3/4 Mercury Redstone

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Hope this helps.
If you guys have any further questions about parachutes or rigging, please just let me know.
I'd be happy to help in any way possible.
 
mikec,

Thanks for your reply. You are a steely eyed rocket man. Landing at 15 feet per-second is equivalent to simply dropping the piece from one meter. Impact should be about 7,000 pounds force assuming the 350 pound booster leaves a 2 inch dent in the soil. Estimating the dent, of course, is the thing.

We’re going to see if some friends in FEA can run a 1 meter drop test on the booster.

Feckless Counsel
 
Happy New Year Feckless!

You have a great project & I wish you success on this venture.
Definitely a long hard road with many choices to make.

Recovery is the beyatch.....hope for the best......prepare for the worst!
I've snapped 4800lb line like it was kite string, when things went south on a 300lb project.

Drogue stripped, and main opened to quite a shock load. Parts horizontal [payload, nc, fincan] rather than vertical stacked.
But other than minor repair to one fin & replacing 1 zippered tube...it flew again! Prepare for the worst!!!
 
TRF,

Today was our first design review including core team, MDRA board members and Tripoli TAP members. Total attendance was 12 people. Review included a summary PowerPoint presentation, flythrough of the 3D model and simulation results from the FEA team. Criticism was well received. We have several pages of follow-up notes. We also received commitment for construction space beginning March 2017.

Consensus is this project flies April 2018. That is the most reliable date for an MDRA / Higgs Farm flight. Given Higgs is the place of historic flights our first hope is to fly there.

Feckless Counsel
 
TRF,

Attached are some of the slides discussed at this week's design review. Included are:

1. Basic details of our proposed construction.
2. Sequence of flight to 5,200 feet.
3. Booster separation schematic.
4. Capsule and tower separation schematic.

Feckless Counsel

Capsule separation scheme.PNG

Redstone Flight Sequence Proposal A.PNG

Semi-monocoque Details.PNG

Booster separation scheme.PNG
 
How confident are you of the main body freefall q streamlining and having high speed or tumbling causing recovery issues.
 
I started to ask you to share the PowerPoint when you previously mentioned it. Please share more if you can. Very interesting.
 
How confident are you of the main body freefall q streamlining and having high speed or tumbling causing recovery issues.

I was thinking the same thing. Well not in the same words but I was going in the same direction of being concerned with a drogue-less, free-fall and the mass of the objects. Of course not knowing the mass is at the root of the concern.
 
Ditto. I think if you try to bring this stuff down drogueless you will strip the mains almost guaranteed. I've never seen a big project try to do dual deploy of any kind, most are challenged enough getting the chute out at apogee intact.
 
Everyone,

Thanks for your comments on recovery. A significant part of the design review considered recovery area, altitude and thrust-to-weight ratio. Dual deploy option was developed anticipating an ability to lift the project one mile altitude. Drogueless summersaulting, flat spin and nosediving trajectories were considered. The effect and hazards of including a drogue were also debated.

Single apogee deploy and flight to 3,000 feet is a simplifying specification. And we all understand how simplicity favors success.

Feckless Counsel
 
Fleckless, from you first post you provide a projected date as above. Will this be at LDRS36 in Maryland then?

Consensus is this project flies April 2018. That is the most reliable date for an MDRA / Higgs Farm flight. Given Higgs is the place of historic flights our first hope is to fly there.

Apr 2018
 
dixontj93060,

We really want to fly this project at LDRS 36. Our host club never refused the project but it is clear they prefer to separate it from LDRS. Given the field, crowd size and other logistics that is completely understandable. Respectfully we have backed off and will begin construction about 10 March, a date otherwise more convenient to our construction facility. We expect 6 weeks total construction time.

Availability in the fall is unreliable because Higgs and the surrounding properties are working farms. That puts the next available and reliable launch date early 2018.

You could say we have a full year’s schedule slip. We like the idea this project was too large and dangerous for LDRS.

Feckless Counsel
 
TRF,

Just for fun. Below is the scale study from our design review.

Feckless Counsel

Given the flight profile of the full scale Aussie V2 and its lightweight construction techniques, and seeing this comparison, I am now getting very worried.
 
Diameter is smaller and they are saying they are using a Q motor, where the V-2 used an O-25,000.

Given the flight profile of the full scale Aussie V2 and its lightweight construction techniques, and seeing this comparison, I am now getting very worried.
 
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Diameter is smaller and they are saying they are using a Q motor, where the V-2 used an O-25,000.

Well yes, but the mass? V2 was very lightweight build. Just the tower on this thing has to be fairly hefty.
 
?? I show this anticipated at ~10% less mass?

I dont' think he believes the mass calculation based on the size, I think the structure looks pretty light, but we'll see how it works out, I'm sure they can do a good estimate of that.
 
Given the flight profile of the full scale Aussie V2 and its lightweight construction techniques, and seeing this comparison, I am now getting very worried.

It appears they are doing a construction analysis so they could be in good shape. The Q powered Pershing missile failure some years ago was a "builtup" rocket I heard they say it structurally failed at a transition though
I didn't read a final analysis so that might be incorrect. The Aussie V2 at the outset was designed to be low and slow and the builders certainly were successful in that regard. People who were calling for "a larger" motor
didn't recognize the capabilities of the V2 design but the rocket did exactly what the builders designed it to on the motor chosen. Any motor larger and it could have structurally failed.

Kurt
 
It appears they are doing a construction analysis so they could be in good shape. The Q powered Pershing missile failure some years ago was a "builtup" rocket I heard they say it structurally failed at a transition though
I didn't read a final analysis so that might be incorrect. The Aussie V2 at the outset was designed to be low and slow and the builders certainly were successful in that regard. People who were calling for "a larger" motor
didn't recognize the capabilities of the V2 design but the rocket did exactly what the builders designed it to on the motor chosen. Any motor larger and it could have structurally failed.

Kurt

I may make a special trip to Higgs Farm just to watch this "baby."
 
TRF,

Please consider the following:

1. Five-to-one ratio of thrust-to-weight is preferred especially where big EX meets big airframe.
2. Lower risk EX motors are designed to neutral thrust curves operated at marginal pressures.
3. Maximum Higgs Farm altitude for single deploy flight is 3,500 feet.

If you generally concede these points then there is potential conflict between item 3 and the first two. That is to say you may be over 3500 feet given 5:1 for 6 seconds in 8 inch diameter by ¼-inch wall 6061 aluminum design.

For sake of argument let’s say we are presently at 800 pounds all in except the motor.

Feckless Counsel
 
Perhaps reefing the chutes, released at break, and letting them fall under a pilot until the altitudes you mentioned? This would be dual-deploy... ish... and should minimize the chance of components rotating into a ballistic freefall position...


Later!

--Coop
 
Coop,

Thanks for your reply. We’ve discussed this a lot since December. Plan now is to keep it 3,300 feet (1 kilometer) altitude and spill the laundry on top. Decision is driven by the potential forces at mains deployment after free fall.

To achieve that flight we are considering a dual thrust motor. There are several reasons to favor that profile. We want 5:1 thrust to weight at lift off. We want to throttle down for altitude target. We may also operate higher pressure early in the burn where case temperatures are lower.

I visited the construction facility this afternoon. It’s looking really good. Open area is about 50 x 90 feet. Electricians are almost done. Place is freshly painted. Many machine tools have arrived awaiting installation. We should have access about 15 May.

Feckless Counsel
 
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