<DIV>Is there life on Mars? This age-old question has prompted many missions to Mars, with the most recent rover, Curiosity, having safely landed in August 2012 amid a blaze of publicity. This manual covers the development, design and engineering of three generations of Mars rover: Sojourner, which landed in 1997, was the size of a microwave; Spirit and Opportunity, both the size of a shopping cart, followed in 2004; and Curiosity is the size of a car, with a design life of two years. Learn how these machines work as well as what they have found and hope to discover - and look forward to the possibility that humans may yet set foot on the Red Planet.</div>