Design Requirements for Level 3 Rockets?

• Maximum velocity, acceleration, altitude
• Maximum angle of attack depending on wind velocity
• Drift, depending on wind
• Velocity off the rod
• Velocity at deployment
• Stability, depending on AoA, time & velocity

ksaves2 said:

Cd as a function of velocity? Why? I've not known that to be a requirement. I admire folks who want to "push the envelop" on a cert flight but it simply is
not necessary. A 3FNC with motor ejection is just fine for an L2 and DD is really not a requirement. I did that and futzed around with H and I DD rockets and continued to fly J's with motor ejection. Finally did an L with DD and did fine. I say keep it simple and then go from there. If you want to make it hard and complex, go ahead but the opportunity to fail goes up. The point is the acquisition of skills can be gradual and one doesn't have to do DD for the L2.
Can acquire it over time. Actually if one wants to, they can do apogee only for an L3 flight. Only issue there is the rocket will have to be large and that can be
a problem for some fliers. Saw a successful A-only L3 flight with a baby M that went to 1300'. No rule says the L3 has to be DD.

The only thing I know is look on the Tripoli or NAR cert form. That's what's required. (Plus the provenence of every part used in the rocket in the documentation) I think it's inappropriate for a TAP person to demand a "porcelain level" of the body tubes and whether or not the expected altitude will be different in Ho Chi Minh City, Vietnam as opposed to Laredo, Texas. Rocksim, Open Rocket or what have you simulator to suggest stability and that the rocket will meet the particular parameters and waiver of a flight venue is needed. If it's too windy to fly at a particular site, don't fly. If one can do a test flight of an L3 rocket with an L motor, video it for documentative purposes. Catch the whole flight including the descent. That should help but again, it is not a requirement for presentation. (Could help one get by the Cd as a function of velocity vagary)
If the TAP or L3CC is going to try to pimp you because you don't have the "exact" descent parameters of the chute you use, complain to the hierarchy.
Nobody should suffer because a particular TAP or L3CC pulls out some obscure garbage to hold a candidate to.
As an aside, I've seen complex L3 candidate flights there were perfect and then over time, the person's followup projects fly marginally or with adverse events.
I have two L3 candidate rockets I took pictures and video of some of the constructions steps. Can't decide which one to submit yet. If the pictures, video and my personal explanation during inspection with the TAPS (along with the parts list and rocksim simulations) isn't enough, screw 'em. I'll stick with less than M motors and the only people who'll suffer are the commercial motor makers. Kurt

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Area66 said:

Are you with the Ecole Polytechnique de Montreal or the ETS




Kurt he is not going for Lev 3, they participate every year @ that competition, they bring with them a Lev 3, those are engineering students.

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stealth6 said:

I was out at the launch site for the IREC/ESRA event this year. It just so happens to be "in my neck of the woods" (I live in Moab). Very cool event, and a treat for me as it's the ONLY rocketry event that happens anywhere near where I live. I'm definitely hoping to be able to attend again next June. I'll look out for you and your project - keep us posted here as your project develops and takes shape - pics/videos/plans/projections!

s6

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Neilw said:

I definitely will. In fact, I may try to post the thread tonight. I'm from Concordia University in Montreal (same city as ETS and Poly. We sometimes cooperate) and our society is called Space Concordia Rocketry Division (we're part of a larger society that does satellites and robots and stuff).

For Ksaves2:

Can you explain some of those acronymns, please? (TAP, DD, L3CC)

Also, we are trying to get very specific telemetry on our flight. We're using a new type of programming for the flight computer. as part of the competition, we want to be able to validate our simulation software within a high degree of precision so that in following years we'll be able to really know exactly what the rocket will do. This is why we're trying to test as many parameters as possible.

(edit: I realize this post may have come a bit late for you Ksaves2 XD)

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ksaves2 said:

These are for folks that want to certify Level 3 in US. They have to approach these contact people with their projects for approval before they can attempt a certification flight at the L3 level.

TAP = Technical Assistance Panel for the Tripoli Rocketry Association
L3CC = L3 Certification Committee for the NAR

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ksaves2 said:

These are for folks that want to certify Level 3 in US. They have to approach these contact people with their projects for approval before they can attempt a certification flight at the L3 level.

TAP = Technical Assistance Panel for the Tripoli Rocketry Association
L3CC = L3 Certification Committee for the NAR

DD = Dual Deploy rocket. (Apogee event and then Main event)

I misconstrued your question as one concerning a certification with a rocketry group and not for an academic endeavor at a university level. I apologize for
my misunderstanding. In an academic environment they can throw at you whatever they want to get you trained!:grin: Kurt

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jimzcatz said:

Kurt, FWIW, I agree with everything you said about TAP involvement. It should only be as an advisory level and never "you gotta do it this way or not at all", not unlike some stories I have heard of! To the OP, good luck on your project.

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