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Originally Posted by ghrocketman
Seems to me it would be easier just to use bullet-proof chutes, shock cords and attachment methods than focusing too much on DV.
In this area a little can go a long way as delays for certain manufacturers motors are notoriously inaccurate.
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It's not so much bullet-proof, GH, as it is shock absorbing. I agree they need to be sturdy, but the key is damping. I prefer tape loops on the shock cord. That way, during a hard deployment, the tape gets torn thus dissipating the shock. (Elastic will dampen, but it stores the energy, then releases it in the form of pulling the nosecone crashing into the rocket
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The damping allows the use of lighter shock cords and parachutes, which reduces the overall system stresses. The other key is making sure the shock cord is wide thru the opening of the rocket to minimize zippers.
I've had so-called experts tell me the best solution is selecting the right delays, but I know better. Too much crap can happen, especially in the Texas wind, to get it out at the top with minimal DV every time. So a robust recovery system is needed, and is not overkill.
This rocket is a great example. With a four-motor booster staged to a single motor sustainer, with the higher likelihood of one booster motor out, flying in the nearly perpetual cross wind here, high DV is almost unavoidable. It has to be built to tolerate the hard jerk that often occurs at deployment. Doug .
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