Rocky IV. This vehicle, designed by NASA's Jet Propulsion Laboratory, is a prototype for a future planetary exploration rover. Rocky IV is a miniature version of its predecessor Rocky III; it is just 61cm long, 36cm high and weighs 7.5kg. Despite this, Rocky IV carries a colour video camera, a soil sampling scoop and a 'chipper' at the front to expose fresh surfaces of rocks. Additional tasks may include placing of seismometers and other instruments at various surface locations. Each of the six wheels is driven by its own electric motor, and the chassis uses a 'rocker-bogey' springless suspension. The first likely target for such a vehicle is Mars.