[tccrockets] Re: DairyAire 2012 Nike Smoke Drag Race
- From: "Jimmy F" <Aldocyber3@xxxxxxx>
- To: <tccrockets@xxxxxxxxxxxxx>
- Date: Sun, 22 Apr 2012 15:52:42 -0700
I’ll go first,
But you must realize I win course my rocket left the pad first.
Jimmy F.
TRA 12524
From: 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] 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"
No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.455 / Virus Database: 271.1.1/4947 - Release Date: 04/19/12
18:34:00
Other related posts:
