- Impulse drive
In the fictional "
Star Trek " universe, the impulse drive is the method of propulsion thatstarships and otherspacecraft use when they are travelling below thespeed of light . [] Typically powered bynuclear fusion reactions, impulse engines let ships travel interplanetary distances readily. For example,Starfleet Academy cadets use impulse engines when flying fromEarth to Saturn and back.There are three practical challenges surrounding impulse drive design:
acceleration ,time dilation andenergy conservation . In the show, inertial dampers compensate for acceleration. These hypothetical devices would have to be set so that the propellant regained its inertia after leaving the craft otherwise the drive would be ineffective. [citation|title=Energy Considerations of Hypothetical Space Drives|author=Marc G. Millis|url=http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070031912_2007031208.pdf|pages=3|publisher=American Institute of Aeronautics and Astronautics|year=2007]Time dilation would become noticeable at appreciable fractions of the speed of light. Regarding energy conservation, the television series and books offer two explanations:*"" indicates that the impulse engines are nuclear fusion engines whereas the plasma from the fusion reactor powers a massive magnetic coil to propel the ship. It is a form of
magnetoplasmadynamic thruster . This is used in conjunction with the ship's warp drive's alteration of the ships relativistic mass, to achieve mid-to-high sub-light speeds. Thrusters, on the other hand, are closer to the designs of a high-efficiency reactant propellant (i.e. a sophisticated rocket engine) and are usually used for high-precision maneuvers. Ion propulsion drives are explicitly detailed to be used in "Star Trek " by Dominion andIconian Starships and facilities.* Since a ship traveling at impulse velocities (slower than, but approaching, the speed of light) is still traveling in the normal space-time continuum, concerns of
time dilation apply, so high relativistic speeds are avoided unless absolutely necessary; impulse power is therefore customarily limited to a maximum of ¼ lightspeed. (Warp travel, on the other hand, does not involve time dilation effects.)Impulse Drives are also found in the online space simulation MMORPG,
Ogame . However,Ogame 's fictional definition states it is a faster-than-light transport propulsion system.References
ee also
*
Physics and Star Trek
*Physics and Star Wars
*Warp drive
*
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