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Launch loops are intended to achieve [[non-rocket spacelaunch]] of [[SpacecraftStatek kosmiczny|vehicles]] weighing 5 metric tons by [[Maglev (transport)|electromagnetically accelerating]] them so that they are projected into Earth [[orbitOrbita|Orbit]] or even beyond. This would be achieved by the flat part of the cable which forms an acceleration track above the atmosphere.<ref>Indistinguishable from Magic- [[Robert L. Forward]], chapter 4.</ref>

The system is designed to be suitable for launching humans for [[spaceTurysta kosmiczny|Space tourism]], [[spaceEksploracja kosmosu|Space exploration]] and [[spaceKolonizacja kosmosu|Space colonization]], and provides a relatively low [[g-force|3''g'' acceleration]].<ref name=launch1985/>

A launch loop is proposed to be a structure around 2,000&nbsp;km long and 80&nbsp;km high. The loop runs along at 80&nbsp;km above the earth for 2000&nbsp;km then descends to earth before looping back on itself rising back to 80&nbsp;km above the earth to follow the reverse path then looping back to the starting point. The loop would be in the form of a tube, known as the ''sheath''. Floating within the sheath is another continuous tube, known as the ''rotor'' which is a sort of belt or chain. The rotor is an [[ironŻelazo|Iron]] tube approximately 5&nbsp;cm (2&nbsp;inches) in diameter, moving around the loop at 14&nbsp;km/s (31,000 miles per hour).<ref name=launch1985/>

When at rest, the loop is at ground level. The rotor is then accelerated up to speed. As the rotor speed increases, it curves to form an arc. The sheath forces it to follow a curve steeper than the rotor's natural ballistic curve, which, in turn, exerts a [[reactiveSiła odśrodkowa|Reactive centrifugal force]] on the sheath, holding it aloft. The loop would be anchored to the ground to remain at a fixed height.

To launch, vehicles are raised up on an 'elevator' cable that hangs down from the West station loading dock at 80&nbsp;km, and placed on the track. The payload applies a magnetic field which generates [[eddyPrąd wirowy|Eddy current]]s in the fast-moving rotor. This both lifts the payload away from the cable, as well as pulls the payload along with 3''g'' (30 m/s²) acceleration. The payload then rides the rotor until it reaches the required orbital velocity, and leaves the track.<ref name=launch1985/>

If a stable or circular orbit is needed, once the payload reaches the highest part of its trajectory then an on-board [[rocketSilnik rakietowy|Rocket engine]] ("kick motor") or other means is needed to circularize the trajectory to the appropriate Earth orbit.<ref name=launch1985>[http://launchloop.com/LaunchLoop?action=AttachFile&do=get&target=launchloop.pdf PDF version of Lofstrom's 1985 launch loop publication (AIAA conference)]</ref>

The eddy current technique is compact, lightweight and powerful, but inefficient. With each launch the rotor temperature increases by 80 [[kelvinKelwin|Kelvin]]s due to power dissipation. If launches are spaced too close together, the rotor temperature can approach 770 °C (1043 K), at which [[Curie point|point]] the iron rotor loses its [[ferromagnetismFerromagnetyzm|ferromagnetic]] properties and rotor containment is lost.<ref name=launch1985/>

Closed orbits with a perigee of 80&nbsp;km quite quickly decay and re-enter, but in addition to such orbits, a launch loop by itself would also be capable of directly injecting payloads into [[escapePrędkość velocityucieczki|escape orbits]], [[gravityAsysta grawitacyjna|Gravity assist]] trajectories past the [[Księżyc|Moon]], and other non closed orbits such as close to the [[Trojan_points#L4_and_L5|Trojan points]].

To access circular orbits using a launch loop a relatively small 'kick motor' would need to be launched with the payload which would fire at [[apogee]] and would circularise the orbit. For [[geosynchronousOrbita orbitgeosynchroniczna|GEO]] insertion this would need to provide a [[deltaDelta-v|Delta-v]] of about 1.6&nbsp;km/s, for [[LowNiska Earthorbita orbitokołoziemska|LEO]] to circularise at 500&nbsp;km would require a delta-v of just 120 m/s. Conventional [[rocketRakieta|Rocket]]s require delta-vs of roughly 10 and 14&nbsp;km/s to reach LEO and GEO respectively.<ref name=launch1985/>

Finally, their low payload costs are compatible with large-scale commercial [[spaceTurysta kosmiczny|Space tourism]] and even [[space colonisation]].

A running loop would have an extremely large amount of energy in the form of linear momentum. While the magnetic suspension system would be highly redundant, with failures of small sections having essentially no effect at all, if a major failure did occur the energy in the loop (1.5×10¹⁵ [[jouleDżul|Joule]]s or 1.5 petajoules) would be approaching the same total ''energy'' release as a [[nuclear bomb]] explosion (350 kilotons of [[Równoważnik trotylowy wybuchu jądrowego|TNT equivalent]]), although not emitting nuclear radiation.

The cable sections also share this potential issue, although the forces are much lower.<ref name=launch1985/> However, an additional instability is present in that the cable/sheath/rotor may undergo [[meanderMeander (geografia)|Meander]]ing modes (similar to a [[Lariat chain]]) that grow in amplitude without limit. Lofstrom believes that this instability also can be controlled in real time by servo mechanisms, although this has never been attempted.

* [[Kolejka górska|Roller coaster]]/[[Mass driver]]

* [[Winda kosmiczna|Space elevator]]

* [[Turysta kosmiczny|Space tourism]]

* [[cyclotronCyklotron|Cyclotron]] - the magnetic fields necessary to deflect the loop are similar to a cyclotron

* [[Siła odśrodkowa|Reactive centrifugal force]] - the force that would hold up the loop against gravity