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Ranger 7
Ranger 7 was the first space probe of the United States to successfully transmit close images of the lunar surface back to Earth. It was also the first completely successful flight of the Ranger program. Launched on July 28, 1964, Ranger 7 was designed to achieve a lunar-impact trajectory and to transmit high-resolution photographs of the lunar surface during the final minutes of flight up to impact. The spacecraft carried six television vidicon cameras – two wide-angle (channel F, cameras A and B) and four narrow-angle (channel P) – to accomplish these objectives. The cameras were arranged in two separate chains, or channels, each self-contained with separate power supplies, timers, and transmitters so as to afford the greatest reliability and probability of obtaining high-quality video pictures. Ranger 7 transmitted over 4,300 photographs during the final 17 minutes of its flight. After 68.6 hours of flight, the spacecraft landed between Mare Nubium and Oceanus Procellarum. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranger 7 Cameras
A Ranger is typically someone in a military/paramilitary or law enforcement role specializing in patrolling a given territory, called “ranging”. The term most often refers to: * Park ranger or forest ranger, a person charged with protecting and preserving protected parklands and forests. ** National Park Service ranger, an employee of the National Park Service ** U.S. Forest Service ranger, an employee of the United States Forest Service ** Ranger of Windsor Great Park, a ceremonial office of the United Kingdom * Ranger (character class), a class that appears in many different role-playing games Ranger or Rangers may also refer to: Arts and entertainment Publications * Ranger's Apprentice, a series of novels by John Flanagan * ''Ranger Rick'', a children's nature magazine published by the United States National Wildlife Federation * ''Ranger'' (magazine), a former British comic magazine Fictional entities * Rangers (comics), a Marvel Comics superhero team * Ranger (Midd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Bratenahl
Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Aleksander and Aleksandr. Related names and diminutives include Iskandar, Alec, Alek, Alex, Alexandre, Aleks, Aleksa and Sander; feminine forms include Alexandra, Alexandria, and Sasha. Etymology The name ''Alexander'' originates from the (; 'defending men' or 'protector of men'). It is a compound of the verb (; 'to ward off, avert, defend') and the noun (, genitive: , ; meaning 'man'). It is an example of the widespread motif of Greek names expressing "battle-prowess", in this case the ability to withstand or push back an enemy battle line. The earliest attested form of the name, is the Mycenaean Greek feminine anthroponym , , (/ Alexandra/), written in the Linear B syllabic script. Alaksandu, alternatively called ''Alakasandu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Discharge
Electrostatic discharge (ESD) is a sudden and momentary flow of electric current between two electrically charged objects caused by contact, an short circuit, electrical short or dielectric breakdown. A buildup of static electricity can be caused by tribocharging or by electrostatic induction. The ESD occurs when differently-charged objects are brought close together or when the dielectric between them breaks down, often creating a visible electric spark, spark. ESD can create spectacular electric sparks (lightning, with the accompanying sound of thunder, is a large-scale ESD event), but also less dramatic forms which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices. Electric sparks require a field strength above approximately 40 kV/cm in air, as notably occurs in lightning strikes. Other forms of ESD include corona discharge from sharp electrodes and brush discharge from blunt electrodes. ESD can cause harmful effects of imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TV Camera
A professional video camera (often called a television camera even though its use has spread beyond television) is a high-end device for creating electronic moving images (as opposed to a movie camera, that earlier recorded the images on film). Originally developed for use in television studios or with outside broadcast trucks, they are now also used for music videos, direct-to-video movies (see digital movie camera), corporate and educational videos, wedding videos, among other uses. Since the 2000s, most professional video cameras are digital (instead of analog) professional video cameras. The distinction between professional video cameras and movie cameras became much smaller as HD digital video cameras with sensors the same size as 35mm movie cameras - plus dynamic range (exposure latitude) and color rendition approaching film quality - were introduced in the late 2010s. Nowadays, HDTV cameras designed for broadcast television, news, sports, events and other works such as rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Tension
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a test charge between the two points. In the International System of Units, the derived unit for voltage is named ''volt''. The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in generator, inductors, and transformers). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential such as the ground of the system is used as one of the points. A voltage can represent either a sour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hightstown, New Jersey
Hightstown is a borough in Mercer County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 5,494,DP-1 - Profile of General Population and Housing Characteristics: 2010 for Hightstown borough, Mercer County, New Jersey , . Accessed March 14, 2012. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranger 1
Ranger 1 was a prototype spacecraft launched as part of the Ranger program of unmanned space missions. Its primary mission was to test the performance of those functions and parts necessary for carrying out subsequent lunar and planetary missions; a secondary objective was to study the nature of particles and fields in the space environment. Due to a launch vehicle malfunction, the spacecraft could reach only Low Earth orbit, rather than the high Earth orbit that had been planned, and was only able to complete part of its mission. National Space Science Data Center, Ranger 1, NSSDC ID: 1961-021A Spacecraft design The spacecraft was of the Ranger Block I design and consisted of a hexagonal base across upon which was mounted a cone-shaped high tower of aluminum struts and braces. Two solar panel wings measuring from tip to tip extended from the base. A high-gain directional dish antenna was attached to the bottom of the base. Spacecraft experiments and other equipment were mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Congress
The United States Congress is the legislature of the federal government of the United States. It is bicameral, composed of a lower body, the House of Representatives, and an upper body, the Senate. It meets in the U.S. Capitol in Washington, D.C. Senators and representatives are chosen through direct election, though vacancies in the Senate may be filled by a governor's appointment. Congress has 535 voting members: 100 senators and 435 representatives. The U.S. vice president has a vote in the Senate only when senators are evenly divided. The House of Representatives has six non-voting members. The sitting of a Congress is for a two-year term, at present, beginning every other January. Elections are held every even-numbered year on Election Day. The members of the House of Representatives are elected for the two-year term of a Congress. The Reapportionment Act of 1929 establishes that there be 435 representatives and the Uniform Congressional Redistricting Act requires ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware River and Pennsylvania; and on the southwest by Delaware Bay and the state of Delaware. At , New Jersey is the fifth-smallest state in land area; but with close to 9.3 million residents, it ranks 11th in population and first in population density. The state capital is Trenton, and the most populous city is Newark. With the exception of Warren County, all of the state's 21 counties lie within the combined statistical areas of New York City or Philadelphia. New Jersey was first inhabited by Native Americans for at least 2,800 years, with the Lenape being the dominant group when Europeans arrived in the early 17th century. Dutch and Swedish colonists founded the first European settlements in the state. The British later seized control o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telemetry
Telemetry is the in situ data collection, collection of measurements or other data at remote points and their automatic data transmission, transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek language, Greek roots ''tele'', "remote", and ''metron'', "measure". Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand. Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or Infrared#Communications, infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers. Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data. A ''telemeter'' is a physical device used in telemetry. It consists of a sensor, a transmission path, and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Short
A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit. The opposite of a short circuit is an "open circuit", which is an infinite resistance between two nodes. Definition A short circuit is an abnormal connection between two nodes of an electric circuit intended to be at different voltages. This results in an electric current limited only by the Thévenin equivalent resistance of the rest of the network which can cause circuit damage, overheating, fire or explosion. Although usually the result of a fault, there are cases where short circuits are caused intentionally, for example, for the purpose of voltage-sensing crowbar circuit protectors. In circuit analysis, a ''short circuit'' is defined as a connection between two nodes that forces them to be at the same voltage. In an 'ideal' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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