545:) forces, but when tied together by a tether, these values begin to change with respect to one another. This phenomenon occurs because, without the tether, the higher-altitude mass would travel slower than the lower mass. The system must move at a single speed, so the tether must therefore slow down the lower mass and speed up the upper one. The centrifugal force of the tethered upper body is increased, while that of the lower-altitude body is reduced. This results in the centrifugal force of the upper body and the gravitational force of the lower body being dominant. This difference in forces naturally aligns the system along the local vertical, as seen in the figure.
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Correct tapering ensures that the tensile stress at every point in the cable is exactly the same. For very demanding applications, such as an Earth space elevator, the tapering can reduce the excessive ratios of cable weight to payload weight. In lieu of tapering a modular staged tether system maybe used to achieve the same goal. Multiple tethers would be used between stages. The number of tethers would determine the strength of any given cross-section.
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either end of the tether will experience continuous acceleration; the magnitude of the acceleration depends on the length of the tether and the rotation rate. Momentum exchange occurs when an end body is released during the rotation. The transfer of momentum to the released object will cause the rotating tether to lose energy, and thus lose velocity and altitude. However, using
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Large pieces of junk would still cut most tethers, including the improved versions listed here, but these are currently tracked on radar and have predictable orbits. Although thrusters could be used to change the orbit of the system, a tether could also be temporally wiggled in the right place, using
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A non-rotating tether system has a stable orientation that is aligned along the local vertical (of the earth or other body). This can be understood by inspection of the figure on the right where two spacecraft at two different altitudes have been connected by a tether. Normally, each spacecraft would
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exchange tethers are one of many applications for space tethers. Momentum exchange tethers come in two types; rotating and non-rotating. A rotating tether will create a controlled force on the end-masses of the system due to centrifugal acceleration. While the tether system rotates, the objects on
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Mechanical tether-handling equipment is often surprisingly heavy, with complex controls to damp vibrations. The one ton climber proposed by Brad
Edwards for his Space Elevator may detect and suppress most vibrations by changing speed and direction. The climber can also repair or augment a tether by
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One plan to control the vibrations is to actively vary the tether current to counteract the growth of the vibrations. Electrodynamic tethers can be stabilized by reducing their current when it would feed the oscillations, and increasing it when it opposes oscillations. Simulations have demonstrated
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Cargo capture for rotovators is nontrivial, and failure to capture can cause problems. Several systems have been proposed, such as shooting nets at the cargo, but all add weight, complexity, and another failure mode. At least one lab scale demonstration of a working grapple system has been achieved,
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Tether properties and materials are dependent on the application. However, there are some common properties. To achieve maximum performance and low cost, tethers would need to be made of materials with the combination of high strength or electrical conductivity and low density. All space tethers are
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has successfully flown a long term 6-kilometer (3.7 mi) long, 2β3-millimeter (0.079β0.118 in) diameter tether with an outer layer of
Spectra 1000 braid and a core of acrylic yarn. This satellite, the Tether Physics and Survivability Experiment (TiPS), was launched in June 1996 and remained
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A theoretical type of non-rotating tethered satellite system, it is a concept for providing space-based support to things suspended above an astronomical object. The orbital system is a coupled mass system wherein the upper supporting mass (A) is placed in an orbit around a given celestial body such
930:. M5 is a synthetic fiber that is lighter than Kevlar or Spectra. According to Pearson, Levin, Oldson, and Wykes in their article "The Lunar Space Elevator", an M5 ribbon 30 mm (1.2 in) wide and 0.023 mm (0.91 mils) thick, would be able to support 2,000 kg (4,400 lb) on the
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and are analogous to specific impulse or exhaust velocity. The higher these values are, the more efficient and lighter the tether can be in relation to the payloads that they can carry. Eventually however, the mass of the tether propulsion system will be limited at the low end by other factors such
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obtain 10 to 20 GPa (1.5 to 2.9 million psi; 99,000 to 197,000 atm) in some samples on the nano scale, but translating such strengths to the macro scale has been challenging so far, with, as of 2011, CNT-based ropes being an order of magnitude less strong, not yet stronger than
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For gravity stabilized tethers, to exceed the self-support length the tether material can be tapered so that the cross-sectional area varies with the total load at each point along the length of the cable. In practice this means that the central tether structure needs to be thicker than the tips.
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Electrodynamic tethers deployed along the local vertical ('hanging tethers') may suffer from dynamical instability. Pendular motion causes the tether vibration amplitude to build up under the action of electromagnetic interaction. As the mission time increases, this behavior can compromise the
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For some applications, the tensile force on the tether is projected to be less than 65 newtons (15 lbf). Material selection in this case depends on the purpose of the mission and design constraints. Electrodynamic tethers, such as the one used on TSS-1R, may use thin copper wires for high
1428:
1851:) aircraft could deliver a payload to a rotovator that dipped into Earth's upper atmosphere briefly at predictable locations throughout the tropic (and temperate) zone of Earth. As of May 2013, all mechanical tethers (orbital and elevators) are on hold until stronger materials are available.
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1827:; redundancy can ensure that it is very unlikely that multiple redundant cables would be damaged near the same point on the cable, and hence a very large amount of total damage can occur over different parts of the cable before failure occurs.
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designs, rotation of the cable interacting with the non-linear gravity fields found in elliptical orbits can cause exchange of orbital angular momentum and rotation angular momentum. This can make prediction and modelling extremely complex.
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surface. It would also be able to hold 100 cargo vehicles, each with a mass of 580 kg (1,280 lb), evenly spaced along the length of the elevator. Other materials that could be used are T1000G carbon fiber, Spectra 2000, or Zylon.
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intended to lift payloads to high altitudes and speeds. Proposals for skyhooks include designs that employ tethers spinning at hypersonic speed for catching high speed payloads or high altitude aircraft and placing them in orbit.
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In 1990, Eagle
Sarmont proposed a non-rotating Orbiting Skyhook for an Earth-to-orbit / orbit-to-escape-velocity Space Transportation System in a paper titled "An Orbiting Skyhook: Affordable Access to Space". In this concept a
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are not usually colocated. Thus the inverse square law does not apply except at large distances, to the overall behaviour of a tether. Hence the orbits are not completely
Keplerian, and in some cases they are actually chaotic.
679:(20.3 and 25.7 million psi; 1.38 and 1.75 million atm), and a proven tensile strength in the range 50β60 GPa (7.3β8.7 million psi; 490,000β590,000 atm) for some individual nanotubes. (A
1578:{\displaystyle {\frac {M}{m}}={\sqrt {\pi {\frac {\delta }{T}}{\frac {V^{2}}{2}}}}\mathrm {e} ^{\left({\frac {\delta }{T}}{\frac {V^{2}}{2}}\right)}\mathrm {erf} \left({\sqrt {{\frac {\delta }{T}}{\frac {V^{2}}{2}}}}\right)}
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performance of the system. Over a few weeks, electrodynamic tethers in Earth orbit might build up vibrations in many modes, as their orbit interacts with irregularities in magnetic and gravitational fields.
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For rotating tethers not significantly affected by gravity, the thickness also varies, and it can be shown that the area, A, is given as a function of r (the distance from the centre) as follows:
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For rotating tethers (rotovators) the value used is the material's 'characteristic velocity' which is the maximum tip velocity a rotating untapered cable can attain without breaking,
432:, converting electrical energy to kinetic energy. Electric potential is generated across a conductive tether by its motion through the Earth's magnetic field. The choice of the metal
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Currently, the strongest materials in tension are plastics that require a coating for protection from UV radiation and (depending on the orbit) erosion by atomic oxygen. Disposal of
1811:, which is proportional to a simple exponent on a velocity, rather than a velocity squared. This difference effectively limits the delta-v that can be obtained from a single tether.
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G. Colombo, E. M. Gaposchkin, M. D. Grossi, and G. C. Weiffenbach, βThe sky-hook: a shuttle-borne tool for low-orbital-altitude research,β Meccanica, vol. 10, no. 1, pp. 3β20, 1975.
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A tether is not a spherical object, and has significant extent. This means that as an extended object, it is not directly modelable as a point source, and this means that the
1843:) permit rotovators to pluck masses from the surface of the Moon and Mars, a rotovator from these materials cannot lift from the surface of the Earth. In theory, high flying,
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Another proposed method is to use spinning electrodynamic tethers instead of hanging tethers. The gyroscopic effect provides passive stabilisation, avoiding the instability.
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For applications that exert high tensile forces on the tether, the materials need to be strong and light. Some current tether designs use crystalline plastics such as
125:, that capture an arriving spacecraft and then release it at a later time into a different orbit with a different velocity. Momentum exchange tethers can be used for
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susceptible to space debris or micrometeoroids. Therefore, system designers will need to decide whether or not a protective coating is needed, including relative to
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Hypersonic skyhook equations use the material's "specific velocity" which is equal to the maximum tangential velocity a spinning hoop can attain without breaking:
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1925:), damaged electronics, and welded tether handling machinery. It may be that the Earth's magnetic field is not as homogeneous as some engineers have believed.
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idea, a type of synchronous tether that would rotate with the Earth. However, given the materials technology of the time, this too was impractical on Earth.
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258:, also known as rotating skyhooks, and performed detailed simulations of tapered rotating tethers that could pick objects off, and place objects onto, the
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There are design equations for certain applications that may be used to aid designers in identifying typical quantities that drive material selection.
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patented an engineered circular net, such that a cut strand's strains would be redistributed automatically around the severed strand. This is called a
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Integrating the area to give the volume and multiplying by the density and dividing by the payload mass gives a payload mass / tether mass ratio of:
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connected to another by a space tether. A number of satellites have been launched to test tether technologies, with varying degrees of success.
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would fly to the bottom end of a
Skyhook, while spacecraft bound for higher orbit, or returning from higher orbit, would use the upper end.
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Instead of rotating end for end, tethers can also be kept straight by the slight difference in the strength of gravity over their length.
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Beanstalks and rotovators are currently limited by the strengths of available materials. Although ultra-high strength plastic fibers (
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Jillian Scharr, "Space
Elevators On Hold At Least Until Stronger Materials Are Available, Experts Say", Huffington Post, May 29, 2013
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Electrodynamic tethers are primarily used for propulsion. These are conducting tethers that carry a current that can generate either
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independently conceived the idea of a space elevator, sometimes referred to as a synchronous tether, and, in particular, analyzed a
1376:{\displaystyle A(r)={\frac {Mv^{2}}{TR}}\mathrm {e} ^{{\frac {\delta }{T}}{\frac {v^{2}}{2}}\left(1-{\frac {r^{2}}{R^{2}}}\right)}}
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Graphic of the US Naval
Research Laboratory's TiPS tether satellite. Only a small part of the 4 km tether is shown deployed.
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Radiation, including UV radiation tend to degrade tether materials, and reduce lifespan. Tethers that repeatedly traverse the
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that this can control tether vibration. This approach requires sensors to measure tether vibrations, which can either be an
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are long conducting wires, such as one deployed from a tether satellite, which can operate on electromagnetic principles as
2773:"Tether Transport from LEO to the Lunar Surface", R. L. Forward, AIAA Paper 91-2322, 27th Joint Propulsion Conference, 1991
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that it can support a suspended mass (B) at a specific height above the surface of the celestial body, but lower than (A).
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examined the feasibility of the idea and gave direction to the study of tethered systems, especially tethered satellites.
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Smitherman, D.V., "Space
Elevators, An Advanced Earth-Space Infrastructure for the New Millennium", NASA/CP-2000-210429
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209:(1857β1935) once proposed a tower so tall that it reached into space, so that it would be held there by the rotation of
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Ultra Long
Orbital WSEAS TRANSACTIONS on MATHEMATICS: Tethers Behave Highly Non-Keplerian and Unstable- Daniele Mortari
705:, which is also known as its "self-support length" and is the length of untapered cable it can support in a constant 1
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42:
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2836:"NASA - NASA Engineers, Tennessee College Students Successfully Demonstrate Catch Mechanism for Future Space Tether"
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Tethers are nearly always tapered, and this can greatly amplify the movement at the thinnest tip in whip-like ways.
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Graph of tether mass to payload ratio versus the tip speed in multiples of the characteristic speed of the material
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to be used in an electrodynamic tether is determined by a variety of factors. Primary factors usually include high
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concept, where a rotating tether would take payloads from a hypersonic aircraft (at half of orbital velocity) to
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can have markedly lower life than those that stay in low earth orbit or are kept outside Earth's magnetosphere.
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2881:"Ultra Long Orbital Tethers Behave Highly Non-Keplerian and Unstable | Daniele Mortari - Academia.edu"
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NASA Engineers, Tennessee
College Students Successfully Demonstrate Catch Mechanism for Future Space Tether
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Description of the forces contributing towards maintaining a gravity gradient alignment in a tether system
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The vibration modes that may be a problem include skipping rope, transverse, longitudinal, and pendulum.
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L. Johnson, B. Gilchrist, R. D. Estes, and E. Lorenzini, "Overview of future NASA tether applications,"
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2265:(Hans Moravec's thoughts on skyhooks, tethers, rotovators, etc., as of 1987) (accessed 10 October 2010)
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with which the molecules strike as well as their high reactivity. This could quickly erode a tether.
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tether that accurately maintains a set distance between multiple space vehicles flying in formation.
129:, or as part of a planetary-surface-to-orbit / orbit-to-escape-velocity space transportation system.
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Medium close-up view, captured with a 70 mm camera, shows Tethered Satellite System deployment.
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1797:{\displaystyle {\frac {M}{m}}={\sqrt {\pi }}V_{r}\mathrm {e} ^{{V_{r}}^{2}}\mathrm {erf} ({V_{r}})}
373:
255:
195:
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2327:"How an Earth Orbiting Tether Makes Possible an Affordable Earth-Moon Space Transportation System"
1386:
where R is the radius of tether, v is the velocity with respect to the centre, M is the tip mass,
559:
Objects in low Earth orbit are subjected to noticeable erosion from atomic oxygen due to the high
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and orbital plasma dynamics. Five main techniques for employing space tethers are in development:
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1985:
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As mentioned earlier, conductive tethers have failed from unexpected current surges. Unexpected
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The characteristic velocity equals the specific velocity multiplied by the square root of two.
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the system can then re-boost itself with little or no expenditure of consumable reaction mass.
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1956:
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444:. Secondary factors, depending on the application, include cost, strength, and melting point.
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Transactions of the Japan Society for Aeronautical and Space Sciences, Space Technology Japan
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224:, downwards towards the ground, and upwards away, keeping the cable balanced. This is the
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45:, or maintaining the relative positions of the components of a large dispersed satellite/
17:
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Tensile Loading of Ropes of Single-Wall Carbon Nanotubes and their Mechanical Properties
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2303:(Archived copy). Anaheim, CA: International Space Development Conference. Archived from
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This is the use of a (typically) non-conductive tether to connect multiple spacecraft.
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are long cables which can be used for propulsion, momentum exchange, stabilization and
2805:"Space Elevators on Hold at Least Until Stronger Materials Are Available, Experts Say"
2447:
Hypersonic Airplane Space Tether Orbital Launch (HASTOL) System: Interim Study Results
2180:"Lunar Space Elevators for Cislunar Space Development: Phase I Final Technical Report"
1906:
systems mounted on the tether, transmitting their positions to a receiver on the end.
761:
where Ο is the stress limit (in pressure units) and Ο is the density of the material.
30:
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Non-Synchronous Orbital Skyhooks for the Moon and Mars with Conventional Materials -
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58:
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2256:"Non-Synchronous Orbital Skyhooks for the Moon and Mars with Conventional Materials"
579:. Several systems have since been proposed and tested to improve debris resistance:
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1993:
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2934:"Tethers In Space Handbook" M. L. Cosmo and E. C. Lorenzini 3rd ed., December 1997
220:, wrote in greater detail about the idea of a tensile cable to be deployed from a
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In addition the cable shape must be constructed to withstand micrometeorites and
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2618:"Research and Development of Electrodynamic Tethers for Space Debris Mitigation"
2329:. SAE Technical Paper Series (Report). SAE Technical Paper 942120. Vol. 1.
645:
50:
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4222:
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2372:"Hypersonic Airplane Space Tether Orbital Launch System: Phase I Final Report"
1975:
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69:
Tether satellites might be used for various purposes, including research into
46:
2204:"The Journal of the Astronautical Sciences, v25#4, pp. 307β322, OctβDec 1977"
4252:
2121:
Finckenor, Miria; AIAA Technical Committee (December 2005). "Space Tether".
572:
327:
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1921:
have cut tethers (e.g. see Tethered Satellite System Reflight (TSSβ1R) on
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2716:
2524:"A 20-mile long 'spacescraper' dangling from an asteroid: Could it work?"
2021:
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927:
352:
4012:
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2285:, presented at the 1995 AIAA / USU Small Satellite Conference in Logan,
2136:
Bilen, Sven; AIAA Technical Committee (December 2007). "Space Tethers".
190:
Many uses for space tethers have been proposed, including deployment as
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3127:
2007:
495:
Example of a possible layout using the Universal Orbital Support System
441:
267:
57:
is theorized to be significantly less expensive than spaceflight using
2687:
Tensile tests of ropes of very long aligned multiwall carbon nanotubes
3117:
3095:
3009:
2956:
USA National Public Radio β Space Tethers: Slinging Objects in Orbit?
2178:
Pearson, Jerome; Eugene Levin; John Oldson & Harry Wykes (2005).
1922:
1873:
1836:
1823:. This can be achieved with the use of redundant cables, such as the
1068:
915:
660:
474:
289:
166:
92:
3027:
Tethers in Space, a propellantless propulsion in-orbit demonstration
453:
as technology that was to be used to keep the Russian space station
378:
187:
A concept for suspending an object from a tether orbiting in space.
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1933:
Computer models frequently show tethers can snap due to vibration.
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Space elevator equations typically use a "characteristic length",
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243:, and this was found to be possible with materials then existing.
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sensor system. Depending on the mission objectives and altitude,
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Tethered Experiment for Mars inter-Planetary Operations (TEMPOΒ³)
274:
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213:. However, at the time, there was no realistic way to build it.
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3054:
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ESA β Students test 'space postal service' during Foton mission
2616:
Ohkawa, Y.; Kawamoto, S.; Nishida, S. I.; Kitamura, S. (2009).
1406:
is the material density, and T is the design tensile strength.
605:
have also proposed net-based tethers for their future missions.
873:
455:
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An electrodynamic tether was profiled in the documentary film
170:
2740:
Specifications for commercially available PBO (Zylon) cable:
338:
There are many different (and overlapping) types of tether.
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2928:
2433:
E. M. Levin, "Dynamic Analysis of Space Tether Missions",
588:
in operation over 10 years, finally breaking in July 2006.
848:{\displaystyle V_{c}={\sqrt {\frac {2\sigma }{\rho }}}}
2551:. Springer Science & Business Media. p. 163.
2065:
Cosmo, M. L.; Lorenzini, E. C., eds. (December 1998).
894:. Please see the relevant discussion on the article's
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is a proposed 2011 experiment to study the technique.
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2719:, Final Report, May 31, 1996 (accessed 7 April 2011)
598:. Hoytethers have theoretical lifetimes of decades.
382:
A rotating and a tidally stabilized skyhook in orbit
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2039:β theoretical artificial ring placed in Earth orbit
1687:{\displaystyle V_{c}={\sqrt {\frac {2T}{\delta }}}}
198:, and for doing propellant-free orbital transfers.
3046:Video animation explaining how a tether might work
1796:
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1636:
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1375:
861:These values are used in equations similar to the
847:
795:{\displaystyle V={\sqrt {\frac {\sigma }{\rho }}}}
794:
749:
270:, with little loss, or even a net gain of energy.
169:that will be pushed by the momentum of solar wind
2398:H. Moravec, "A non-synchronous orbital skyhook".
571:Simple single-strand tethers are susceptible to
2951:SpaceTethers.com, space tether simulator applet
2768:
2766:
2370:Thomas J. Bogar; et al. (7 January 2000).
2301:An Orbiting Skyhook: Affordable Access to Space
750:{\displaystyle L_{c}={\frac {\sigma }{\rho g}}}
684:more conventional carbon fiber on that scale).
2736:
2734:
2381:. Research Grant No. 07600-018. Archived from
2173:
2171:
2169:
34:Artist's conception of satellite with a tether
4028:
3768:
3066:
2914:ProSEDS, a tether-based propulsion experiment
1161:Honeywell extended chain polyethylene fiber (
386:A skyhook is a theoretical class of orbiting
8:
887:The inclusion of certain items in this list
610:less energy, to dodge known pieces of junk.
254:investigated the physics of non-synchronous
2998:Tether Physics and Survivability Experiment
4377:
4063:
4054:
4035:
4021:
4013:
3775:
3761:
3753:
3518:
3359:
3220:
3073:
3059:
3051:
2717:TSS-1R Mission Failure Investigation Board
2289:, United States (accessed 20 October 2010)
2276:βTethers for Small Satellite Applicationsβ
2060:
2058:
2056:
2054:
2052:
937:
2641:
1784:
1779:
1765:
1757:
1750:
1745:
1743:
1738:
1731:
1720:
1707:
1705:
1667:
1658:
1652:
1633:
1627:
1618:
1606:
1600:
1558:
1552:
1542:
1540:
1525:
1507:
1501:
1491:
1485:
1480:
1466:
1460:
1450:
1445:
1432:
1430:
1391:
1358:
1348:
1342:
1320:
1314:
1304:
1303:
1298:
1280:
1270:
1253:
828:
819:
813:
780:
772:
732:
723:
717:
121:These can be either rotating tethers, or
3485:Atmosphere-breathing electric propulsion
2742:"PBO (Zylon) The high performance fibre"
920:ultra-high-molecular-weight polyethylene
657:ultra-high-molecular-weight polyethylene
2048:
1807:This equation can be compared with the
4233:Differential technological development
2424:, vol. 24, no. 8, pp. 1055β1063, 1999.
2274:Joseph A. Carroll and John C. Oldson,
939:Potential tether / elevator materials
667:. A possible future material would be
531:have a balance of gravitational (e.g.
2400:Journal of the Astronautical Sciences
1880:may cause tether failures or damage.
7:
2668:from the original on 1 February 2016
2503:from the original on 5 February 2013
2402:, vol. 25, no. 4, pp. 307β322, 1977.
2379:NASA Institute for Advanced Concepts
1588:where erf is the normal probability
509:Gravitational gradient stabilization
4322:Future-oriented technology analysis
2606:(see NOSS 2-3, which deployed TiPS)
2534:from the original on 31 March 2017.
2214:from the original on 3 October 2017
342:Momentum exchange tethers, rotating
3390:Field-emission electric propulsion
2946:NASA IAC report on orbital systems
2151:Artsutanov, Yuri (July 31, 1960).
2079:from the original on 29 April 2010
1772:
1769:
1766:
1739:
1532:
1529:
1526:
1481:
1299:
25:
3464:Microwave electrothermal thruster
2879:Mortari, Daniele (January 2008).
2548:Space Tethers and Space Elevators
2472:from the original on 21 June 2012
4376:
3821:
3736:
3010:Tethers Unlimited β’ Publications
2192:from the original on 2016-03-03.
2006:
1992:
1978:
1185:DuPont Aramid fiber (Kevlar 49)
1071:, polybenzoxazole (PBO) fiber ("
1048:(individual molecules measured)
878:
487:Universal Orbital Support System
481:Universal Orbital Support System
183:Universal Orbital Support System
177:Universal Orbital Support System
3022:Tethers in Space Handbook (PDF)
2887:from the original on 2017-10-04
2842:from the original on 2010-11-26
2817:from the original on 2014-03-02
2760:WO2017031482A1 (U.S. Patent #)
2522:Wood, Charlie (29 March 2017).
2341:from the original on 2014-02-22
2325:Sarmont, Eagle (October 1994).
2299:Sarmont, Eagle (May 26, 1990).
1637:{\displaystyle V_{r}=V/V_{c}\,}
165:sail with electrically charged
3594:Pulsed nuclear thermal rocketβ
3490:High Power Electric Propulsion
2929:Tethers Unlimited Incorporated
2435:American Astronautical Society
1791:
1776:
1264:
1258:
631:Properties of useful materials
567:Micrometeorites and space junk
523:Gravity-gradient stabilization
1:
4349:Technology in science fiction
3449:Helicon double-layer thruster
3418:Electrodeless plasma thruster
3413:Magnetoplasmadynamic thruster
2491:Foust, Jeff (July 23, 2001).
1902:on one end of the tether, or
103:, in much the same way as an
4194:Laser communication in space
2493:"Preview: Orphans of Apollo"
2437:, Washington, DC, USA, 2007.
1095:Toray carbon fiber (T1000G)
2976:discusses space tethers on
2573:"TiPS: Missuion Objectives"
2067:"Tethers In Space Handbook"
1889:Pendular motion instability
914:Proposed materials include
639:TSS-1R tether composition
4451:
4420:Vertical transport devices
4354:Technology readiness level
4290:Technological unemployment
3838:Electromagnetic propulsion
2662:science-wired.blogspot.com
2422:Advances in Space Research
1900:inertial navigation system
671:, which have an estimated
552:
520:
484:
466:
406:
371:
345:
315:
216:In 1960, another Russian,
180:
154:
136:
114:
84:
4372:
4337:Technological singularity
4297:Technological convergence
3987:
3819:
3734:
3408:Pulsed inductive thruster
2528:Christian Science Monitor
2153:"V Kosmos na Electrovoze"
681:number of other materials
675:between 140 and 177
585:Naval Research Laboratory
469:Tethered formation flying
283:suborbital launch vehicle
139:Tethered formation flying
133:Tethered formation flying
111:Momentum exchange tethers
18:Tethered satellite system
4199:Orbital propellant depot
4156:Plasma propulsion engine
4151:Nuclear pulse propulsion
3863:Momentum exchange tether
3582:Nuclear pulse propulsion
3341:Electric-pump-fed engine
3241:Hybrid-propellant rocket
3231:Liquid-propellant rocket
2751:(accessed Oct. 20, 2010)
2545:Michel van Pelt (2009).
1919:electrostatic discharges
538:) and centrifugal (e.g.
348:Momentum exchange tether
239:that can go through the
222:geosynchronous satellite
117:Momentum exchange tether
101:planetary magnetic field
4435:Hypothetical technology
4302:Technological evolution
4275:Exploratory engineering
4136:Beam-powered propulsion
4118:Reusable launch vehicle
3638:Beam-powered propulsion
3611:Fission-fragment rocket
3566:Nuclear photonic rocket
3534:Nuclear electric rocket
3300:Staged combustion cycle
3236:Solid-propellant rocket
1937:spinning more strands.
1399:{\displaystyle \delta }
438:electrical conductivity
4312:Technology forecasting
4307:Technological paradigm
4280:Proactionary principle
4081:Non-rocket spacelaunch
3992:Non-rocket spacelaunch
3953:Konstantin Tsiolkovsky
3689:Non-rocket spacelaunch
3539:Nuclear thermal rocket
3439:Pulsed plasma thruster
2961:ESA β The YES2 project
2919:Special Projects Group
2233:Moravec, Hans (1986).
2072:(3rd ed.). NASA.
2032:Non-rocket spacelaunch
2014:Science fiction portal
1798:
1688:
1638:
1579:
1419:
1400:
1377:
965:Characteristic length
849:
796:
751:
640:
518:
504:Technical difficulties
496:
420:, by converting their
414:Electrodynamic tethers
404:
383:
313:
207:Konstantin Tsiolkovsky
81:Electrodynamic tethers
35:
4415:Spacecraft propulsion
4405:Single-stage-to-orbit
4238:Disruptive innovation
4044:Emerging technologies
4002:Megascale engineering
3355:Electrical propulsion
3082:Spacecraft propulsion
2993:New Scientist article
2643:10.2322/tstj.7.Tr_2_5
2628:: Tr_T2_5 β Tr_2_10.
2027:Spacecraft propulsion
1884:Control and modelling
1799:
1689:
1639:
1580:
1417:
1401:
1378:
866:as momentum storage.
850:
797:
752:
638:
553:Further information:
516:
494:
409:Electrodynamic tether
402:
381:
358:electrodynamic tether
318:Space tether missions
311:
87:Electrodynamic tether
55:spacecraft propulsion
33:
4430:Spaceflight concepts
4285:Technological change
4228:Collingridge dilemma
3917:List of competitions
3886:Lunar space elevator
3587:Antimatter-catalyzed
3385:Hall-effect thruster
3198:Solar thermal rocket
2924:NASA tether overview
2160:Komsomolskaya Pravda
2089:See also version of
1904:satellite navigation
1704:
1651:
1599:
1429:
1390:
1252:
812:
771:
716:
143:This is typically a
123:non-rotating tethers
4342:Technology scouting
4317:Accelerating change
4189:Interstellar travel
3529:Direct Fusion Drive
3444:Vacuum arc thruster
3331:Pressure-fed engine
3310:Gas-generator cycle
3217:Chemical propulsion
3154:Physical propulsion
2988:NASA Tether Origami
2983:NASA site on TSS-1R
2971:The Space Show #531
2634:2009TrSpT...7Tr2.5O
2466:"Orphans of Apollo"
940:
889:is currently being
870:Practical materials
374:Skyhook (structure)
127:orbital maneuvering
75:tidal stabilization
53:using this form of
4359:Technology roadmap
3943:Bradley C. Edwards
3743:Spaceflight portal
3709:Reactionless drive
3674:Aerogravity assist
3514:Nuclear propulsion
3015:2006-11-10 at the
3003:2011-07-18 at the
2939:2007-10-06 at the
2866:2007-07-17 at the
2778:2011-05-17 at the
2747:2010-11-15 at the
2692:2011-07-22 at the
2602:2011-09-28 at the
2452:2016-04-27 at the
2281:2011-07-16 at the
2107:2016-04-21 at the
2096:2011-10-27 at the
1986:Spaceflight portal
1872:is difficult in a
1794:
1684:
1634:
1575:
1420:
1396:
1373:
987:Specific velocity
938:
845:
792:
747:
688:conductivity (see
641:
519:
497:
405:
384:
314:
288:In 2000, NASA and
36:
4392:
4391:
4211:
4210:
4207:
4206:
4010:
4009:
3750:
3749:
3704:Atmospheric entry
3659:Orbital mechanics
3626:
3625:
3508:
3507:
3459:Resistojet rocket
3349:
3348:
3324:Intake mechanisms
3257:Liquid propellant
3161:Cold gas thruster
3034:978-90-8891-282-5
2658:"Nanotube Fibers"
2558:978-0-387-76556-3
2235:"Orbital Bridges"
2138:Aerospace America
2123:Aerospace America
1957:center of gravity
1831:Material strength
1725:
1715:
1682:
1681:
1569:
1567:
1550:
1516:
1499:
1477:
1475:
1458:
1440:
1364:
1329:
1312:
1295:
1224:
1223:
1205:Silicon carbide
1118:(planned values)
912:
911:
843:
842:
790:
789:
745:
601:Researchers with
450:Orphans of Apollo
426:electrical energy
388:tether propulsion
252:Robert L. Forward
71:tether propulsion
16:(Redirected from
4442:
4380:
4379:
4327:Horizon scanning
4243:Ephemeralization
4161:Helicon thruster
4146:Laser propulsion
4064:
4055:
4037:
4030:
4023:
4014:
3969:KC Space Pirates
3874:Related concepts
3825:
3777:
3770:
3763:
3754:
3740:
3724:Alcubierre drive
3714:Field propulsion
3664:Orbital maneuver
3652:Related concepts
3519:
3370:Colloid thruster
3360:
3221:
3123:Specific impulse
3075:
3068:
3061:
3052:
2897:
2895:
2893:
2892:
2876:
2870:
2858:
2852:
2850:
2848:
2847:
2832:
2826:
2825:
2823:
2822:
2800:
2794:
2788:
2782:
2770:
2761:
2758:
2752:
2738:
2729:
2726:
2720:
2713:
2707:
2702:
2696:
2684:
2678:
2677:
2675:
2673:
2654:
2648:
2647:
2645:
2613:
2607:
2597:NOSS Launch Data
2594:
2588:
2587:
2585:
2584:
2575:. Archived from
2569:
2563:
2562:
2542:
2536:
2535:
2519:
2513:
2512:
2510:
2508:
2497:The Space Review
2488:
2482:
2481:
2479:
2477:
2462:
2456:
2444:
2438:
2431:
2425:
2418:
2412:
2409:
2403:
2396:
2390:
2389:
2388:on 24 July 2011.
2387:
2376:
2367:
2361:
2356:
2350:
2349:
2347:
2346:
2322:
2316:
2315:
2313:
2312:
2296:
2290:
2272:
2266:
2252:
2246:
2245:
2243:
2241:
2230:
2224:
2223:
2221:
2219:
2200:
2194:
2193:
2191:
2184:
2175:
2164:
2163:
2157:
2148:
2142:
2141:
2133:
2127:
2126:
2118:
2112:
2088:
2086:
2084:
2078:
2071:
2062:
2016:
2011:
2010:
2002:
1997:
1996:
1988:
1983:
1982:
1981:
1803:
1801:
1800:
1795:
1790:
1789:
1788:
1775:
1764:
1763:
1762:
1761:
1756:
1755:
1754:
1742:
1736:
1735:
1726:
1721:
1716:
1708:
1693:
1691:
1690:
1685:
1683:
1677:
1669:
1668:
1663:
1662:
1643:
1641:
1640:
1635:
1632:
1631:
1622:
1611:
1610:
1584:
1582:
1581:
1576:
1574:
1570:
1568:
1563:
1562:
1553:
1551:
1543:
1541:
1535:
1524:
1523:
1522:
1518:
1517:
1512:
1511:
1502:
1500:
1492:
1484:
1478:
1476:
1471:
1470:
1461:
1459:
1451:
1446:
1441:
1433:
1405:
1403:
1402:
1397:
1382:
1380:
1379:
1374:
1372:
1371:
1370:
1366:
1365:
1363:
1362:
1353:
1352:
1343:
1330:
1325:
1324:
1315:
1313:
1305:
1302:
1296:
1294:
1286:
1285:
1284:
1271:
1046:carbon nanotubes
1037:
1036:
1009:
1008:
941:
924:carbon nanotubes
907:
904:
882:
881:
874:
854:
852:
851:
846:
844:
838:
830:
829:
824:
823:
801:
799:
798:
793:
791:
782:
781:
756:
754:
753:
748:
746:
744:
733:
728:
727:
673:tensile strength
669:carbon nanotubes
463:Formation flying
324:tether satellite
241:L1 and L2 points
43:attitude control
21:
4450:
4449:
4445:
4444:
4443:
4441:
4440:
4439:
4395:
4394:
4393:
4388:
4368:
4203:
4177:
4122:
4046:
4041:
4011:
4006:
3983:
3957:
3938:Yuri Artsutanov
3926:
3905:
3869:
3848:Carbon nanotube
3826:
3817:
3786:
3781:
3751:
3746:
3730:
3647:
3622:
3570:
3504:
3473:
3427:
3401:Electromagnetic
3396:
3345:
3336:Pump-fed engine
3319:
3288:
3245:
3212:
3149:
3140:Rocket equation
3106:Reaction engine
3084:
3079:
3042:
3017:Wayback Machine
3005:Wayback Machine
2941:Wayback Machine
2910:
2905:
2900:
2890:
2888:
2878:
2877:
2873:
2868:Wayback Machine
2861:Tether dynamics
2859:
2855:
2845:
2843:
2834:
2833:
2829:
2820:
2818:
2813:. 29 May 2013.
2803:
2801:
2797:
2789:
2785:
2780:Wayback Machine
2771:
2764:
2759:
2755:
2749:Wayback Machine
2739:
2732:
2727:
2723:
2714:
2710:
2703:
2699:
2694:Wayback Machine
2685:
2681:
2671:
2669:
2656:
2655:
2651:
2615:
2614:
2610:
2604:Wayback Machine
2595:
2591:
2582:
2580:
2579:on July 8, 2007
2571:
2570:
2566:
2559:
2544:
2543:
2539:
2521:
2520:
2516:
2506:
2504:
2490:
2489:
2485:
2475:
2473:
2468:. World Press.
2464:
2463:
2459:
2454:Wayback Machine
2445:
2441:
2432:
2428:
2419:
2415:
2410:
2406:
2397:
2393:
2385:
2374:
2369:
2368:
2364:
2357:
2353:
2344:
2342:
2324:
2323:
2319:
2310:
2308:
2298:
2297:
2293:
2283:Wayback Machine
2273:
2269:
2253:
2249:
2239:
2237:
2232:
2231:
2227:
2217:
2215:
2202:
2201:
2197:
2189:
2182:
2177:
2176:
2167:
2155:
2150:
2149:
2145:
2135:
2134:
2130:
2120:
2119:
2115:
2109:Wayback Machine
2100:; available on
2098:Wayback Machine
2082:
2080:
2076:
2069:
2064:
2063:
2050:
2046:
2012:
2005:
1998:
1991:
1984:
1979:
1977:
1974:
1949:
1931:
1915:
1891:
1886:
1866:
1864:Life expectancy
1857:
1833:
1817:
1809:rocket equation
1780:
1746:
1744:
1737:
1727:
1702:
1701:
1670:
1654:
1649:
1648:
1623:
1602:
1597:
1596:
1554:
1536:
1503:
1490:
1486:
1479:
1462:
1427:
1426:
1412:
1388:
1387:
1354:
1344:
1335:
1331:
1316:
1297:
1287:
1276:
1272:
1250:
1249:
1243:
1234:
1229:
1038:
1027:
1025:
1023:
1015:
1014:Char. velocity
1010:
1000:
998:
996:
988:
983:
974:
966:
961:
957:
952:
948:
908:
902:
899:
883:
879:
872:
863:rocket equation
831:
815:
810:
809:
769:
768:
737:
719:
714:
713:
709:gravity field.
704:
633:
628:
620:Van Allen belts
616:
573:micrometeoroids
569:
557:
551:
544:
537:
525:
511:
506:
489:
483:
471:
465:
411:
397:
395:Electrodynamics
376:
370:
350:
344:
336:
320:
306:
218:Yuri Artsutanov
204:
192:space elevators
185:
159:
141:
119:
89:
67:
65:Main techniques
28:
23:
22:
15:
12:
11:
5:
4448:
4446:
4438:
4437:
4432:
4427:
4422:
4417:
4412:
4410:Space elevator
4407:
4397:
4396:
4390:
4389:
4387:
4386:
4373:
4370:
4369:
4367:
4366:
4361:
4356:
4351:
4346:
4345:
4344:
4339:
4334:
4329:
4324:
4319:
4309:
4304:
4299:
4294:
4293:
4292:
4282:
4277:
4272:
4271:
4270:
4265:
4260:
4255:
4245:
4240:
4235:
4230:
4225:
4219:
4217:
4213:
4212:
4209:
4208:
4205:
4204:
4202:
4201:
4196:
4191:
4185:
4183:
4179:
4178:
4176:
4175:
4170:
4169:
4168:
4163:
4153:
4148:
4143:
4138:
4132:
4130:
4124:
4123:
4121:
4120:
4115:
4114:
4113:
4108:
4106:Space fountain
4103:
4101:Space elevator
4098:
4093:
4088:
4078:
4072:
4070:
4061:
4052:
4048:
4047:
4042:
4040:
4039:
4032:
4025:
4017:
4008:
4007:
4005:
4004:
3999:
3994:
3988:
3985:
3984:
3982:
3981:
3979:LiftPort Group
3976:
3971:
3965:
3963:
3959:
3958:
3956:
3955:
3950:
3948:Jerome Pearson
3945:
3940:
3934:
3932:
3928:
3927:
3925:
3924:
3919:
3913:
3911:
3907:
3906:
3904:
3903:
3901:Space fountain
3898:
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3888:
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3871:
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3865:
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3853:Nanotechnology
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3820:
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3784:Space elevator
3782:
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3669:Gravity assist
3666:
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3640:
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3631:External power
3628:
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3618:
3608:
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3604:Bussard ramjet
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3432:Electrothermal
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3307:
3305:Expander cycle
3302:
3296:
3294:
3290:
3289:
3287:
3286:
3281:
3276:
3274:Monopropellant
3271:
3270:
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3253:
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3184:
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3168:
3163:
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3150:
3148:
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3145:Thermal rocket
3142:
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3125:
3115:
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3113:
3108:
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3019:
3007:
2995:
2990:
2985:
2980:
2978:the Space Show
2974:Robert P. Hoyt
2968:
2963:
2958:
2953:
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2903:External links
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2335:10.4271/942120
2317:
2291:
2267:
2261:1999-10-12 at
2254:Hans Moravec,
2247:
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2018:
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2003:
2000:Science portal
1989:
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1970:
1953:center of mass
1948:
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1590:error function
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592:Robert P. Hoyt
589:
568:
565:
550:
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535:
521:Main article:
510:
507:
505:
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485:Main article:
482:
479:
467:Main article:
464:
461:
422:kinetic energy
407:Main article:
396:
393:
372:Main article:
369:
366:
362:ion propulsion
360:thrusting, or
346:Main article:
343:
340:
335:
332:
316:Main article:
305:
302:
237:lunar elevator
233:Jerome Pearson
231:In the 1970s,
226:space elevator
203:
200:
181:Main article:
179:
178:
155:Main article:
153:
152:
145:non-conductive
137:Main article:
135:
134:
115:Main article:
113:
112:
105:electric motor
85:Main article:
83:
82:
66:
63:
59:rocket engines
27:Type of tether
26:
24:
14:
13:
10:
9:
6:
4:
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2:
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4364:Transhumanism
4362:
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4084:
4083:
4082:
4079:
4077:
4076:Fusion rocket
4074:
4073:
4071:
4069:
4065:
4062:
4060:
4059:Space science
4056:
4053:
4049:
4045:
4038:
4033:
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4026:
4024:
4019:
4018:
4015:
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3993:
3990:
3989:
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3975:
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3970:
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3964:
3962:Organizations
3960:
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3935:
3933:
3929:
3923:
3922:Elevator:2010
3920:
3918:
3915:
3914:
3912:
3908:
3902:
3899:
3897:
3894:
3892:
3889:
3887:
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3872:
3864:
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3859:
3856:
3854:
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3846:
3844:
3843:Counterweight
3841:
3839:
3836:
3835:
3833:
3829:
3824:
3814:
3811:
3809:
3806:
3804:
3801:
3799:
3796:
3795:
3793:
3791:Main articles
3789:
3785:
3778:
3773:
3771:
3766:
3764:
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3755:
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3707:
3705:
3702:
3700:
3697:
3695:
3692:
3690:
3687:
3685:
3682:
3680:
3679:Oberth effect
3677:
3675:
3672:
3670:
3667:
3665:
3662:
3660:
3657:
3656:
3654:
3650:
3644:
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3635:
3633:
3629:
3617:
3614:
3613:
3612:
3609:
3605:
3602:
3601:
3600:
3599:Fusion rocket
3597:
3595:
3592:
3588:
3585:
3584:
3583:
3580:
3579:
3577:
3573:
3567:
3564:
3560:
3557:
3555:
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3550:
3547:
3545:
3542:
3541:
3540:
3537:
3535:
3532:
3530:
3527:
3526:
3524:
3522:Closed system
3520:
3517:
3515:
3511:
3501:
3498:
3496:
3493:
3491:
3488:
3486:
3483:
3482:
3480:
3476:
3470:
3467:
3465:
3462:
3460:
3457:
3455:
3454:Arcjet rocket
3452:
3450:
3447:
3445:
3442:
3440:
3437:
3436:
3434:
3430:
3424:
3423:Plasma magnet
3421:
3419:
3416:
3414:
3411:
3409:
3406:
3405:
3403:
3399:
3391:
3388:
3386:
3383:
3381:
3378:
3377:
3376:
3373:
3371:
3368:
3367:
3365:
3363:Electrostatic
3361:
3358:
3356:
3352:
3342:
3339:
3337:
3334:
3332:
3329:
3328:
3326:
3322:
3316:
3315:Tap-off cycle
3313:
3311:
3308:
3306:
3303:
3301:
3298:
3297:
3295:
3291:
3285:
3284:Tripropellant
3282:
3280:
3277:
3275:
3272:
3268:
3265:
3263:
3260:
3259:
3258:
3255:
3254:
3252:
3248:
3242:
3239:
3237:
3234:
3232:
3229:
3228:
3226:
3222:
3219:
3215:
3209:
3206:
3204:
3203:Photon rocket
3201:
3199:
3196:
3194:
3193:Magnetic sail
3191:
3189:
3188:Electric sail
3186:
3182:
3179:
3178:
3177:
3174:
3172:
3169:
3167:
3164:
3162:
3159:
3158:
3156:
3152:
3146:
3143:
3141:
3138:
3136:
3133:
3129:
3126:
3124:
3121:
3120:
3119:
3116:
3112:
3111:Reaction mass
3109:
3107:
3104:
3103:
3102:
3101:Rocket engine
3099:
3097:
3094:
3093:
3091:
3087:
3083:
3076:
3071:
3069:
3064:
3062:
3057:
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2515:
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2498:
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2328:
2321:
2318:
2307:on 2014-02-22
2306:
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2271:
2268:
2264:
2263:archive.today
2260:
2257:
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2213:
2209:
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2199:
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2172:
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2166:
2162:(in Russian).
2161:
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2020:
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2015:
2009:
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2001:
1995:
1990:
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1961:
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1954:
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1934:
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1855:Cargo capture
1854:
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1007:
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956:Stress limit
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708:
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696:
693:
691:
685:
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678:
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662:
658:
653:
651:
650:atomic oxygen
647:
637:
630:
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623:
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604:
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597:
593:
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586:
582:
581:
580:
578:
574:
566:
564:
562:
561:orbital speed
556:
555:Atomic oxygen
549:Atomic oxygen
548:
546:
541:
534:
528:
524:
515:
508:
503:
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493:
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157:Electric sail
151:Electric sail
150:
149:
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110:
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72:
64:
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60:
56:
52:
48:
44:
40:
39:Space tethers
32:
19:
4381:
4268:Robot ethics
4141:Ion thruster
4111:Space tether
4110:
4091:Orbital ring
3910:Competitions
3891:Orbital ring
3858:Space tether
3857:
3831:Technologies
3798:Construction
3741:
3684:Space launch
3642:
3616:Fission sail
3544:Radioisotope
3375:Ion thruster
3293:Power cycles
3279:Bipropellant
3171:Steam rocket
3166:Water rocket
2889:. Retrieved
2874:
2856:
2844:. Retrieved
2830:
2819:. Retrieved
2808:
2798:
2792:Hans Moravec
2786:
2756:
2724:
2711:
2700:
2682:
2670:. Retrieved
2661:
2652:
2625:
2621:
2611:
2592:
2581:. Retrieved
2577:the original
2567:
2547:
2540:
2527:
2517:
2505:. Retrieved
2496:
2486:
2474:. Retrieved
2460:
2442:
2434:
2429:
2421:
2416:
2407:
2399:
2394:
2383:the original
2365:
2354:
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2320:
2309:. Retrieved
2305:the original
2294:
2270:
2250:
2238:. Retrieved
2228:
2216:. Retrieved
2207:
2198:
2159:
2146:
2137:
2131:
2122:
2116:
2081:. Retrieved
2037:Orbital ring
1962:
1950:
1947:Other issues
1942:
1939:
1935:
1932:
1916:
1908:
1896:
1892:
1867:
1858:
1834:
1824:
1818:
1806:
1696:
1594:
1587:
1421:
1385:
1244:
1235:
1044:Single-wall
1033:
1029:
1020:
1016:
1005:
1001:
993:
989:
980:
976:
971:
967:
958:
949:
913:
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888:
860:
857:
804:
763:
760:
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665:carbon fiber
654:
642:
626:Construction
617:
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570:
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279:
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248:Hans Moravec
245:
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189:
186:
160:
142:
120:
90:
68:
38:
37:
4332:Moore's law
4263:Neuroethics
4258:Cyberethics
4086:Mass driver
3997:Spaceflight
3974:LaserMotive
3881:Launch loop
3699:Aerocapture
3694:Aerobraking
3575:Open system
3559:"Lightbulb"
3500:Mass driver
3250:Propellants
3181:Diffractive
2728:Bacon 2005.
1878:overheating
1141:(existing)
51:spaceflight
4425:Satellites
4399:Categories
4223:Automation
4173:Solar sail
4128:Propulsion
3813:In fiction
3719:Warp drive
3549:Salt-water
3267:Hypergolic
3176:Solar sail
2891:2017-11-01
2846:2011-03-26
2821:2014-04-06
2583:2011-10-06
2507:30 January
2476:30 January
2345:2014-02-09
2311:2014-02-09
2240:January 8,
2083:20 October
2044:References
1929:Vibrations
1870:waste heat
1849:hypersonic
1845:supersonic
1821:space junk
1815:Redundancy
1410:Mass ratio
903:April 2014
577:space junk
459:in orbit.
418:generators
266:and other
250:and later
163:solar wind
161:A form of
47:spacecraft
4253:Bioethics
3803:Economics
3262:Cryogenic
2091:NASA MSFC
1860:however.
1825:Hoytether
1723:π
1679:δ
1545:δ
1494:δ
1453:δ
1448:π
1394:δ
1340:−
1307:δ
1241:Thickness
944:Material
896:talk page
840:ρ
836:σ
787:ρ
784:σ
739:ρ
735:σ
614:Radiation
596:Hoytether
434:conductor
328:satellite
273:In 1979,
246:In 1977,
3554:Gas core
3089:Concepts
3013:Archived
3001:Archived
2937:Archived
2885:Archived
2864:Archived
2840:Archived
2815:Archived
2810:HuffPost
2776:Archived
2745:Archived
2690:Archived
2666:Archived
2600:Archived
2532:Archived
2501:Archived
2470:Archived
2450:Archived
2339:Archived
2279:Archived
2259:Archived
2212:Archived
2187:Archived
2105:Archived
2094:Archived
2074:Archived
2022:STARS-II
1972:See also
1232:Tapering
1139:M5 fiber
1116:M5 fiber
947:Density
928:M5 fiber
891:disputed
440:and low
428:, or as
353:Momentum
304:Missions
256:skyhooks
196:skyhooks
4096:Skyhook
3896:Skyhook
3643:Tethers
3495:MagBeam
3380:Gridded
3135:Staging
3128:Delta-v
2630:Bibcode
2208:cmu.edu
1841:Spectra
1163:Spectra
1039:(km/s)
1026:√
1011:(km/s)
999:√
953:(kg/m)
583:The US
442:density
368:Skyhook
268:planets
202:History
167:tethers
99:from a
4248:Ethics
4216:Topics
4166:VASIMR
4068:Launch
4051:Fields
3931:People
3808:Safety
3469:VASIMR
3118:Thrust
3096:Rocket
3032:
2715:NASA,
2555:
2102:Scribd
1923:STSβ75
1913:Surges
1874:vacuum
1837:Kevlar
1697:then:
1208:3,000
1188:1,440
1165:2000)
1144:1,700
1121:1,700
1098:1,810
1078:1,340
1069:Aramid
1057:2,200
1051:2,266
962:(GPa)
916:Kevlar
661:aramid
430:motors
294:HASTOL
290:Boeing
107:does.
93:thrust
4182:Other
3478:Other
3224:State
3040:Video
2672:3 May
2386:(PDF)
2375:(PDF)
2218:3 May
2190:(PDF)
2183:(PDF)
2156:(PDF)
2140:: 89.
2125:: 78.
2077:(PDF)
2070:(PDF)
1965:bolus
1963:With
1876:, so
1227:Shape
1073:Zylon
984:(km)
932:lunar
334:Types
326:is a
298:orbit
211:Earth
194:, as
4383:List
3208:WINE
3030:ISBN
2908:Text
2674:2018
2553:ISBN
2509:2013
2478:2013
2287:Utah
2242:2023
2220:2018
2085:2010
1955:and
1847:(or
1839:and
1595:Let
1220:2.0
1217:1.4
1214:199
1211:5.9
1200:2.2
1197:1.6
1194:255
1191:3.6
1180:2.5
1177:1.8
1174:316
1171:3.0
1168:970
1156:2.6
1153:1.8
1150:340
1147:5.7
1133:3.3
1130:2.4
1127:570
1124:9.5
1110:2.7
1107:1.9
1104:360
1101:6.4
1090:3.0
1087:2.1
1084:450
1081:5.9
1063:6.6
1060:4.7
926:and
648:and
603:JAXA
575:and
275:NASA
264:Mars
260:Moon
171:ions
97:drag
2638:doi
2331:doi
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1054:50
898:.
692:).
690:EDT
677:GPa
663:or
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456:Mir
424:to
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