Since the days of the Viking landers, which were the last space probes to visit Mars and successfully beam back information from its surface, countless designs for the next machines to explore the red planet's terrain have been presented to NASA.
Among the robots being tested for the job is a huge, super-intelligent, six-legged machine at Carnegie Mellon University in Pittsburgh, Pennsylvania. It is called Ambler, and one of its main tasks would be to collect Martian rock samples to bring back to Earth.
Ambler's creators are taking much of their design concept from human beings. Like a person, Ambler learns things -- such as how to walk over rough terrain by rotating its two sets of metal feet -- that will help it do its job. The engineers behind Ambler are developing a vision system for it based on sophisticated stereoscopic cameras that can register depth. They are also giving it radar sensors that can determine the difference between solid ground and a sand pit and a silicon brain that will be loaded with a complex map of whatever area Ambler is exploring. The map would let Ambler make decisions; it would have to be supplied by orbiting satellites that would be sent ahead of the robot.
Once on Mars, Ambler would be on its own. Operators on Earth would not be able to guide the robot using remote control because radio signals take at least twenty minutes to travel between the two planets. A delay like that in reaction time could be disastrous.
Because of these complexities and the costs involved in preparing such a sophisticated robot for a full-fledged mission, Ambler probably won't be the first robotic explorer on Mars.
NASA has also contracted the Jet Propulsion Laboratory in California to build a more conventional rover that would be able to do the same job.
