Rocket Challenge on Discover

Sanitary coverage = censorship

The slice of rocketry was very representative of a LOT of the hobby. Smoking around rocket motors showed some feel they are not very easy to light. Good or bad it showed something. Ejection failure on the pad showed it hurts your back when you hit the ground after faling 10 feetl. Showing the CATOs proved it was 'experimental' rocketry. No harm there. A failed chute and ballistic return waaaaay over on the ridge. Even some not so wise moves by the RSO on the snitch, I don't recall anything on the bottom of that thing resembling a motor mount. A flying outhouse with the owner more than honest to the guy loading on thenext pad over. His honesty was, I haven't a clue where it's going, load at your own risk.

It was good stuff. Had it been censored it would have been your government in action. IMO, the failures will do more selling than many of the successes. CATOs grab your attention, watching a guy belch out telemetry is informative, but not so spectacular. The only thing which made me cringe was, did they really say cowtastrophie?? :-)

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They moost certainly did.

This is the kind of exaggerated response that gets us stuck with excessive, idiotic rules. BP isn't like gasoline, it doesn't give off highly flammable vapors that can be ignited from a distance. And you'd need a heck of a lot of wind, in just the right direction and conditions, with an unusually "sparky" cigarette, to have even a remote chance of a spark from a cigarette traveling fifty feet and landing in the narrow opening of a BP can.

LOL! Yes, and it cracked me up! :)

Wonder what the odd were of a discarded cigarette that would take a bounce, travel through the fresh air intake, and land in my wife's lap, as she was driving down the road?

Joel. phx

Probably about the same as a driver flicking one out the window and it going down my shirt while riding my motorcycle. Man that hurts.

Bob

Better high your tail on down to the store and get you an asbestos suit. Ridin' them motorcycles is hazardous to your health, you know. Plus, you will be all safe if your house catches on fire.

Still have a crusty ol' "loogey" on the sleeve of one of my jackets. Nice. Real nice.

I shot a video of a rocket flying backwards and land on the rail under boost..........I then reversed it to make it *appear* to be taking off.......never believe everything you see on video........unless you're there in person you can't *really* be assured it happened

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You and I will have to agree to disagree then, Ray.

I personally have had ciggy ashes hit my skin after being blown more than

20 feet, thanks to someone's chance collision and a light breeze. If you approach me while I'm handling an open can of BP, ciggy in hand, I'm going to get verbally medieval on your ass. And by fifty feet, I'm setting up a safety zone which is not merely to protect against stray ashes, it's to allow a safety buffer in case someone gets careless, forgets about their ciggy (or just doesn't know what's going on) and decides to start walking towards me, before either of us can notice and react.

Agreed. Especially the igniters and ejection charges...

-dave w

I suspect the issue with respect to BP is primarily that in a very low ambient pressure, the hot gases from the first grains ignited will expand and cool too much to spread the ignition over the surfaces of the remaining grains. Also, since each grain burns as a solid propellant with a certain pressure exponent, the overall burn rate will be reduced (for the grains that are ignited).

-dave w

I'm with BB, Ray.

It's not just the probability of getting hit by an ash from

50 feet. (BTW, when I was smoking, I'd never toss a cig down at a launch. It was always vigorously snuffed.)

While that 50ft probability may be very, very low, in the world of risk assessment, you take that probability and multiply it by the consequences. The consequences of starting a grass fire are (typically) not too severe, but the consequences of igniting a 1 pound can of 4F are nuclear.

That teeny-tiny probability multiplied by that enormous consequence is a critical risk.

I'd rather be known for my "excessive, idiotic rules" than as a one-eyed, one-armed guy called "Lefty".

Doug

VERY low pressure exponent, which is what rocks about BP.

Yes, it's the outdoor magazine that is the issue. We've usually declared the entire parking/prep area, plus of course the range head to be no smoking. And someone always ignores that because they're used to smoking everywhere they go.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

agreed.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

As usual, after I shoot off my mouth (or keyboard in this case) I find something else. NFPA 1127 prohibits smoking within 25' of storage areas.

4.19.1 "High power rocket motors, motor reloading kits, and pyrotechnic modules shall be stored at lesat 7.6m (25 ft.) from smoking, open flames, and other sources of heat."

But I am not certain that motors at the flying field would consitute being "stored". The explosives industry certainly doesn't think so. (The ISEE response to NPRM 968 is interesting reading.

)

Which raises the question. Why would NFPA address something ATF already does and why make it different?

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Well, I was only reacting to what I saw - and I pretty much ignored the narration, as it was quite a bit of gibberish. I have been to any number of various modeling events - in fact, probably a factor 10 more than you have. And I have also gone to local HPR launches (which, I might add, demonstrated pretty much the same problems I saw at LDRS. And, by the way, have resulted in very large insurance payouts for punctured roofs - about 4 times in the last dozen or so launches. If it will puncture a roof, it will kill someone - and the small cross-section of a human body is not a valid counter-argument).

I certainly didn't take anything at face value - aside from the things that were obviously a bad idea. The short story is that it was being run pretty much like a modroc launch on steroids. But there are some assumptions in modrocs, like frangibility and light weight, that make it reasonable to run the launch with minimal range controls. These assumptions do not apply to HPR.

It's not just a matter of distance from the launcher scaling up with impulse. A conventional modroc recoving under parachute (7 ft^2-lbs/sec^2) is perfectly safe, no matter who it hits. Assuming the frangibility was as it's supposed to be, a Astron Alpha lawn darting into the top of your head (1250 ft^2-lb/sec^2 but with energy dissapating impact) will not almost certainly not kill anyone or even cause anything more than a bruise. A 50 lb HPR model descending at 40 fps (40000 ft^2-lb/sec^2) and hard as a rock) under a parachute carries a very realistic lethal capability. A 50 lb HPR model lawn darting at

400 fps (4000000 ft^2-lb/sec^2) - well, need I say it.

That's why you need some control over the range. A general rule of thumb for potentially risky professional endeavors is "one mistake does not result in serious injury or death". The range I saw does not meet that criteria. You don't use statistics - every realistic single failure mode is addressed. This includes, in this case, not looking up and dodging the descending model. I don't think this was hard to see, even with the editing.

Brett

Maybe it has something to do with:

4.19.2.5 "Pyrotechnic high power solid-pr> >