ABOUT ELECTRODYNAMIC TETHER, ITS STABILIZATION, ITS ADVANTAGES. In an “electrodynamic tether drag” system, such as the Terminator Tether, the tether can be used to reduce the orbit of the spacecraft to which it is attached. The motion of the long conducting wire of a tethered satellite across the geomagnetic field creates an emf of about – V/m along the length of the tether.

Author: Faekazahn Dobei
Country: Iceland
Language: English (Spanish)
Genre: Music
Published (Last): 11 July 2011
Pages: 277
PDF File Size: 18.32 Mb
ePub File Size: 10.81 Mb
ISBN: 587-6-90213-289-7
Downloads: 17610
Price: Free* [*Free Regsitration Required]
Uploader: Arami

The load on the current may take the form of a charging device which, in turn, charges reserve power sources such as batteries. Some important parameters include plasma density, electron and ion temperature, ion molecular weight, magnetic field strength and orbital velocity relative to the surrounding plasma. In addition, the geometry affects the emission of the plasma from the HC as seen in the below figure.

Rosen derived the equation that is now known as the OML theory of dust charging. This theory accounts for and conserves particle energy and angular momentum.

There was a problem providing the content you requested

However, it is more difficult for the opposite negative end of the tether to eject free electrons or to collect positive ions from electrodynaimc plasma.

In this case electrical power supplied by a set of solar arrays is used to run a current through the tether. This diagram shows that, from point A of the tether down to point Bthere is a positive potential bias, which increases the collected current. To facilitate the collection of electrons, the anode can be a large metal sphere.

Any exposed conducting section of the EDT system can passively ‘passive’ and ‘active’ emission refers to the use of pre-stored energy in order to achieve the desired effect collect electron or ion current, depending on the electric potential of the spacecraft body with respect to the ambient plasma. However, this has been found to be ineffective. In-plane and out-of-plane direction is determined by the orbital velocity vector of the system.


For this derivation, it is assumed that the magnetic field lines are all the same angle throughout the length of the tether, and that the tether is rigid. This “electrodynamic drag force” will decrease the orbit of the tether and its host spacecraft.

The second use of EDT is really amazing. It uses the Earth’s magnetic field as its “reaction mass. Bill Christensen catalogues the inventions, technology and ideas of science fiction writers at his website, Technovelgy.

Electrodynamic Tethers: Getting into the Swing

An early experiment used a meter conducting electrodyanmic. Work has been accomplished on current collection using porous spheres, by Stone et al. Since it takes a much greater potential difference to collect an equivalent amount of ion current for a given areaelectrodyynamic total current in the tether is reduced by a smaller amount.

If the system has a means for collecting electrons from the conducting ionospheric plasma at one end of the tether and expelling them back into the plasma at the other end of the tether, the motional EMF voltage will drive a current along the tether. If the tether geometry is a flat tape, then an approximation can be electrodunamic to convert the normalized tape width to an equivalent cylinder radius. This assessment follows analysis by a joint U. An Ariadna study was conducted on the concept of using an electrodynamic tether to explore Jupiter with microsatellites.

Set it up so the force opposes motion and the craft loses energy and descends.

An electrodynamic tether is attached to an object, the tether being oriented at an angle to the local vertical between the object and a planet with a magnetic field. Deployment, Experiments and Retrieval.

The 13 day, hour space flight will begin when the Space Shuttle Orbiter Columbia lifts off from Launch Pad 39B and climbs to a statute-mile-high orbit with a The satellite carries an additional four instruments. In reverse the EDT system could be used for acceleration. These effects pertain to all conducting surfaces on an EDT system, not just the end-body.

Electrodynamic Tethers: Getting into the Swing

These investigations will help us understand things such as the behavior of comet tails and the radio “noise” emitted by Jupiter. The board concluded that after arcing had burned through most of the Kevlar, the few remaining strands were not enough to withstand forces being exerted by satellite deployment Here’s the deal, if you can summarise the slowing down part in 20 words, I will delete my pathetic effort.


It is plausible that, by using a very large collection area at one end of the tether, enough ions can be collected to permit significant current through the plasma. Here, the ProSEDS de-boost tether system is configured to enable electron collection to the positively biased higher altitude section of the bare tether, and returned to the ionosphere at the lower altitude end.

Also, by exploring the dynamics of yether systems, we may develop a variety of possible applications, tetheg as generating electrical power or propulsion for future spacecraft. The B direction changes as the tether orbits the Earth, and thus the direction and magnitude of the ED forces also change.

Then there is active collection and emission techniques involved in an EDT system. Elctrodynamic, the technology is touted as a promising candidate to deorbit space debris at low cost. He is a contributor to Live Science and Space. Incidentally, the tether continued arcing long after it and its satellite were drifting free, until finally it went into night conditions where the electron density was insufficient to sustain the arc.

Pegasus Research Consortium distributes this material without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.

The characteristics of the TSS which are related to high voltages, electrical currents, energy storage, power, and the generation of plasma waves are described.