Airbags are inflated bags, which cushion the lander as it lands on the Martian surface. They must be strong enough to cushion the landing even if the craft lands on rocks or rough terrain. The airbags must be inflated seconds before touchdown and deflated once safely on the ground.
The fabric used is a synthetic material called Vectran. Vectran has almost twice the strength of other synthetic materials, such as Kevlar, and performs better at cold temperatures.
Each rover uses four airbags with six lobes each, which are all connected. Connection makes the bag flexible and responsive to ground pressure. There are three gas generators, which are used for inflation.