INTRODUCTION:

Electrodynamic tethers are long, thin conductive cables stationed in space that can be used to induce power by removing kinetic energy from their orbital stir, or to produce thrust when adding energy from an on- board source. In either case, the frictional or thrust force, is produced electrodynamically, through the commerce between moving charges and glamorous fields. From then, we notice that the operation of electrodynamic tethers is confined to elysian objects that have anon-zero glamorous field and ionospheric tube (e.g., Earth, Jupiter, Saturn, etc, not the moon or Mercury, etc).

APPLICATIONS:

* Charged tethers can be used to scatter radiation belt patches into a pitch angle loss cone, leading to the immersion of the patches in the atmosphere.

* Single to multiple EDT systems can be used tode-orbit satellites by generating a Lorentz force drag

* EDT systems can be used to convert kinetic energy into electric energy.

* Short to medium EDTs can use solar power to push against a planetary glamorous field to achievepropellant-less propulsion.

* Momentum Exchange TetherRe-boosting using EDTs works also to SatelliteRe-boosting using EDTs. The crucial difference is the difference in scale and complexity.

ADVANTAGES:

* The functional advantages of electrodynamic tethers of moderate length are getting apparent from studies of collision avoidance. Although long tethers (of order of 10 kilometers) give high effectiveness and good rigidity to varying tube conditions, boosting tethers of moderate length (

1kilometer) and suitable design might still operate at respectable edge and acceptable rigidity to a changing terrain.

* ED tethers used for propulsion in low- Earth route and hereafter could significantly reduce the weight of upper stages used to boost spacecraft to advanced route. Important of the w eight of any launch

vehicle is the fuel and It’s precious to lift heavy forces off the ground.

* Since ED tethers bear no fuel, they could mainly reduce the weight of the spacecraft and give a cost effective system of re-boosting spacecraft, similar as the International Space Station

DISADVANTAGES:

Despite all their benefits, EDTs have two critical limitations they’re fluently disassociated by the impact of micro-debris and are subject to power surges and climate in the tether. It’s nearly insolvable using current technology to repair an EDT once the tether is disassociated. The stylish presently available mitigation strategy is to have spare current paths to make up in the event of a string failure and to upgrade electronics and other factors of the EDT to more repel power surges and electrostatic discharges (Sobel and Barcelo, 2007). Two other aspects that largely determine the complexity of using EDTs are icing contact of the tether with the ionosphere and determining the inclination of the route.

CONCLUSION:

Tether technology has advanced significantly since its commencement over 30 times agone. The recent successes of the SEDS system shows that tethers are ready to move from trial and demonstration to operation. One of the most promising operations for tethers is space propulsion. The use of electrodynamic tether propulsion for applicable upper stages, planetary operations, space station, and launch vehicle deorbit operations will soon be demonstrated with the ProSEDS trial.