Expert: Todd Panico - 10/17/2007

Question
QUESTION: I was thinking of adding fins just behind the nose cone apart from the rear fins. Will it increases the stability or simply increase the drag.

ANSWER: Hello Veerendra - The answer is both. Most likely it will add more drag than the benefit of stability. If the rear fins are well designed and properly applied, they offer all the stability that is needed.

Good luck,

Todd

---------- FOLLOW-UP ----------

QUESTION: the idea of adding extra fins behind the nose cone apart from the rear fins was to fire the rocket from a hollow barrel or tube, to keep the axis of the rocket along with the axis of the tube. So if the fins behind the nose can be eliminated, what are the other procedures to keep the rocket along the axis of the tube.

Answer
This is out of my expertise. But, from what I know about tube launched rockets (military types) either the nose of the rocket is the same diameter as the tube (as in mortars). Or the fins are retractable and deploy as it leaves the tube. Some rockets appear to be launched from tubes, but are actually on rails (I believe the Patriot missile is launched like this). The 'tube' is more of a dust/dirt/water cover than a launch stabler.

In short, the rocket has to be 'guided' until it reaches a speed that will allow it to 'guide' itself. So, in your application, you will need forward fins or an internal rail system.

Hope this helps,

Todd

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