[tccrockets] Re: DairyAire 2012 Nike Smoke Drag Race
- From: "AiRobert" <airobert@xxxxxxxxxxxxx>
- To: <tccrockets@xxxxxxxxxxxxx>
- Date: Sun, 22 Apr 2012 16:04:20 -0700
Well the real problem is if NFPA adopts it we all will adopt it, so we need
to convince NFPA to not adopt it. Then each group can do their own thing.
@James Thanks for bringing the goats into this..
RZ
_____
From: tccrockets-bounce@xxxxxxxxxxxxx
[mailto:tccrockets-bounce@xxxxxxxxxxxxx] On Behalf Of James Dougherty
Sent: Sunday, April 22, 2012 3:42 PM
To: tccrockets@xxxxxxxxxxxxx
Subject: [tccrockets] Re: DairyAire 2012 Nike Smoke Drag Race
Thanks Jack
Yeah, that is a pragmatic rule based on shear rigor to mathematical formula.
As someone explained it, they are considering ballistic recovery inside a
cone with .5x as the standard deviation for +/- outside of the cone (like a
cluster). If you do a "Monte Carlo" simulation you can show the likelihood
of ballistic kill is less by simply increasing the radii of the launch site.
So, it will make it safer, but unfortunately this decreases failure
probability only a small amount and adds lesser value then a common build
and rocket inspection under guidance of the RSO and LCO (which prevail as is
already written in NFPA 1127).
To prove my point, here's a twist on this. Supposing we had a drag race
where:
0) All of the rockets were the same kit, and inspected during construction.
ONE person built
all the motors (and was an expert for that motor build and known to
build/fly it correctly).
1) All of the rockets were inspected by the SAME RSO/LCO and were deemed
safe to fly - a metric 0-10 with 10 the most likely. Further, all rockets to
fly were deemed a 10 for flight/recovery.
2) We let everyone pick their launch pad, load their rockets, and point
straight up
3) We used ONE rocket, graded 10, located in the center, and fired that
rocket (alone) FIRST before the Drag (also pointed straight up).
4) Everyone went back with the same RSO/LCO and double checked their rocket
and possibly changed their launch angle. The KEY is that they must at least
double check.
5) We all launch the rockets
This can be shown to have a higher probability of success then just
increasing the launch site to cater for failures - the reason is because It
can be shown that this is a conditional probability A where A is the
observance of a safe flight of a set of rockets all built the same and B the
event where the single safe rocket launch was observed first. What's even
more interesting is that even if the launch of the sample A was not a
successful launch, so long as everyone double checked their rocket, the
probability of success would still be higher then not observing the first
flight with the same setup.
People may say "well, that's just common sense ..." , but actually it's not.
It's the foundation of the classical Monty Hall paradox (Price is Right
winning strategy) and part of the reason NASA launched Nike Smokes and
studied their trajectory before the main Saturn launches... higher
probability of success once seeing a working example.
I vote we use the same safety inspection procedure as last time, but then we
fly one first, go
back and double check before mass launch.
One good proposal for mass launches would be to leverage conditional
probability by a) having a mass build session, b) mass inspection of the
rockets by the same standards and c) fire a test flight of a rocket built to
the same spec before d) mass launch.
Anyhow, this is a controversial topic and the above can be warped into
actually creating a counter-argument to why the MSD should be changed - it
is only a proof that the observance of the occurence of an event can
statistically change the outcome of another -- didn't realize our brains are
actually doing math behind the scenes did you :-)
There are good Wiki articles on it here:
http://en.wikipedia.org/wiki/Monty_Hall_problem
http://en.wikipedia.org/wiki/Conditional_probability
-James
On Sun, Apr 22, 2012 at 2:44 PM, Jack Garibaldi <jackgaribaldi@xxxxxxx>
wrote:
It is premature Robert NAR (Trip Barber) is not for mass launches and has or
is or did submit a new ruling to the NFPA basically saying that ten and
over or over ten rockets launched simitaneously should be at a safe distance
of 1.5 times the expected altitude so if we had 11 Nike's and they all were
expected to do about 7,000ft then the safe distance required to launch them
would be 10,500 ft. It is way too early to start worrying but the thought is
that if it gets adopted by the NFPA well then Tripoli would probably adopt
it too because a lot of people don't really care or do mass launches but the
few that do would be screwed like us and a few other clubs. Take Plaster
Blaster they always do a fun launch for the kids and give out T-shirts and
candy by doing a 100 Estes quirks or alpha's or some small rocket that the
kids can go run and retrieve and get paid in Candy or prizes well if they
were going to go 1,000ft the the safe distance would have to be launched at
1,500ft and then no one can even see them at that distance. In general Trip
just doesn't like, agree or want mass launching.
Jack G
From: tccrockets-bounce@xxxxxxxxxxxxx
[mailto:tccrockets-bounce@xxxxxxxxxxxxx] On Behalf Of AiRobert
Sent: Sunday, April 22, 2012 2:34 PM
To: tccrockets@xxxxxxxxxxxxx
Subject: [tccrockets] Re: DairyAire 2012 Nike Smoke Drag Race
I must be out of the loop, why the last time?
I'm in for something, any requirements?
RZ
_____
From: tccrockets-bounce@xxxxxxxxxxxxx
[mailto:tccrockets-bounce@xxxxxxxxxxxxx]
<mailto:%5bmailto:tccrockets-bounce@xxxxxxxxxxxxx%5d> On Behalf Of James
Dougherty
Sent: Sunday, April 22, 2012 1:13 PM
To: TCC chat
Subject: [tccrockets] DairyAire 2012 Nike Smoke Drag Race
Guys,
Since this may be the last year we're ever able to do mass drag race again.
Who's in?
I'll be using PR Nike Smoke 4" with K2045 ...
Here's an updated image:
The latin on the bottom "Novissimo tempore volavit milspec" translated
literally means
"the last time we flew milspec"
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