Dual Deployment with drogue in Upper Body

[Sailfish1957]

I have 4” Hyperloc 835 under construction. The upper body tube has a small area for a Main, given the e-bay (upper half) and nose cone base using up a lot of space.

I am thinking of putting the drogue/streamer up there and the main in the lower body of the airframe. A reverse setup from usual DD.

It’s a big rocket, but I’m going high altitude, so there will be “time” to pull out the laundry.

Thoughts on this would be greatly appreciated.THNX

 

[SDramstad]

I like breaking mine near the middle for drogue deployment. It has a better chance of falling flat. By ejecting the drogue from the top some rockets are still fairly aerodynamic and may come down ballistic then end up zippering your body tube when the main comes out.

 

[Kane]

The issue to consider is the respective weights of each of the separated parts of the rocket during descent. When the drogue deploys in an ideal DD setup, it will descend such that the section of airframe containing the main is extended roughly horizontally from the drogue with the drogue section of airframe positioned below. This arrangement mitigates the risk of the main deploying and becoming tangled in the drogue. The reason the drogue typically is located in the lower section of airframe is because that is typically the heaviest section of airframe and is more likely to hang below the deployed drogue, whereas the upper section being lighter will extend horizontally from the drogue. Your proposed arrangement would certainly work if the respective weights of the upper and lower airframe work out as described.