Go to the Jet Propulsion Laboratory website and check out the newest video showing the Mars Science Laboratory mission, and you’ll see the latest and greatest design for a roving mission to Mars. I’ve clipped and posted a few screen caps below.
The first part of the video shows the landing, which will not be at all like the last three successful Mars landings. Pathfinder, Spirit, and Opportunity all landed by means of an absolutely crazy scheme where the whole hundreds-of-millions-of-dollars’ worth of spacecraft was encased in airbags and smashed at a relatively high speed onto the surface of Mars, bouncing a dozen or more times until rolling to a stop. That system produced three successful landings in three attempts, so the engineers clearly knew what they were doing, but I have got to say that, to me, that seems like no way to treat a spacecraft.
Mars Science Laboratory (abbreviated MSL) is much bigger than Pathfinder, Spirit, and Opportunity and absolutely cannot use the same landing technique, so the engineers had to go back to the drawing board. They’re using a heat shield and parachute to decelerate through Mars’ upper and middle atmosphere, the same as Pathfinder and the rovers, but after that the landing system changes. In the video, you’ll see the heat shield fall off and — surprise! — there’s no lander; while MSL is still way up in the air, the six wheels are already out and ready to touch Martian soil. Retrorockets fire, slowing the descent, much like Viking. The descent slows and slows. Then the rover is lowered on cables to the ground as the backshell — retrorockets still firing — floats overhead.