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SUMMARY:The Tether Solution - Jonathan Edge ( TCM)
DTSTART:20081107T143000Z
DTEND:20081107T150000Z
UID:TALK15022@talks.cam.ac.uk
CONTACT:Daniel Cole
DESCRIPTION:L. Johnson\, "IEEE Spectrum 37\, 38 (2000) ":http://ieeexplore
 .ieee.org/xpls/abs_all.jsp?arnumber=852050\n\nCurrent-carrying wire tether
 s are promising a cheap and reliable means and propelling spacecraft. The 
 electrodynamic tether is a current-carrying wire that harnesses the force 
 exerted by Earth's magnetic field. The propellant-free device could one da
 y have several uses: to transfer working satellites to new orbits\; remove
  defunct satellites from orbit\; keep the International Space Station alof
 t\, and even power missions to the outer planets. The technology may also 
 be used aboard the Russians' Mir space station. An important test of the e
 lectrodynamic tether will take place in December 2000. NASA's US $7 millio
 n Propulsive Small Expendable Deployer System (ProSEDS) experiment will sh
 ow that an 11 kg\, 5 km-long\, 1.2 mm-diameter aluminum wire can rapidly r
 emove a rocket's upper stage from orbit. The author describes basic princi
 ples of electrodynamic tether thrusters. The Earth's magnetic field exerts
  a force on and accelerates the wire and hence any payload attached to it.
  The direction of current flow through the tether\, either away or towards
  the Earth\, determines whether the magnetic force will add to or subtract
  from the tether's orbital energy\, and therefore raise or lower its orbit
 .
LOCATION:TCM Seminar Room\, Cavendish Laboratory
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