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Ranger 3
Ranger 3 was a space exploration mission conducted by NASA to study the Moon. The Ranger 3 robotic spacecraft was launched January 26, 1962 as part of the Ranger program. Due to a series of malfunctions, the spacecraft missed the Moon by and entered a heliocentric orbit. The Ranger 3 space probe was designed to transmit pictures of the lunar surface during a period of 10 minutes of flight prior to impacting on the Moon, to rough-land a seismometer capsule on the Moon, to collect gamma-ray data in flight, to study radar reflectivity of the lunar surface, and to continue testing of the Ranger program for development of lunar and interplanetary spacecraft. Spacecraft design Ranger 3 was the first of the Block II Ranger designs. The basic vehicle was 3.1 m high and consisted of a lunar capsule covered with a balsa wood impact-limiter, 650 mm in diameter, a mono-propellant mid-course motor, a retrorocket with a thrust of 5080 pounds force (22.6 kN), and a gold- and c ... [...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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robotic Spacecraft
A robotic spacecraft is an uncrewed spacecraft, usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and lower risk factors. In addition, some planetary destinations such as Venus or the vicinity of Jupiter are too hostile for human survival, given current technology. Outer planets such as Saturn, Uranus, and Neptune are too distant to reach with current crewed spacecraft technology, so telerobotic probes are the only way to explore them. Nearly all satellites, landers and rovers are robotic spacecraft. History The first robotic spacecraft was launched by the Soviet Union (USSR) on 22 July 1951, a suborbital flight carrying two dogs Dezik and Tsygan. Four other such flights were made through the fall of 1951. The first artificial satellite, Sputnik 1, was put into a Earth orbit by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turnstile Antenna
A turnstile antenna, or crossed-dipole antenna, is a radio antenna consisting of a set of two identical dipole antennas mounted at right angles to each other and fed in phase quadrature; the two currents applied to the dipoles are 90° out of phase. filed: September 20, 1935; granted: July 13, 1937 The name reflects the notion the antenna looks like a turnstile when mounted horizontally. The antenna can be used in two possible modes. In ''normal mode'' the antenna radiates horizontally polarized radio waves perpendicular to its axis. In ''axial mode'' the antenna radiates circularly polarized radiation along its axis. Specialized normal mode turnstile antennas called ''superturnstile'' or '' batwing antennas'' are used as television broadcasting antennas. Axial mode turnstiles are widely used for satellite ground station antennas in the VHF and UHF bands, as circular polarization is often used for satellite communication since it is not sensitive to the orientation of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Altimeter
A radar altimeter (RA), also called a radio altimeter (RALT), electronic altimeter, reflection altimeter, or low-range radio altimeter (LRRA), measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it takes a beam of radio waves to travel to ground, reflect, and return to the craft. This type of altimeter provides the distance between the antenna and the ground directly below it, in contrast to a barometric altimeter which provides the distance above a defined vertical datum, usually mean sea level. Principle As the name implies, radar (radio detection and ranging) is the underpinning principle of the system. The system transmits radio waves down to the ground and measures the time it takes them to be reflected back up to the aircraft. The altitude above the ground is calculated from the radio waves' travel time and the speed of light. Radar altimeters required a simple system for measuring the time-of-flight that could be displaye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vidicon
Video camera tubes were devices based on the cathode ray tube that were used in television cameras to capture television images, prior to the introduction of charge-coupled device (CCD) image sensors in the 1980s. Several different types of tubes were in use from the early 1930s, and as late as the 1990s. In these tubes, an cathode ray, electron beam was scanned across an image of the scene to be broadcast focused on a target. This generated a current that was dependent on the brightness of the image on the target at the scan point. The size of the striking ray was tiny compared to the size of the target, allowing 483 horizontal scan lines per image in the NTSC format, 576 lines in PAL, and as many as 1035 lines in Multiple sub-Nyquist sampling encoding, Hi-Vision. Cathode ray tube Any vacuum tube which operates using a focused beam of electrons, originally called cathode rays, is known as a cathode ray tube (CRT). These are usually seen as display devices as used in older (i.e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block II
Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 the Block '' * WFNZ-FM, a radio station licensed to Harrisburg, North Carolina, United States, branded as ''92.7 The Block'' * Blocked (''The Flash''), an episode of the television series ''The Flash'' Music * Block Entertainment, a record label * Blocks Recording Club, a record label * Woodblock (instrument), a small piece of slit drum made from one piece of wood and used as a percussion instrument * "Blocks", by C418 from '' Minecraft - Volume Beta'', 2013 Toys * Toy block, one of a set of wooden or plastic pieces, of various shapes * Unit block, a type of standardized wooden toy block for children Video game * Blocked (video game), a puzzle game for the iPhone and iPod Touch Building and construction * Breeze block, cinder block ... [...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] |
Telemetry
Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the 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 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 display, recording, or control device. Electronic devices are widely used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscope
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in gyrotheodolites to maintain direction in tunnel mining. Gyrosco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balsa Wood
''Ochroma pyramidale'', commonly known as the balsa tree, is a large, fast-growing tree native to the Americas. It is the sole member of the genus ''Ochroma''. The tree is famous for its wide usage in woodworking, with the name ''balsa'' being the Spanish word for "raft." A deciduous angiosperm, ''Ochroma pyramidale'' can grow up to 30 m tall, and is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood and is widely used because of its light weight. Biology Balsa on Limbe_Botanical_Garden.html" ;"title="Bota Hill, Limbe Botanical Garden">Bota Hill, Limbe Botanical Garden, Cameroon A member of the mallow family, ''Ochroma pyramidale'' is native from southern Mexico to southern Brazil, but can now be found in many other countries (Papua New Guinea, Indonesia, Thailand, Solomon Islands). It is a pioneer plant, which establishes itself in clearings in forests, either man-made or where trees have fallen, or in abandoned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranger 3-4-5 Probe
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 (Middle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma-ray
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz (), it imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation ''gamma rays'' based on their relatively strong penetration of matter; in 1900 he had already named two less penetrating types of decay radiation (discovered by Henri Becquerel) alpha rays and beta rays in ascending order of penetrating power. Gamma rays from radioactive decay are in the energy range from a few kiloelectronvolts (keV) to approximately 8 megaelectronvolts (MeV), corresponding to the typical energy levels in nuclei with reasonably long lifetimes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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