Proposed modification to Saturn V recovery system

[Jupitertwo]

I seek advice on the viability of a modification to the recovery of an Estes 1/100th scale Saturn V. Rather than having the Saturn V upper stage and booster return separately, I want them connected by a common shock cord. They both retain their own parachutes. The upper stage would act like a nose cone in this arrangement deploying both its own parachute and that of the booster. This is best visualized in the attached graphic. In addition to "will this work," I ask for advice on the recommended lengths of the individual cord segments annotated as A, B, C, and D in the graphic.

 

[TRWXXA]

I seek advice on the viability of a modification to the recovery of an Estes 1/100th scale Saturn V. Rather than having the Saturn V upper stage and booster return separately, I want them connected by a common shock cord. They both retain their own parachutes. The upper stage would act like a nose cone in this arrangement deploying both its own parachute and that of the booster. This is best visualized in the attached graphic. In addition to "will this work," I ask for advice on the recommended lengths of the individual cord segments annotated as A, B, C, and D in the graphic.View attachment 595669

My concern is that the two parts are going to fall at different rates. If the upper stage falls faster, then the two halves might bang together as they pass, and then both parts will essentially be hanging from one chute. If the upper stage falls slower, then it will rise above the lower stage, and possibly entangel the lower stage's parachute. Then both halves would be descending on just the smaller chute.

 

[techrat]

^^^^ I agree with Chris -- you are better off eliminating shock cord piece "A", and have the two halves come down as separate pieces. It seems like you're trying a hybrid of dual-deploy and separate chutes. There's probably a reason nobody does what you are attempting and that's likely because of chute/shock cord entanglement.

 

[mikec]

Having flown various Saturns that recover the standard two-piece way, it's hard enough getting it to work correctly without the added chance of the two pieces tangling or rebounding into each other. Why do you want to connect the two?

 

[t.g]

My concern is that the two parts are going to fall at different rates. If the upper stage falls faster, then the two halves might bang together as they pass, and then both parts will essentially be hanging from one chute. If the upper stage falls slower, then it will rise above the lower stage, and possibly entangel the lower stage's parachute. Then both halves would be descending on just the smaller chute.

Agreed. That’s why a long shock cord between the two is important to maintain separation. This idea sprang from seeing the descent of rockets using both a drogue and a main parachute connected by a common shock chord.

 

[mikec]

The only possible advantage I can think of is that the pieces can't end up in different locations. In my experience at the low altitudes these are typically flown to, the two pieces land close to each other anyway. Trying to tie them together may lead to them landing at the same location, but perhaps all tangled together and broken by impact when the chutes don't open. YMMV, just my two cents having flown these many times in the stock configuration.