When engineers at NASA's Jet Propulsion Laboratory (JPL) were given the job of sending another rover to Mars, they knew they faced a sizeable challenge. The NASA rover mission launched in 2003, for example, involved the twin golf-cart sized (5 ft/1.6m long) Mars Exploration Rovers, Spirit and Opportunity. Each weighed a mere 185 lb/84 kg. The proposed mission, however, would require a rover the size of a mini-compact car - about five times as heavy and twice as long (1,984 lb/900 kg and 10 ft/3m long).
展开▼
