Rim Blow $37. A rubber pad encasing wires was mounted around the entire inner surface of the steering wheel rim. Rather than pressing a suspended horn ring, a center horn pad, or switches on the spokes, to make the electrical contact, the inside of the rim could be pressed anywhere on its circumference. Applying pressure to soft rubber inner rim of the steering wheel, a driver could activate the car's horn without moving their hands from the wheel rims. Technical issues, such as hardening (difficult to activate) and shrinking (causing the horn to sound without activation) of the rubber, and a lack
Reaction wheel temporary changes in its speed result in small changes in angle. The wheels therefore permit very precise changes in a spacecraft's attitude. For this reason, reaction wheels are often used to aim spacecraft carrying cameras or telescopes. Over time, reaction wheels may build up enough stored momentum to exceed the maximum speed of the wheel, called saturation, which will need to be cancelled. Designers therefore supplement reaction wheel systems with other attitude control mechanisms. In the presence of a magnetic field (as in low Earth orbit), a spacecraft can employ magnetorquers (better known as torque rods) to transfer angular momentum