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Night Glider Mode
Night Glider mode (or "XVV Night Glider mode") is one of the procedures for orienting the solar arrays on the International Space Station. Normally the photovoltaic solar arrays of the space station track the sun. However, one of the main causes of orbital decay on the space station is that the area of the solar arrays, brushing against the thin residual atmosphere at orbital altitude, results in a small amount of aerodynamic drag. The drag can be lowered by orienting the solar arrays in "sun slicer" mode, where they fly edge-on to the orbital direction, rather than tracking the sun, however, this orientation reduces the power produced. The "night glider" mode is a hybrid orientation,G. Landis and C-Y Lu, "Solar Array Orientation Options for a Space Station in Low Earth Orbit", ''Journal of Propulsion and Power, Vol. 7'' No. 1, 123-125 (1991). where the solar arrays track the sun during the period when the space station is illuminated, are rotated edge-on to the orbital direc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISS On 20 August 2001
The International Space Station (ISS) is the largest 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), ESA (Europe), and 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 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 ISS programme evolved from the Space Station ''Freedom'', a 1984 American proposal to construct a permanently crewed Earth-orbiting station, and the contemporaneous Soviet/Russian ''Mir-2'' proposal from 1976 with similar aims. The ISS is the ninth space station to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photovoltaic System
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct current, direct to alternating current, as well as photovoltaic mounting system, mounting, solar cable, cabling, and other electrical accessories to set up a working system. It may also use a solar tracking system to improve the system's overall performance and include an rechargeable battery, integrated battery. PV systems convert light directly into electricity, and are not to be confused with other solar technologies, such as concentrated solar power or Solar thermal energy, solar thermal, used for heating and cooling. A solar array only encompasses the ensemble of solar panels, the visible part of the PV system, and does not include all the other hardw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Space Station
The International Space Station (ISS) is the largest 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), ESA (Europe), and 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 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 ISS programme evolved from the Space Station ''Freedom'', a 1984 American proposal to construct a permanently crewed Earth-orbiting station, and the contemporaneous Soviet/Russian '' Mir-2'' proposal from 1976 with similar aims. The ISS is the ninth space station to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photovoltaics
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially used for electricity generation and as photosensors. A photovoltaic system employs solar modules, each comprising a number of solar cells, which generate electrical power. PV installations may be ground-mounted, rooftop-mounted, wall-mounted or floating. The mount may be fixed or use a solar tracker to follow the sun across the sky. Photovoltaic technology helps to mitigate climate change because it emits much less carbon dioxide than fossil fuels. Solar PV has specific advantages as an energy source: once installed, its operation generates no pollution and no greenhouse gas emissions, it shows scalability in respect of power needs and silicon has large availability in the Earth's crust, although other materials required in PV system m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Decay
Orbital decay is a gradual decrease of the distance between two orbiting bodies at their closest approach (the periapsis) over many orbital periods. These orbiting bodies can be a planet and its satellite, a star and any object orbiting it, or components of any binary system. If left unchecked, the decay eventually results in termination of the orbit when the smaller object strikes the surface of the primary; or for objects where the primary has an atmosphere, the smaller object burns, explodes, or otherwise breaks up in the larger object's atmosphere; or for objects where the primary is a star, ends with incineration by the star's radiation (such as for comets). Collisions of stellar-mass objects are usually accompanied by effects such as gamma-ray bursts and detectable gravitational waves. Orbital decay is caused by one or more mechanisms which absorb energy from the orbital motion, such as fluid friction, gravitational anomalies, or electromagnetic effects. For bodies i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamic Drag
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Shuttle Columbia Disaster
The Space Shuttle ''Columbia'' disaster was a fatal accident in the United States space program that occurred on February 1, 2003. During the STS-107 mission, Space Shuttle ''Columbia'' disintegrated as it reentered the atmosphere over Texas, killing all seven astronauts on board. The mission was the second that ended in disaster in the Space Shuttle program after the loss of ''Challenger'' and all seven crew members during ascent in 1986. During the STS-107 launch, a piece of the insulative foam broke off from the Space Shuttle external tank and struck the thermal protection system tiles on the orbiter's left wing. Similar foam shedding had occurred during previous Space Shuttle launches, causing damage that ranged from minor to near-catastrophic, but some engineers suspected that the damage to ''Columbia'' was more serious. Before reentry, NASA managers had limited the investigation, reasoning that the crew could not have fixed the problem if it had been confirmed. When ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development. The first ( STS-1) of four orbital test flights occurred in 1981, leading to operational flights (STS-5) beginning in 1982. Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. They launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST), conducted science experiments in orbit, participated in the Shuttle-''Mir'' program with Russia, and participated in construction and servicing of the International Space Station (ISS). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Shuttle Program
The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official name, Space Transportation System (STS), was taken from a 1969 plan for Space Transportation System, a system of reusable spacecraft of which it was the only item funded for development. It flew 135 missions and carried 355 astronauts from 16 countries, many on multiple trips. The Space Shuttle—composed of an Space Shuttle orbiter, orbiter launched with two reusable Space Shuttle Solid Rocket Booster, solid rocket boosters and a disposable Space Shuttle external tank, external fuel tank—carried up to eight astronauts and up to of Payload (air and space craft), payload into low Earth orbit (LEO). When its mission was complete, the orbiter would atmospheric reentry, reenter the Earth's atmosphere and land like a glider (aircr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical System Of The International Space Station
The electrical system of the International Space Station is a critical resource for the International Space Station (ISS) because it allows the crew to live comfortably, to safely operate the station, and to perform scientific experiments. The ISS electrical system uses solar cells to directly convert sunlight to electricity. Large numbers of cells are assembled in arrays to produce high power levels. This method of harnessing solar power is called photovoltaics. The process of collecting sunlight, converting it to electricity, and managing and distributing this electricity builds up excess heat that can damage spacecraft equipment. This heat must be eliminated for reliable operation of the space station in orbit. The ISS power system uses radiators to dissipate the heat away from the spacecraft. The radiators are shaded from sunlight and aligned toward the cold void of deep space. Solar array wing Each ISS solar array wing (often abbreviated "SAW") consists of two re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
