Considering that the most problematic aspect of landing on a planet is a surplus of (kinetic) energy, why not find a way to take a long glide through the atmosphere while converting some of that energy and storing it in a form that can power a propeller, rocket engine or other device to slow down the last phase of descent? The air friction from this energy collecting phase would also serve to slow down the descent, making the final phase all the easier.
As far as forms of energy which could be converted to for
storage: there's the possibility of converting CO2 to carbon
carbon monoxide and oxygen; there's charging batteries to
power a helicopter propeller; and
Hmmm, I wonder if some of the principles of scramjet design could be used in reverse for braking? If you're making compressed O2, you'll need a way to bottle it in a hurry without creating excessive hazards for the crew. Anyhow, I'm glad someone's finally recasting the term "Martian flying saucers".
Force needed to accelerate 2.2lbs of cookies = 1 Fig-newton to 1 meter per second