Curiosity and Descent Stage, Artist's Concept
This is an artist's concept of the rover and descent stage for NASA's Mars Science Laboratory spacecraft during the final minute before the rover, Curiosity, touches down on the surface of Mars.
The use of powered descent creates a robust and efficient touchdown system.
Unlike any of NASA's earlier rover missions, Mars Science Laboratory was powered down to the surface of Mars, instead of being delivered by way of airbags. After the parachute significantly slowed the vehicle and the heatshield (that protected it from intense friction during atmospheric entry) was discarded, the descent stage began to ease the spacecraft to the surface. Reverse rockets stabilized the vehicle, protecting it from any horizontal winds. As Spirit and Opportunity were lowered via tether, Mars Science Laboratory too was lowered, but with a trio of tethers and an electrical "umbilical cord."
Completely unlike its predecessors, Mars Science Laboratory was designed to be "ready to rove" upon landing. While the Mars Exploration Rovers had to wait for their lander petals to "blossom," Mars Science Laboratory shed its cocoon on the way to the surface. Mars Science Laboratory's mobility system - the wheels and suspension - were released while the rover was headed to the martian surface.