Places to launch/ do qualification runs for ARC
Hi,
I am the head of an ARC team that’s run under Up And Above Space, a non-profit that is meant to bring aerospace experiences to students in NYC. We have been struggling to find a location to launch (we need to launch a few times before march 30th) and, since this is my first year doing this, I do not know how to do the qualifications for ARC. If anyone has any advice on places to launch or knows how to do qualifications, please reach out. Any help is greatly appreciated.
Thank you,
Sky Epstein
I’m out at the moment. Our field and expertise is available. I will provide more information tomorrow.
Charlie Kirlew
Great! Thank you so much!
I/we have been suggesting that ARC teams get out and launch as early in the school year as is possible. We all reside in the NE US and that means we could have great weather throughout the winter or we could experience what we have seen this season.
I have requested use of the sport complex where we fly for the next four week. I have yet to get approval but should CENJARS get that approval, please make the most of it!
I assume you have read and understand most of the documentation for the ARC challenge. Most teams that qualify for the National finals do at least 12-15 test flights before they do their qualification flights. You must do 2 qualification flights and are allowed a maximum of 3. These flights must be declared before the flight. We will help you through this. Also, we have a number of ARC teams attending our launches so you will get to see what others are doing and how we try to keep the process moving along.
You should have at least 2 rockets, altimeters, and eggs with you. You don't want to truck out to the wilds of New Jersey and only get one failed flight. Every flight is a learning opportunity.
There isn't any public transportation that comes near our field so car or school bus is the best transportation.
That's some of the basics. If you have done any design work in OpenRocket or RockSim, I can review your files to see if there are any significant concerns. Please let me know what specific questions you have.
Charlie Kirlew
Yes, I have read all of the rules and documents. I have done ARC in the past, but this is my first year being in charge.
Attached is the .pdf containing all of the design details and simulations. We are planning to use the F32t-6 motors. We are using airbrakes this year due to the variable height target during finals, and thus the rocket is designed to go over the target for qualifications (750 ft but the rocket goes to 850 ft). Adjusting for the correct altitude that would be obtained when using airbrakes, the timing is nearly perfect based on open rocket sims (though I know these can be inaccurate). One thing I am worried about is the ground hit velocity. The nose cone, air brakes, and motor retainers will be 3D printed, the fins and centering rings laser cut, and the body will be made out of craft paper (bought from apogee). The airbrakes will open based on velocity and altitude given by an accelerometer and an altimeter (separate from the one used for determining the height of the rocket, per ARC rules).
Thank you for all of your help, and I hope to see you soon for a launch,
Sky Epstein
Uploaded files:Do this year's ARC design rules require elliptical fins? I fail to understand the small fins chosen for ARC rockets with respect to their larger airframes and or payloads.
No requirements related to fins except that the rocket has to land safely and intact. They have 4 fins so that will help. Max gross weight is 650 grams. They are getting a little close with what is listed in the PDF. As long as all of their weights and locations are correct, they should be fine.
Two fin shapes of equal area — elliptical and trapezoidal. The trapezoidal will move the CP farther aft, and maintains a lower profile and more root edge for structural integrity.
Anyway, I was just curious about the fin design choice.
Elliptical is a little more efficient. Think of the RAF Spitfire.