Jess (falconry) anklet worn by the bird, which is itself formed of another rectangular strip of leather, bound together at the ends by a grommet (usually of brass), prevented from slipping through the grommet by the knobbed end. Often, another slit is placed near the thin end of the jess cut about one inch long and running lengthwise, through which a special type of swivel is fitted, preventing the whole arrangement from twisting or tangling about itself or the bird when a leash is threaded through the other end. Their intent is more to prevent the risk of the bird deciding to
Momentum exchange tether field such as around the Earth, a conducting tether can be configured as an electrodynamic tether. This can either be used as a dynamo to generate power for the satellite at the cost of slowing its orbital velocity, or it can be used to increase the orbital velocity of the satellite by putting power into the tether from the satellite's power system. Thus the tether can be used to either accelerate or to slow an orbiting spacecraft without using any rocket propellant. When using this techniques with a rotating tether, the current through the tether must alternate in phase with