I want to clear up what I believe is my own misunderstanding.
I'm very familiar with the concept of spin-stabilization, and my understanding of it revolves around giving the vehicle a very high spin rate in order to resist aberrations in thrust, aerodynamics, etc and average out forces during the flight.
However, discussions with a friend have brought the concept of the "spin-can" to my attention, which allows only the fin can to spin, keeping the body tube stationary. It has, apparently, been flown successfully, and is described in-depth in this video:
Now here's where my understanding breaks down. He's told me that doing something like this is more or less just as good as a full spin-stabilized setup, as the rest of the rocket is aerodynamically symmetrical, and any minor mass imbalances don't spiral into full-on precession.
I'm inclined to believe him, but I'm somewhat baffled as to why. Surely the moment of inertia on the spin-can is significantly lower than that of the entire rocket, and that can't be good for stability. Additionally, as far as I'm aware, the spin-can was invented to handle a control issue rather than a passive stability one, so I'm not sure if it's beneficial for most applications.
Where is my logic going awry?
I'm very familiar with the concept of spin-stabilization, and my understanding of it revolves around giving the vehicle a very high spin rate in order to resist aberrations in thrust, aerodynamics, etc and average out forces during the flight.
However, discussions with a friend have brought the concept of the "spin-can" to my attention, which allows only the fin can to spin, keeping the body tube stationary. It has, apparently, been flown successfully, and is described in-depth in this video:
Now here's where my understanding breaks down. He's told me that doing something like this is more or less just as good as a full spin-stabilized setup, as the rest of the rocket is aerodynamically symmetrical, and any minor mass imbalances don't spiral into full-on precession.
I'm inclined to believe him, but I'm somewhat baffled as to why. Surely the moment of inertia on the spin-can is significantly lower than that of the entire rocket, and that can't be good for stability. Additionally, as far as I'm aware, the spin-can was invented to handle a control issue rather than a passive stability one, so I'm not sure if it's beneficial for most applications.
Where is my logic going awry?