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StarTram
StarTram is a proposed space launch system propelled by maglev. The initial Generation 1 facility would launch cargo only, launching from a mountain peak at an altitude of with an evacuated tube staying at local surface level; it has been claimed that about 150,000 tons could be lifted to orbit annually. More advanced technology would be required for the Generation 2 system for passengers, with a longer track instead gradually curving up at its end to the thinner air at altitude, supported by magnetic levitation, reducing g-forces when each capsule transitions from the vacuum tube to the atmosphere. A SPESIF 2010 presentation stated that Generation 1 could be completed by the year 2020 or later if funding began in 2010, and Generation 2 by 2030 or later. History James R. Powell invented the superconducting maglev concept in the 1960s with a colleague, Gordon Danby, also at Brookhaven National Laboratory, which was subsequently developed into modern maglev trains. Later, Pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Startram
StarTram is a proposed space launch system propelled by maglev. The initial Generation 1 facility would launch cargo only, launching from a mountain peak at an altitude of with an evacuated tube staying at local surface level; it has been claimed that about 150,000 tons could be lifted to orbit annually. More advanced technology would be required for the Generation 2 system for passengers, with a longer track instead gradually curving up at its end to the thinner air at altitude, supported by magnetic levitation, reducing g-forces when each capsule transitions from the vacuum tube to the atmosphere. A SPESIF 2010 presentation stated that Generation 1 could be completed by the year 2020 or later if funding began in 2010, and Generation 2 by 2030 or later. History James R. Powell invented the superconducting maglev concept in the 1960s with a colleague, Gordon Danby, also at Brookhaven National Laboratory, which was subsequently developed into modern maglev trains. Later, Pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Motor
A linear motor is an electric motor that has had its stator and rotor "unrolled", thus, instead of producing a torque ( rotation), it produces a linear force along its length. However, linear motors are not necessarily straight. Characteristically, a linear motor's active section has ends, whereas more conventional motors are arranged as a continuous loop. A typical mode of operation is as a Lorentz-type actuator, in which the applied force is linearly proportional to the current and the magnetic field (\vec F = I \vec L \times \vec B). Linear motors are by far most commonly found in high accuracy engineering applications. It is a thriving field of applied research with dedicated scientific conferences and engineering text books. Many designs have been put forward for linear motors, falling into two major categories, low-acceleration and high-acceleration linear motors. Low-acceleration linear motors are suitable for maglev trains and other ground-based transportation app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Window
The plasma window (not to be confused with a ''plasma shield'') is a technology that fills a volume of space with plasma confined by a magnetic field. With current technology, this volume is quite small and the plasma is generated as a flat plane inside a cylindrical space. Plasma is any gas whose atoms or molecules have been ionized, and is a separate phase of matter. This is most commonly achieved by heating the gas to extremely high temperatures, although other methods exist. Plasma becomes increasingly viscous at higher temperatures, to the point where other matter has trouble passing through. A plasma window's viscosity allows it to separate gas at standard atmospheric pressure from a total vacuum, and can reportedly withstand a pressure difference of up to nine atmospheres. At the same time, the plasma window will allow radiation such as lasers and electron beams to pass. This property is the key to the plasma window's usefulness — the technology of the plasma windo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maglev (transport)
Maglev (derived from ''magnetic levitation''), is a system of train transportation that uses two sets of electromagnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction. Such trains rise approximately off the track. There are both high speed, intercity maglev systems (over ), and low speed, urban maglev systems ( to ) being built and under construction and development. With maglev technology, the train travels along a guideway of electromagnets which control the train's stability and speed. While the propulsion and levitation require no moving parts, the bogies can move in relation to the main body of the vehicle and some technologies require support by retractable wheels at low speeds under . This compares with electric multiple units that may have several dozen parts per bogie. Maglev trains can therefore in some cases be quieter and smoother than conventional trains and have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maglev
Maglev (derived from '' magnetic levitation''), is a system of train transportation that uses two sets of electromagnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction. Such trains rise approximately off the track. There are both high speed, intercity maglev systems (over ), and low speed, urban maglev systems ( to ) being built and under construction and development. With maglev technology, the train travels along a guideway of electromagnets which control the train's stability and speed. While the propulsion and levitation require no moving parts, the bogies can move in relation to the main body of the vehicle and some technologies require support by retractable wheels at low speeds under . This compares with electric multiple units that may have several dozen parts per bogie. Maglev trains can therefore in some cases be quieter and smoother than conventional trains and have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Levitation
Magnetic levitation (maglev) or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational force and any other forces. The two primary issues involved in magnetic levitation are ''lifting forces'': providing an upward force sufficient to counteract gravity, and ''stability'': ensuring that the system does not spontaneously slide or flip into a configuration where the lift is neutralized. Magnetic levitation is used for maglev trains, contactless melting, magnetic bearings and for product display purposes. Lift Magnetic materials and systems are able to attract or repel each other with a force dependent on the magnetic field and the area of the magnets. For example, the simplest example of lift would be a simple dipole magnet positioned in the magnetic fields of another dipole magnet, oriented with like poles facing each other, so that the force between m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetohydrodynamics
Magnetohydrodynamics (MHD; also called magneto-fluid dynamics or hydromagnetics) is the study of the magnetic properties and behaviour of electrically conducting fluids. Examples of such magnetofluids include plasmas, liquid metals, salt water, and electrolytes. The word ''magnetohydrodynamics'' is derived from ' meaning magnetic field, ' meaning water, and ' meaning movement. The field of MHD was initiated by Hannes Alfvén, for which he received the Nobel Prize in Physics in 1970. The fundamental concept behind MHD is that magnetic fields can induce currents in a moving conductive fluid, which in turn polarizes the fluid and reciprocally changes the magnetic field itself. The set of equations that describe MHD are a combination of the Navier–Stokes equations of fluid dynamics and Maxwell’s equations of electromagnetism. These differential equations must be solved simultaneously, either analytically or numerically. History The first r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Mountains By Elevation
A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union club Other uses * Angle of list, the leaning to either port or starboard of a ship * List (information), an ordered collection of pieces of information ** List (abstract data type), a method to organize data in computer science * List on Sylt, previously called List, the northernmost village in Germany, on the island of Sylt * ''List'', an alternative term for ''roll'' in flight dynamics * To ''list'' a building, etc., in the UK it means to designate it a listed building that may not be altered without permission * Lists (jousting), the barriers used to designate the tournament area where medieval knights jousted * ''The Book of Lists'', an American series of books with unusual lists See also * The List (other) * Listing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. The term ''LEO region'' is also used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. All crewed space stations to date have been within LEO. From 1968 to 1972, the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, no human spaceflights have been beyond LEO. Defining characteristics A wide variety of sources define LEO in terms of altitude. The altitude of an object in an elliptic orbit can vary significantly along the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Rotation
Earth's rotation or Earth's spin is the rotation of planet Earth around its own axis, as well as changes in the orientation of the rotation axis in space. Earth rotates eastward, in prograde motion. As viewed from the northern polar star Polaris, Earth turns counterclockwise. The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where Earth's axis of rotation meets its surface. This point is distinct from Earth's North Magnetic Pole. The South Pole is the other point where Earth's axis of rotation intersects its surface, in Antarctica. Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes and 4 seconds with respect to other distant stars ( see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation. Atomic clocks show that a modern day is longer by about 1. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Speed
In gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter or, if one body is much more massive than the other bodies of the system combined, its speed relative to the center of mass of the most massive body. The term can be used to refer to either the mean orbital speed (i.e. the average speed over an entire orbit) or its instantaneous speed at a particular point in its orbit. The maximum (instantaneous) orbital speed occurs at periapsis (perigee, perihelion, etc.), while the minimum speed for objects in closed orbits occurs at apoapsis (apogee, aphelion, etc.). In ideal two-body systems, objects in open orbits continue to slow down forever as their distance to the barycenter increases. When a system approximates a two-body system, instantaneous orbital speed at a given point of the orbit can be computed from its distanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
