proposal was rejected in favor of the U.S. Navy's Project Vanguard. The Explorer program was later reestablished to catch up with the Soviet Union after the launch of ''Sputnik 1'' in Octo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer 11
''Pioneer 11'' (also known as ''Pioneer G'') is a robotic space probe launched by NASA on April 5, 1973, to study the asteroid belt, the environment around Jupiter and Saturn, solar winds, and cosmic rays. It was the first probe to encounter Saturn, the second to fly through the asteroid belt, and the second to fly by Jupiter. Later, ''Pioneer 11'' became the second of five artificial objects to achieve an escape velocity allowing it to leave the Solar System. Due to power constraints and the vast distance to the probe, the last routine contact with the spacecraft was on September 30, 1995, and the last good engineering data was received on November 24, 1995. Mission background History Approved in February 1969, ''Pioneer 11'' and its twin probe, ''Pioneer 10'', were the first to be designed for exploring the outer Solar System. Yielding to multiple proposals throughout the 1960s, early mission objectives were defined as: * Explore the interplanetary medium beyond the orbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Rocket
Delta is an American versatile family of expendable launch systems that has provided space launch capability in the United States since 1960. Japan also launched license-built derivatives (N-I, N-II, and H-I) from 1975 to 1992. More than 300 Delta rockets have been launched with a 95% success rate. Only the Delta IV Heavy rocket remains in use as of November 2020. Delta rockets have stopped being manufactured in favor of Vulcan. Origins The original Delta rockets used a modified version of the PGM-17 Thor, the first ballistic missile deployed by the United States Air Force (USAF), as their first stage. The Thor had been designed in the mid-1950s to reach Moscow from bases in Britain or similar allied nations, and the first wholly successful Thor launch had occurred in September 1957. Subsequent satellite and space probe flights soon followed, using a Thor first stage with several different upper stages. The fourth upper stage used on the Thor was the Thor "Delta", delt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northfield, Minnesota
Northfield is a city in Dakota and Rice counties in the State of Minnesota. It is mostly in Rice County, with a small portion in Dakota County. The population was 20,790 at the 2020 census. History Northfield was platted in 1856 by John W. North. Local legend says that the town was named for John North and a Mr. Field. North, realizing that the town straddled the proposed northern border of Rice county, went to the state capital to lobby to move the border one mile north. Northfield was founded by settlers from New England known as "Yankees" as part of New England's colonization of what was then the far west. It was an early agricultural center with many wheat and corn farms. The town also supported lumber and flour mills powered by the Cannon River. As the "wheat frontier" moved west, dairy operations and diversified farms replaced wheat-based agriculture. The region has since moved away from dairy and beef operations. Today it produces substantial crops of corn and soybeans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilmore Schjeldahl
Gilmore Tilmen Schjeldahl (June 1, 1912March 10, 2002) was an American businessman and inventor in plastics, adhesives and circuitry. He was awarded 16 US patents and may be best known for inventing the plastic-lined airsickness bag. Biography Early life and education Gilmore Tilmen Schjeldahl was born in Esmond, North Dakota to Norwegian immigrants. His father was a railroad worker. He grew up in Northwood, North Dakota and did not graduate from high school, but took courses at North Dakota State College of Science and North Dakota State University before being drafted into the U.S. Army to serve during World War II. Schjeldahl served in three battles with the 84th Division, including the Battle of the Bulge, in which his actions were awarded with a Bronze Star. Career Schjeldahl began his career at Armour and Company, where he began working with polyethylene. Unable to get the material to seal to itself, he and his wife experimented on solutions at home, where they developed a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mission And Spacecraft Library
Mission and Spacecraft Library (MSL) is a reference web site, maintained by NASA, containing information about satellites. It contains a catalog of several hundreds of satellites from different countries. The site was founded by Jet Propulsion Laboratory employee Mike Evans, who had a vision of building a database that would be publicly accessible via the World Wide Web The World Wide Web (WWW), commonly known as the Web, is an information system enabling documents and other web resources to be accessed over the Internet. Documents and downloadable media are made available to the network through web .... The site has not been updated since 1999. External links Mission and Spacecraft Library American educational websites Online databases Government databases in the United States NASA online Spaceflight {{space-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ranges as microwaves; the above broad definition includes both UHF and EHF (millimeter wave) bands. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 0.3 m and 3 mm). In all cases, microwaves include the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band, or by similar NATO or EU designations. The prefix ' in ''microwave'' is not meant to suggest a wavelength in the micrometer range. Rather, it indicates that microwaves are "small" (having shorter wavelengths), compared to the radio waves used prior to microwave te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The ''law of reflection'' says that for specular reflection (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflection of Very high frequency, VHF and higher frequencies is important for radio transmission and for radar. Even hard X-rays and gamma rays can be reflected at shallow angles with special "grazing" mirrors. Reflection of light Reflection of light is either ''Specular reflection, specular'' (mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balloon Satellite
A balloon satellite is inflated with gas after it has been put into orbit. It is also occasionally referred to as a "satelloon", which is a trademarked name owned by Gilmore Schjeldahl's G.T. Schjeldahl Company. List of balloon satellites abbreviations: * pcr = passive communications reflector, satellite reflects microwave signals. * ado = atmospheric density observations * spc = solar pressure calculations, estimate impact of solar wind on orbit. * tri = satellite triangulation, measuring the Earth's surface. * SC = Sensors and camera for earth curvature images Echo 1 and Echo 2 balloon satellites The first flying body of this type was Echo 1, which was launched into a high orbit on August 12, 1960, by the United States. It originally had a spherical shape measuring , with a thin metal-coated plastic shell made of Mylar. It served for testing as a "passive" communication and geodetic satellite. Its international COSPAR number was 6000901 (9th satellite launched in 1960, 1s ... [...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] |
Echo II
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Echo II or Echo 2 or ''variant'', may refer to: * ''Echo II''-class submarine of the Soviet Navy * Echo 2 (satellite), a 1964 NASA communications satellite * Echo II (expansion card), a speech synthesizer card for the Apple II See also * EchoStar II, a 1990s communications satellite * Echo (other) An echo is a reflection of sound. Echo may also refer to: Mythology * Echo (mythology), a nymph in Greek mythology, for whom the sound reflection phenomenon was named. Arts, entertainment, and media Fictional entities * Echo (DC Comics), vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer Venus Project
The Pioneer Venus project was part of the Pioneer program consisting of two spacecraft, the Pioneer Venus Orbiter and the Pioneer Venus Multiprobe, launched to Venus in 1978. The program was managed by NASA's Ames Research Center. The Pioneer Venus Orbiter entered orbit around Venus on December 4, 1978, and performed observations to characterize the atmosphere and surface of Venus. It continued to transmit data until October 1992. The Pioneer Venus Multiprobe deployed four small probes into the Venusian atmosphere on December 9, 1978. All four probes transmitted data throughout their descent to the surface. One probe survived the landing and transmitted data from the surface for over an hour. Overview The Pioneer mission consisted of two components, launched separately: an orbiter and a multiprobe. Orbiter The orbiter was launched on May 20, 1978 on an Atlas-Centaur rocket. The orbiter's mass was . The Pioneer Venus Orbiter was inserted into an elliptical orbit around V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
