Leather part for their skins. Kangaroo leather is used to make items that must be strong and flexible. It is the material most commonly used in bullwhips. Some motorcyclists favor kangaroo leather for motorcycle leathers because of its light weight and abrasion resistance. Kangaroo leather is also used for falconry jesses, soccer footwear, and boxing speed bags. Although originally raised for their feathers in the 19th century, ostriches are now more popular for both meat and leather. Ostrich leather has a characteristic "goose bump" look because of the large follicles where the feathers grew. Different processes produce different finishes for many
Space tether generated across a conductive tether by its motion through the earth's magnetic field. The choice of the metal conductor to be used in an electrodynamic tether is determined by a variety of factors. Primary factors usually include high electrical conductivity and low density. Secondary factors, depending on the application, include cost, strength, and melting point. An electrodynamic tether was profiled in the documentary film "Orphans of Apollo" as technology that was to be used to keep the Russian space station "Mir" in orbit. This is the use of a (typically) non-conductive tether to connect multiple spacecraft. A proposed 2011 experiment