Dropping an object from really high, landing at 0 velocity due to 'free' reverse thrust So a friend had an 'idea' where you could make an object land with 0 velocity. 

Basically the idea is that you drop an object (like a rocket shape) from some altitude. To the object you attach fins (fixed propeller blades so to speak.) as it falls it starts rotating, due to the attached fins.

Now at some altitude above the ground you either:

1) You rotate the fins to get reverse 'thrust' (you don't really have thrust, but you would slow down rotation.) 
2) Retract the fins and expand new ones that face the opposite way (so they counter spin)
3) something along those lines (like extending flaps)

Now one of the arguments he had as to why this works is because you could expand larger fins for the counter rotation, therefore getting more drag and generating more 'lift'. 

It feels like you cannot do this, but I cannot give a (good enough) reasonable explanation as to why it would or would not work (I'm a noob in this area.) So let's ask the people in the know... that's you.

I would love to see some 'proof' more so than speculation.

Thank you in advance.
What you are describing is similar to a helicopter autorotation.  That is something that does work.  The rotors both generate drag and store rotational momentum.  Then, some of the momentum is converted to lift for landing.