In 2012, NASA’s Mars Exploration Program landed a sophisticated new roving vehicle on the Red Planet. Dubbed the “Mars Science Laboratory” and also known as “Curiosity”, it is much larger than the Mars Exploration Rovers Spirit and Opportunity, and is planned to operate on the surface for at least an entire Martian Year or 687 “sols”, representing a dramatic increase over the planned lifespan of 90 “sols” that the current rovers are designed for.
To power the Mars Science Laboratory, mission planners utilize a nuclear engine, in the form of Radioisotope Thermoelectric Generator (RTG). It is a much more powerful version of the same technology that powered the twin Viking landers, which survived for years on the surface of Mars. The generators will provide a greater level of power for science instruments, and also get around the limitations of solar panels; eventually dust from the martian atmosphere will tend to coat solar panels, lowering their ability to generate power. This fact will ultimately doom the solar-powered Mars Exploration Rovers, if nothing else does.
JPL created a new landing method for the Mars Science Laboratory that will utilize a “Skycrane” to drop the rover package onto the surface, marking the first “wheels down” landing on Mars. It has allowed the new rover to begin its investigations immediately, with no need for airbags or the long period of unfolding, standing up, and checking itself out that the Mars Exploration Rovers had to experience.
The Skycrane concept made use of a powered descent, slowing the spacecraft down and allowing it to hover a mere 15 feet (5 meters) above the surface. Then, the rover package slipped down a tether, and the rover itself deposited softly onto the ground, ready for surface exploration. The Skycrane apparatus then cleared the rover with a short hop away, crashing itself safely away from the landed rover.