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Encyclopedia > Mass driver
A mass driver for lunar launch (artist's conception)
A mass driver for lunar launch (artist's conception)

A mass driver or electromagnetic catapult is a method of spacecraft propulsion that would use a linear motor to accelerate payloads up to high speeds. All existing and contemplated mass drivers use coils of wire energized by electricity to make electromagnets. Sequential firing of a row of electromagnets accelerates the payload along a path. After leaving the path, the payload continues to move due to inertia. Download high resolution version (1023x675, 507 KB)Lunar base concept drawing from NASA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Download high resolution version (1023x675, 507 KB)Lunar base concept drawing from NASA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... It has been suggested that Heavy Catapult be merged into this article or section. ... A remote camera captures a close-up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Propulsion means to add speed or acceleration to an object, by an engine or other similar device. ... A linear motor is essentially a multi-phase alternating current (AC) electric motor that has had its stator unrolled so that instead of producing a torque (rotation) it produces a linear force along its length. ... Acceleration is the time rate of change of velocity, and at any point on a v_t graph, it is given by the gradient of the tangent to that point In physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. ... In cargo transport, the payload is the valuable contents of the vehicle. ... In physics, velocity is defined as the rate of change of displacement or the rate of displacement. ... A coil is a series of loops. ... Lightning strikes during a night-time thunderstorm. ... An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. ... An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. ... Acceleration is the time rate of change of velocity, and at any point on a v_t graph, it is given by the gradient of the tangent to that point In physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. ... In cargo transport, the payload is the valuable contents of the vehicle. ... In cargo transport, the payload is the valuable contents of the vehicle. ... Inertia is the property of an object to remain at constant velocity unless acted upon by an outside force. ...

Contents

Overview

A mass driver is essentially a coil gun that magnetically accelerates a package consisting of a magnetisable holder containing a payload. Once the payload has been accelerated, the two separate, and the holder is slowed and recycled for another payload. A coilgun (or Gauss gun) is a type of cannon that uses a series of electromagnets to accelerate a magnetic shell to very high velocities. ...


The first mass driver known in print was actually called the "electric gun" and described in detail as a way to launch vehicles into outer space from the earth's surface in the 1897 no longer copyrighted science fiction novel 'A trip to venus by John Munro' and published in 1897 by Jarrold & Sons, London. The book is out of copyright and freely available as a text file from the project gutenberg.org website at http://www.gutenberg.org/etext/13716 .


John Munro was also author of the "The Wire and the Wave," and "The Story of Electricity," etc.


In the book Munro describes in great detail multiple coils fired in sequence by solenoids at proper timing to achieve acceleration without too high g forces to the passengers. The gun would be angled on a hillside if desired. Amazingly this book also describes in detail combinations of electric gun launch for a passenger capsule with onboard rockets, compressed gas jets and even retrofired bullets as a means to increase velocity and change direction and the use of planetary atmosphere aerobraking and parachutes for landing on a planet.


Prototype mass drivers have existed since 1976 (Mass Driver 1). Most were constructed by the US Space Studies Institute in order to prove their properties and practicality. Mass drivers can be used to propel spacecraft in two different ways: A large, ground-based mass driver could be used to launch spacecraft away from the Earth or another planet. A spacecraft could have a mass driver on board, flinging large pieces of material into space to propel itself. A hybrid design is also possible (see coil gun, railgun, or helical railgun) Year 1976 (MCMLXXVI) was a leap year starting on Thursday (link will display full calendar) of the 1976 Gregorian calendar. ... Constructed in 1976 and 1977, Mass Driver 1 was an early demonstration of the concept of the mass driver, a form of electromagnetic launch. ... Cover of procedings for 7th Space Manufacturing conference. ... Uses of the word launch: A launch can be a type of boat: see launch (boat). ... A coilgun (or Gauss gun) is a type of cannon that uses a series of electromagnets to accelerate a magnetic shell to very high velocities. ... // A railgun is a form of gun that converts electrical energy (rather than the more conventional chemical energy from an explosive propellant) into projectile kinetic energy. ... A railgun is in essence a single-turn motor. ...


Fixed mass drivers

Generally speaking, mass drivers are only practical for small objects at a few kilometers per second; for example 1kg at 2.5km/s. Heavier objects go proportionally more slowly; and lighter objects may be projected at 20km/s or more. The limits are generally the cost of the silicon to switch the current and the cost of the power supply and temporary energy storage for it. Earth based Mass drivers for propelling one tonne vehicles to orbit are unlikely to be cost effective in the near future.


The Earth's strong gravity and thick atmosphere make such an installation difficult. So, many proposals have been put forward to install mass drivers on the moon where the lower gravity and lack of atmosphere significantly reduce the costs. Apparent magnitude: up to -12. ... Gravity is a force of attraction that acts between bodies that have mass. ...


Most serious mass driver designs use superconducting coils to achieve reasonable energetic efficiency (approximately 50%). The best known performance occurs with an aluminum coil as the payload. The coils of the mass-driver induce eddy-currents in the payload's coil, and then act on the resulting magnetic field. There are two sections of a mass-driver. The maximum acceleration part spaces the coils at constant distances, and synchronize the coil currents to the bucket. In this section, the acceleration increases as the velocity increases, up to the maximum that the bucket can take. After that, the constant acceleration region begins. This region spaces the coils at increasing distances to give a fixed amount of velocity increase per unit of time. Magnetic field lines shown by iron filings In physics, a magnetic field is a solenoidal vector field in the space surrounding moving electric charges, such as those in electric currents and bar magnets. ... Acceleration is the time rate of change of velocity, and at any point on a velocity-time graph, it is given by the slope of the tangent to that point basicly. ...


In the prototypes, the payload would be held in a bucket and then released, so that the bucket can be decelerated and reused.


In this mode, the major proposal for use of mass-drivers was to transport lunar surface material to space habitats so that it could be processed using solar energy. The Space Studies Institute showed that this application was reasonably practical. Solar power describes a number of methods of harnessing energy from the light of the sun. ...


A possibility for building a mass driver on Earth is a compromise system: a mass driver accelerates a payload up to some high speed which is not high enough for launch. It then releases the payload, which completes the launch under its own power. This would drastically reduce the amount of thrust that would be required for a launch, while allowing the mass driver design to use well-tested maglev components. Shanghai Maglev Train stopping at terminus Longyang Road station Transrapid Shanghai Maglev Train Inside the Shanghai Transrapid maglev Inside the Shanghai Transrapid maglev VIP section Magnetic levitation transport, or maglev, is a form of transportation that suspends, guides and propels vehicles (especially trains) via electromagnetic force. ...


Spacecraft-based mass drivers

A spacecraft could carry a mass driver as its primary engine. With a suitable source of electrical power (probably a nuclear reactor) the spaceship could then use the mass driver to accelerate pieces of matter of almost any sort, boosting itself in the opposite direction. The Space Shuttle Discovery as seen from the International Space Station. ... Core of a small nuclear reactor used for research. ...


Since current linear motors can accelerate cargo to 30 km/s, an engine using one would have a specific impulse of about 30 km/s or 3,000 s. No theoretical limit is known for the size, acceleration or muzzle energy of linear motors. However, at higher muzzle velocities, energetic efficiency is inevitably very poor. While linear motors can, with current technology, convert up to about 50% of the electrical energy into kinetic energy of the projectile, the energy of interest is the kinetic energy of the vehicle, and as the muzzle velocity increases, this is a smaller and smaller percentage of the generated power. A linear motor is essentially a multi-phase alternating current (AC) electric motor that has had its stator unrolled so that instead of producing a torque (rotation) it produces a linear force along its length. ... kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s-1. ... Specific impulse (usually abbreviated Isp) is a way to describe the efficiency of rocket and jet engines. ...


Since kinetic energy of the projectile is mv2/2, the energy requirements vary with the square of the specific impulse, so in a design one must choose a tradeoff between energy consumption and consumption of reaction mass. In addition, since momentum of a particle of mass m has momentum mv- proportional to velocity, but energy is a square law, so the average thrust for a given energy is inversely proportional to the velocity of the particles. In other words, heavier projectile masses give lower specific impulse but proportionately higher thrust. Specific impulse (usually abbreviated Isp) is a way to describe the efficiency of rocket and jet engines. ...


Since a mass driver could use any type of mass for reaction mass to move the spacecraft, this, or some variation, seems ideal for deep-space vehicles that scavenge reaction mass from found resources.


One possible drawback of the mass driver is that it has the potential to send solid reaction mass travelling at dangerously high relative speeds into useful orbits and traffic lanes. To overcome this problem, most schemes plan to throw finely-divided dust. Propelling the reaction mass to solar escape velocity is another way to ensure that it will not remain a hazard. Look up dust in Wiktionary, the free dictionary. ...


As with all propulsion systems most of space is almost completely empty, so propellant sources are only to be found at asteroids, comets, moons and planets.


Another use for mass drivers on board spacecraft is as a means of launching smaller vessels from an internal hangar (akin to an aircraft catapult.) Such mass drivers would mainly be deployed on military vessels as a means of launching combat units into the battlefield rapidly, though it is possible that a commercial vessel might use a mass driver launcher for probes or exploratory vessels. u suk usuk u suk u suk u suk u suk u suk u suk u suk u suk usuk suk suk suk suk suk suk suk suk suk suk suk suk suk suk suk suk{| class=wikitable |- ! header 1 ! header 2 ! header 3 |- | row 1, cell 1 | row 1...


Hybrid mass drivers

Another variation is to have a mass-driver on a spacecraft, and use it to "reflect" masses from a stationary mass-driver. Each deceleration and acceleration of the mass contributes to the momentum of the spacecraft. The spacecraft need not carry reaction mass, and doesn't even need much electricity, beyond the amount needed to replace losses in the electronics. The system could also be used to deliver pellets of fuel to the spacecraft for use in powering some other propulsion system. This could be considered a form of beam-powered propulsion. The Space Shuttle Discovery as seen from the International Space Station. ... In classical mechanics, momentum (pl. ... Working mass is a mass against which a system operates in order to produce acceleration. ... Beam-powered propulsion is a class of spacecraft propulsion mechanisms that use energy beamed to the spacecraft from a remote power plant. ...


Another theoretical use for this concept of propulsion can be found in space fountains, a system in which a continuous stream of pellets in a circular track hold up a tall (and heavy) structure. The space fountain concept is a proposed form of space elevator that does not require the structure to be in geosynchronous orbit, and does not rely on tensile strength for support. ...


Mass drivers as weapons

High-acceleration linear motors are currently undergoing active research by the military for use as (ground-based) armor-piercing weapons. Since a mass driver is essentially a very large, very high-velocity linear motor, it could in principle be used as a very large weapon, either firing directly on a target in space, or used to attack a location on a planet's surface from a position in orbit, long range over-the-horizon indirect fire, or from a nearby planetary body, such as a moon. A linear motor is essentially a multi-phase alternating current (AC) electric motor that has had its stator unrolled so that instead of producing a torque (rotation) it produces a linear force along its length. ... An Armour piercing shell is a type of ammunition designed to penetrate armour. ... Orbital bombardment is the act of attacking targets on a planet, moon or other such object from orbit around the object, rather than from an aircraft or a platform beyond orbit. ... Apparent magnitude: up to -12. ...


Mass drivers in science fiction

In the computer game Descent 3, the mass driver is a weapon that can be attached to your ship's hull which fires a lethal projectile at its target. A computer game is a game composed of a computer-controlled virtual universe that players interact with in order to achieve a defined goal or set of goals. ... Descent³ is the third and final game in the line of Descent computer games, well known for the use of six degrees of freedom and true 3D rendering technology. ...


In the novel The Moon Is a Harsh Mistress mass drivers are used by Lunar rebels to launch artificial meteorites in an orbital bombardment of the Earth. The Moon Is A Harsh Mistress cover The Moon Is a Harsh Mistress is a 1966 science fiction novel by Robert A. Heinlein about a lunar penal colonys revolt against rule from Earth. ... Orbital bombardment is the act of attacking targets on a planet, moon or other such object from orbit around the object, rather than from an aircraft or a platform beyond orbit. ...


In the game Ace Combat 5: The Unsung War a mass driver was used to send supplies to the Arkbird. The Arkbird is a giant superweapon from the Playstation 2 video game Ace Combat 5. ...


In the Babylon 5 episode The Long, Twilight Struggle, the Centauri Republic used mass drivers in violation of their treaties in their final attack on the Narn homeworld. Babylon 5 is an epic American science fiction television series created, produced, and largely written by J. Michael Straczynski. ... The Long, Twilight Struggle is an episode from the second season of the science-fiction television series Babylon 5. ... For other uses, see Centauri (disambiguation). ... Andreas Katsulas as GKar in Babylon 5 The Narns are a race of humanoid aliens in the television series Babylon 5. ...


In the Japanese anime Gundam Seed mass drivers are used to launch warships into space. This was prominent in the Battle of Orb. Title of the series Mobile Suit Gundam SEED (or Gundam Seed) is an anime television series from Japan. ... Spoiler warning: In the Cosmic Era alternate universe of Gundam, the Bloody Valentine War is a war between the Earth Alliance, an alliance of four major governments on Earth, ZAFT, a nation of space colonies located at L5, and the Clyne Faction, an alliance of Earth Alliance and ZAFT defectors...


In Tekkaman Blade II & Teknoman they are used to launch the blue earth into a high orbit, where the blue earths engines can take them either into space or around the planet. Tekkaman Blade II , literally Space Knight Tekkaman Blade II) is a 6 episode Original Video Animation. ... Teknoman is the English-dubbed version of the Japanese anime Uchuu no Kishi Tekkaman Blade (宇宙の騎士テッカマンブレード Star Knight Tekkaman Blade). This series was intended to be a revamp of the original Tekkaman: The Space Knight anime, though these shows ultimately shared little in common besides the armoured hero concept The original...


In the game Star Wars: Empire at War: Forces of Corruption the Zann Consortium uses mass drivers as a weapon on many of their starships. The Zann Consortium is a criminal organization depicted in the computer game Star Wars: Empire at War: Forces of Corruption. ...


In the game Xenogears, the main characters use a mass driver to expel a cure for a disease into the atmosphere, saving the planet. Xenogears ) is a console role-playing game developed and published by Square Co. ...


In the novel The Two Faces of Tomorrow by James P. Hogan, a Maskelyne mass driver based in the Sea of Tranquility is used by the TITAN supercomputer to easily destroy a lunar ridge that needed to be cleared for the construction of a second mass driver site. The name James P. Hogan might refer to: The science fiction writer The film maker This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The Sea of Tranquility of the Moon. ...


In the game Masters of Orion II, the mass driver is a weapon that can be equipped on ships; its damage does not decrease with range.


See also

A coilgun (not to be confused with a railgun) is a type of cannon which uses one or more electromagnetic coils to accelerate a magnetic projectile to high velocity. ... A linear motor is essentially a multi-phase alternating current (AC) electric motor that has had its stator unrolled so that instead of producing a torque (rotation) it produces a linear force along its length. ... // A railgun is a form of gun that converts electrical energy (rather than the more conventional chemical energy from an explosive propellant) into projectile kinetic energy. ... A railgun is in essence a single-turn motor. ... A remote camera captures a close-up view of a Space Shuttle Main Engine during a test firing at the John C. Stennis Space Center in Hancock County, Mississippi Propulsion means to add speed or acceleration to an object, by an engine or other similar device. ...

People

Eric Roberts Laithwaite (14 June 1921 – 27 November 1997) was an English engineer, principally known for his development of the linear induction motor and Maglev rail system. ... Gerard Kitchen ONeill (1927 - 1992) was a U.S. physicist and space pioneer. ... Henry Herbert Kolm is an American physicist. ...

External links

  • Electromagnetic Guns - A page describing recent research into linear motors at MIT.
  • Electromagnetic Launch of Lunar Material
  • New Scientist: Huge 'launch ring' to fling satellites into orbit - October 2006 article about research into a circular mass driver.

  Results from FactBites:
 
Mass driver - Wikipedia, the free encyclopedia (2319 words)
A mass driver is essentially a coil gun that magnetically accelerates a bucket device carrying a payload.
Mass drivers can be used to propel spacecraft in two different ways: A large, ground-based mass driver can be used to launch spacecraft away from the Earth or another planet, or a spacecraft could have a mass driver on board, flinging large pieces of material into space to propel itself.
Mass drivers seem to be somewhat widespread in the UC timeline, with notable examples located at Hong Kong on Earth, and Anaheim Electronics' factory on Luna.
PERMANENT - Transportation - Mass Drivers (3074 words)
The "mass driver" is a "catapult" tube which launches materials from the lunar surface to a Catcher/Collector, perhaps near a factory in orbit near the Moon.
The mass driver is made of a small variety of parts, all simple and repeated in a modular way which expedites simple replacement and maintenance using a small stock of spares in case of a small failure.
With the pull-only mass driver, no mechanical guidance means is needed to keep the bucket from crashing into a drive coil because the pull-only magnetic field of the drive coils strongly forces the bucket to levitate along the center of the drive coil tunnel.
  More results at FactBites »

 
 

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