Moving Around on the Martian Surface
Our first rover to visit Mars, Sojourner, traveled about 100 meters (109 yards) over an entire month. The next two rovers to visit Mars, the Mars Exploration Rovers, will land on different parts of the planet. Both twins are also expected to have the ability to rove approximately 1 kilometer (about six-tenths of a mile) over the duration of their mission. Future rovers may travel over several miles on the surface, allowing us to move from a safe landing site to investigate surface features that are currently too difficult to access.
One approach to long-range mobility is inflatable rovers, which would use very large, inflatable wheels to climb over rocks, instead of traveling around them. This would allow inflatable rovers to travel much farther and faster than current rovers. These rovers are only inflated after arrival on the Mars surface. Prior to inflation, they are lighter and, when deflated, can be packed in a much smaller volume than a conventional rover of the same physical size. When deployed, the inflatable rover is approximately 50 times its packed volume, whereas a conventional rover is only two or three times bigger than when packed.
Rovers will also increasingly rely on smart technologies to know where they are, where they want to go, and which soil and rock samples are worth studying and collecting.
Future rovers may also have adjustable shoulders that allow them to drop low to the ground or elevate themselves to navigate through a gully or crater. They will no doubt conduct more sophisticated experiments, such as using ground-penetrating radar studies, to search for evidence of water.
Future rovers will also travel locations where they can rendezvous with other surface vehicles. Eventually, teams of robotic rovers might even work together to build an infrastructure of robotic colonies, laying the groundwork for human visits and human bases. Thus, if human exploration is indeed possible on the Red Planet one day, it will be robotic rovers that pave the way.