Experimental LOC Launch – 1

DMC-FX7

ƒ/2.8

5.8 mm

1/60

100

You meet the most interesting people at BALLS. Jim Green pours his own motor propellant. He machines custom motor casings, nozzle, and closures. Each of these is a potential point of failure. =)

Here he is cutting the red “sparky” grains to increase their surface area (accelerating their burn). The red propellant contains a titanium sponge and Midas brake filings among other interesting ingredients. We used one of his green “Swamp Gas” grains instead of a delay charge.

On the flight out to Black Rock, I was reading the Apogee Components (RockSim) book on rocketry. Page 131 reads:

Making Rocket Motors
“NO!!! NEVER!!! Do not attempt to make your own rocket motors! Many people have died during attempts to make their own rocket motors.”

So, I got Jim to sign the page in my book. =)

(Next)

4 responses to “Experimental LOC Launch – 1”

benjiman

Oct 4, 2006 at 12:27 am

As I learned when I was a machinist….

"Measure twice. Cut once."

Reply
j_silla

Oct 4, 2006 at 8:45 am

If I just knew how to make rocket motors, I would do it instantly 🙂 what is he making them out of?

Reply
mmealling

Oct 4, 2006 at 1:58 pm

If you did it instantly you’d probably end up killing yourself or being burned very badly. Mixing your own propellants is an engineering exercise that requires precise measurements, lots of testing, and an understanding of the underlying chemistry and the resulting combustions properties.

Those particular grains use ammonium perchlorate as an oxidizer and the metals as fuel. The rest is a synthetic plastic binder that keeps all of that mixed together correctly. The Space Shuttle’s SRBs use something similar. It requires hours of mixing very slowly (to much friction and some will auto-ignite), packing, curing, cutting slowly, etc just to get a batch that you can do characterization tests on. And it ain’t cheap.

If you seriously want to get involved in doing that you should join your local Tripoli group and learn how to fly on commercial motors. Get at least your Level II certification and then find one of the reputable groups that can introduce you to the science safely.

We’ve lost several people in the hobby over the years to this stuff. Its even killed experts who had been working with it for decades. Its not something to play with…

Reply
jurvetson

Aug 10, 2011 at 1:07 am

I agree completely with that. I have done some mixing with professionals, but even now, would not embark on such activities on my own.

Reply

Experimental LOC Launch – 1

4 responses to “Experimental LOC Launch – 1”

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