My all-fiberglass Nike Smoke rocket became a spiral flamethrower overhead

6 responses to “My all-fiberglass Nike Smoke rocket became a spiral flamethrower overhead”

1. 

   jurvetson

   Oct 21, 2014 at 6:43 am

   At the pad burnt fiberglass Melted aluminum motor casing

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2. 

   gsikich1

   Oct 21, 2014 at 8:59 am

   Nice series; especially this last one

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3. 

   Wind Watcher

   Oct 21, 2014 at 2:53 pm

   Flamethrower indeed! Like the series showing the progression. Any ideas on the root cause of forward closure and the side wall blow out? External (camera ?) mount have any impact?

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4. 

   jurvetson

   Oct 21, 2014 at 9:36 pm

   Good question! The camera was external to the body, and unrelated to a failure that started inside the aluminum motor casing.

   Since the motor stack was prebuilt, there is not a particular "operator error" to point to. It’s important to inspect the liner for cracks and the o-rings for a good seal, but ultimately, the fissure point here has been thoroughly destroyed by the burn. The pressure is highest at the top of the motor, and there are a number of interfaces between case and cap and delay grain.

   We had a lot of pre-built motor CATOs this past weekend. It’s a bit frustrating as there is no particular learning for next time on this one… just some bad luck of the manufacturing draw…

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5. 

   rocketmavericks

   Oct 23, 2014 at 3:33 pm

   Looks like another cracked grain and motor overpressured. This is usually how Cesaroni motors are designed to fail for safety. The motor case fails at the forward closure. Too bad. I always liked this rocket.

   Post the rocket Leif and I put together. I wanted to see the DM motor. Man it went high. At least we had one good flight for the team!!

   Oh, also, it was the I-140 motors were the ones we had the failures with. Looks like a bad batch of motors with smoke grain burning through. We only had 5 out of 56 flights, and considering we still recycled 3 of the airframes after repair to certify again, a pretty good day. I think we may have broken the Tripoli record of the largest number of successful certification flights in one day. Guess Mavericks In The Classroom training program for educators is working!!! Woot!!!

   Here are some images from Stanford’s program:

   http://www.flickr.com/photos/rocketmavericks/14644627077/in/set-...
   http://www.flickr.com/photos/rocketmavericks/14644455330/in/set-...

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6. 

   jurvetson

   Oct 24, 2014 at 4:36 am

   Sure. Here you go…

   Reply