Go to any high school science fair and you'll probably see an example of a compound pendulum tuned to behave as a chaotic system. MSL's bungee cord is a compound pendulum. It can't be physically tested on Earth because the initial conditions require descending at 200 mph then experiencing gound effect and plume impingement on a swinging payload with sloshing fuel tanks driving a throttling rocket in a 6 millibar atmosphere at 38% gravity. This can't be adequately simulated in a computer, i.e. turbulent shear layers mixed with a potentially chaotic dynamic system, (no way, Jose). There is no doubt or mystery here. If they go with the bungee cord, MSL will auger in and a billion dollars will be pissed away.

Gary