Jess (falconry) the bird, but the width is proportional to leg-length. Traditional jesses are made from a single length of leather, and slits are placed strategically along the jess to allow it to be looped through itself and around the ankle of the bird so that it fits comfortably but securely about and just above what would be the bird's ankle. With Aylmeri jesses, as created by Major Guy Aylmeri, the end of the jess is instead looped through itself repeatedly to form a "button", or knob at one end. The thin, pliable end of the jess is then threaded through an
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