This document discusses space robots and their importance. It notes that robots play a vital role in space exploration as the environment is very challenging for humans. Space travel can be dangerous and cause death, so robots help mankind explore planets more cheaply and quickly while saving human lives. The document then lists some important robots that have explored Mars, including Sojourner, which was the first Mars rover, and Spirit and Opportunity, which were designed to explore Mars as part of NASA's Mars Science Laboratory mission. Curiosity is also discussed, as it is a car-sized rover with the same mission objective.