My version of the Gary Larsen cartoon, "Not a Rocket Scientist".
At apogee (about 1,200 feet) this 45 pound rocket will separate into three parts under individual parachutes: nosecone, the long & crooked middle part, and the fin/motor section.
the fin/motor section is 36" long and weighs 18 pounds after the L1520 propellant is expended. The first 12" length of the body is 8" in dia, and the last 24" length goes from 8" to 12" in dia. at the base.
I plan to have ejection charges to separate the fin section from the upper sections, but do you think that drag separation will separate it prior to apogee ejection charge deployment? Even though the fin/motor section's chute will be protected in a Nomex deployment bag which will be attached to the bottom of the long & crooked middle part, I can envision the ejection charge for the fin/motor section going off just as the chute exits from the D-bag.
Just wondered if, based on the 8" to 12" dia. skirt on the fin section, you think/know that there will be drag separation before the rocket reaches apogee. My guess- and it's not based on any calculations- is yes.
There are a couple of options I have, such as attaching the D-bag to maybe a 10 feet long piece of Kevlar cord so that when the chute does exit the bag, it will be far enough away from the ejection charge to have serious damage done to it. I could also have a 96" Nomex chute made and not worry about the blast from the ejection charge.
Your thoughts? Thanks!!
