Mars has enough of an atmosphere that it will burn up your spacecraft if you’re not careful. But the atmosphere is too thin to slow down a large craft for a soft landing. Curiosity is too big and heavy to pull the bouncy ball trick that they used with Spirit and Opportunity.
So what’s NASA’s plan?
1. A heat shield to begin the slowing.
2. A parachute will deploy.
3. The heat shield will be jettisoned, so the lander can see the surface.
4. A rocket sky crane with the rover will be released from the parachute.
5. After dodging the parachute, the rocket will navigate to the proper location.
6. Then the sky crane lowers the rover to the surface, before rocketing off and out of the way.
What could possibly go wrong?