TETHERS
Although this complex process has not yet been proven, removal of a large-mass piece of orbital debris
might be achieved by using tethers. A conductive tether—also known as an electrodynamic tether—is a
long conducting wire that generates electric potential by its motion through the Earth’s magnetic field. Such
a tether could be attached to the targeted piece of orbital debris. The current generated by the tether would
produce a charge that de-orbits the object, causing it to reenter the Earth’s atmosphere more quickly than if
it had stayed on-orbit. While this procedure could be effective for de-orbiting large objects in LEO, it would
be complex and costly to use.
Momentum tethers might provide another means of de-orbiting a large object. In this scenario, a nonconductive
tether is attached to the piece of orbital debris. The tether is first swung back and forth to
generate
momentum, then severed.
Once the tether is cut, the resulting
momentum swings the object out
of
orbit. Like conductive tethers, momentum tethers might effectively
de-orbit large
masses; but they,
too,
would be complex and costly to use.