Microgravity
The term micro-g environment (also μg, often referred to by the term microgravity) is more or less synonymous with the terms '' weightlessness'' and ''zero-g'', but emphasising that g-forces are never exactly zero—just very small (on the International Space Station (ISS), for example, the small g-forces come from tidal effects, gravity from objects other than the Earth, such as astronauts, the spacecraft, and the Sun, air resistance, and astronaut movements that impart momentum to the space station). The symbol for microgravity, ''μg'', was used on the insignias of Space Shuttle flights STS-87 and STS-107, because these flights were devoted to microgravity research in low Earth orbit. The most commonly known microgravity environment can be found aboard the ISS which is located in low-earth orbit at an altitude of around 400 km, orbiting Earth approximately 15 times per day in what is considered free fall. The effects of free fall also enable the creation of sh ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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International Space Station
The International Space Station (ISS) is the largest Modular design, modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA (Japan), European Space Agency, ESA (Europe), and Canadian Space Agency, CSA (Canada). The ownership and use of the space station is established by intergovernmental treaties and agreements. The station serves as a microgravity and space environment research laboratory in which Scientific research on the International Space Station, scientific research is conducted in astrobiology, astronomy, meteorology, physics, and other fields. The ISS is suited for testing the spacecraft systems and equipment required for possible future long-duration missions to the Moon and Mars. The International Space Station programme, ISS programme evolved from the Space Station Freedom, Space Station ''Freedom'', a 1984 American proposal to constr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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STS-87
STS-87 was a Space Shuttle mission launched from Launch Complex 39B of the Kennedy Space Center on 19 November 1997. It was the 88th flight of the Space Shuttle and the 24th flight of ''Columbia''. The mission goals were to conduct experiments using the United States Microgravity Payload (USMP-4), conduct two EVAs, and deploy the SPARTAN-201 experiment. This mission marked the first time an EVA was performed from ''Columbia''. An EVA from ''Columbia'' was originally planned for STS-5 in 1982 but was canceled due to spacesuit problems. It also marked the first EVA conducted by a Japanese astronaut, Takao Doi. Crew Backup crew Space walks *'' Scott and Doi'' – EVA 1 *EVA 1 Start: 25 November 1997 – 00:02 UTC *EVA 1 End: 25 November 1997 – 07:45 UTC *Duration: 7 hours, 43 minutes *'' Scott and Doi'' – EVA 2 *EVA 2 Start: 3 December 1997 – 09:09 UTC *EVA 2 End: 3 December 1997 – 14:09 UTC *Duration: 4 hours, 59 minutes Mission highlights STS-87 flew the United Sta ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Weightlessness
Weightlessness is the complete or near-complete absence of the sensation of weight. It is also termed zero gravity, zero G-force, or zero-G. Weight is a measurement of the force on an object at rest in a relatively strong gravitational field (such as on the surface of the Earth). These weight-sensations originate from contact with supporting floors, seats, beds, scales, and the like. A sensation of weight is also produced, even when the gravitational field is zero, when contact forces act upon and overcome a body's inertia by mechanical, non- gravitational forces- such as in a centrifuge, a rotating space station, or within an accelerating vehicle. When the gravitational field is non-uniform, a body in free fall experiences tidal effects and is not stress-free. Near a black hole, such tidal effects can be very strong. In the case of the Earth, the effects are minor, especially on objects of relatively small dimensions (such as the human body or a spacecraft) and the overa ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Drop Tube
In physics and materials science, a drop tower or drop tube is a structure used to produce a controlled period of weightlessness for an object under study. Air bags, polystyrene pellets, and magnetic or mechanical brakes are sometimes used to arrest the fall of the experimental payload. In other cases, high-speed impact with a substrate at the bottom of the tower is an intentional part of the experimental protocol. Not all such facilities are towers: NASA Glenn's Zero Gravity Research Facility is based on a vertical shaft, extending to below ground level. Typical operation For a typical materials science experiment, a sample of the material under study is loaded into the top of the drop tube, which is filled with inert gas or evacuated to create a low-pressure environment. Following any desired preprocessing (e.g. induction heating to melt a metal alloy), the sample is released to fall to the bottom of the tube. During its flight or upon impact the sample can be c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Random Positioning Machine
A random positioning machine, or RPM, rotates biological samples along two independent axes to change their orientation in space in complex ways and so eliminate the effect of gravity.Jack J.W.A. van Loon (2007). Some history and use of the random positioning machine, RPM, in gravity related research. Advances in Space Research 39: 1161-1165 Description The RPM is a more sophisticated development of the single-axis clinostat. RPMs usually consist of two independently rotating frames. One frame is positioned inside the other giving a very complex net change of orientation to a biological sample mounted in the middle. The RPM is sometimes wrongly referred to as the "3-D clinostat" (which rotates both axis in the same direction, i.e. both clockwise). It is a microweight ('micro-gravity') simulator that is based on the principle of 'gravity-vector-averaging'. RPM provides a functional volume which is 'exposed' to simulated microweight.A. G. Borst, J.J.W. A. van Loon. Technology and D ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Reduced-gravity Aircraft
A reduced-gravity aircraft is a type of fixed-wing aircraft that provides brief near-weightless environments for training astronauts, conducting research and making gravity-free movie shots. Versions of such airplanes were operated by the NASA Reduced Gravity Research Program, and one is currently operated by the Human Spaceflight and Robotic Exploration Programmes of the European Space Agency. The unofficial nickname "vomit comet" became popular among those who experienced their operation. History Parabolic flight as a way of simulating weightlessness was first proposed by the German aerospace engineer Fritz Haber and the German physicist Heinz Haber in 1950. Both had been brought to the US after World War II as part of Operation Paperclip. As well, Shih-Chun Wang studied nausea in astronauts for NASA, which helped lead to the creation of the vomit comet. Parabolic flights are sometimes used to examine the effects of weightlessness on a living organism. While humans are ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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STS-107
STS-107 was the 113th flight of the Space Shuttle program, and the 28th and final flight of Space Shuttle ''Columbia''. The mission launched from Kennedy Space Center in Florida on January 16, 2003, and during its 15 days, 22 hours, 20 minutes, 32 seconds in orbit conducted a multitude of international scientific experiments. It was also the 88th post-Challenger disaster mission. An in-flight break up during reentry into the atmosphere on February 1 killed all seven crew members and disintegrated ''Columbia''. Immediately after the disaster, NASA convened the ''Columbia'' accident Investigation Board to determine the cause of the disintegration. The source of the failure was determined to have been caused by a piece of foam that broke off during launch and damaged the thermal protection system ( reinforced carbon-carbon panels and thermal protection tiles) on the leading edge of the orbiter's left wing. During re-entry the damaged wing slowly overheated and came apart, event ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Attenuation
In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates. Hearing protectors help reduce acoustic flux from flowing into the ears. This phenomenon is called acoustic attenuation and is measured in decibels (dBs). In electrical engineering and telecommunications, attenuation affects the propagation of waves and signals in electrical circuits, in optical fibers, and in air. Electrical attenuators and optical attenuators are commonly manufactured components in this field. Background In many cases, attenuation is an exponential function of the path length through the medium. In optics and in chemical spectroscopy, this is known as the Beer–Lambert law. In engineering, attenuation is usually measured in units of decibels per unit length of medium (dB/cm, dB/km, etc.) ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Interstellar Probe
An interstellar probe is a space probe that has left—or is expected to leave—the Solar System and enter interstellar space, which is typically defined as the region beyond the heliopause. It also refers to probes capable of reaching other star systems. There are five interstellar probes, all launched by the American space agency NASA: ''Voyager 1'', ''Voyager 2'', ''Pioneer 10'', '' Pioneer 11'' and ''New Horizons''. As of 2019, ''Voyager 1'', ''Voyager 2'' and ''Pioneer 10'' are the only probes to have actually reached interstellar space. The other two are on interstellar trajectories. The termination shock is the point in the heliosphere where the solar wind slows down to subsonic speed. Even though the termination shock happens as close as 80–100 AU (astronomical units) the maximum extent of the region in which the Sun's gravitational field is dominant (the Hill sphere) is thought to be at around . This point is close to the nearest known star system, Alpha Centaur ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Voyager 1
''Voyager 1'' is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and interstellar space beyond the Sun's heliosphere. Launched 16 days after its twin '' Voyager 2'', ''Voyager 1'' has been operating for as of . It communicates through NASA's Deep Space Network to receive routine commands and to transmit data to Earth. Real-time distance and velocity data is provided by NASA and JPL. At a distance of from Earth , it is the most distant human-made object from Earth. The probe made flybys of Jupiter, Saturn, and Saturn's largest moon, Titan. NASA had a choice of either doing a Pluto or Titan flyby; exploration of the moon took priority because it was known to have a substantial atmosphere. ''Voyager 1'' studied the weather, magnetic fields, and rings of the two gas giants and was the first probe to provide detailed images of their moons. As part of the Voyager program and like its sister craft '' Voyager ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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MG (other)
MG, Mg, or mg and variants may refer to: Organizations * MG Cars, an automotive marque of the now defunct MG Car Company * MG Motor, a present-day car manufacturing company *MG JW Automobile, a Pakistani automobile manufacturer * Champion Air (IATA code) * Matematička gimnazija, a school in Belgrade * Monte Generoso railway Arts and entertainment * MG, a character in ''The Perhapanauts'' comics * ''Match Game'', a television game show * Magilla Gorilla, a cartoon character Music * ''Main gauche'', "left hand" in piano playing * ''MG'' (Martin Gore album) * The M.G.'s, from the band Booker T. & the M.G.'s * ''The MG's'' (album), an album by the M.G.'s * MG Select, a house duo music production including George Jackson * M:G, real name Maribel Gonzalez, dance music singer Military * Machine gun (MG-), prefix for model designations, for example, "MG42" * Major general, a military rank * Medal for Gallantry, a military decoration Places * Madagascar (ISO 3166-1 country code ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Voyager 2
''Voyager 2'' is a space probe launched by NASA on August 20, 1977, to study the outer planets and interstellar space beyond the Sun's heliosphere. As a part of the Voyager program, it was launched 16 days before its twin, ''Voyager 1'', on a trajectory that took longer to reach gas giants Jupiter and Saturn but enabled further encounters with ice giants Uranus and Neptune. ''Voyager 2'' remains the only spacecraft to have visited either of the ice giant planets. ''Voyager 2'' was the fourth of five spacecraft to achieve Solar escape velocity, which allowed it to leave the Solar System. ''Voyager 2'' successfully fulfilled its primary mission of visiting the Jovian system in 1979, the Saturnian system in 1981, Uranian system in 1986, and the Neptunian system in 1989. The spacecraft is now in its extended mission of studying interstellar space. It has been operating for as of ; , it has reached a distance of from Earth. The probe entered interstellar space on Nov ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |