The product of over four years of design, redesign, and testing, the Mars Helicopter is a small, autonomous rotorcraft about the size of softball and weighing in at less than 4 lb (1.8 kg). It has the potential to revolutionize the study of other planets by introducing robotic heavier-than-air aerial vehicles to the task of deep space exploration.
The exploration of Mars has come a long way since the first Viking landerssuccessfully touched down in 1976, but there is still a long way to go. Nuclear-powered and solar-powered rovers may have greatly expanded the territory at the disposal of space scientists, but they're still very limited. NASA's Opportunity rover is a long-distance champion by Martian standards, clocking up 25 mi (40 km), but that took it 14 years. The average cyclist on Earth could cover that easily in a couple of hours.