Hello All,

While I rather doubt that this will ever become a NARAM event, it is intriguing to contemplate the contest possibilities of the following:

Here are links to material on lightning-triggering rockets, including model rockets (see: http://en.wikipedia.org/wiki/Lightning_rocket , https://www.google.com/search?hl=en...0.0.xLrAfSG8Vf4 , and https://www.google.com/search?hl=en...CQQsAQ&tbm=isch ). A lightning rocket can use an electrically-conductive exhaust plume (cesium salts added to the solid propellant accomplish this), or it can trail a thin wire that is connected to the ground. In addition to being used for lightning research, such systems are also used to trigger lightning in order to protect other locations from lightning strikes. Also:

Such a trailing wire could be arranged like the "flaked," boxed trailing lines that life-saving rockets trail behind them. William Schermuly devised this flaked line for his life-saving rockets (see: http://www.cyber-heritage.co.uk/schermuly/ ). Here are illustrations of the flaked boxed lines and the rockets (see: http://www.cyber-heritage.co.uk/schermuly/ake.jpg, http://www.cyber-heritage.co.uk/schermuly/ake1.jpg , http://www.cyber-heritage.co.uk/schermuly/end.jpg , and http://www.cyber-heritage.co.uk/schermuly/spa5.jpg ). This packaging method allows 3/4 of a mile of 1/2 inch circumference line to be stored in a box just 20" X 20" X 12" in size! As the very thin varnished magnet wire is far thinner than the trailing lines pulled by life-saving rockets, very long lengths of it (2,300 feet [700 meters] is a typical trailing wire length for lightning rockets) could be packaged in such a compact volume, for conducting lightning-triggering launches. In addition:

The Aerotech Mustang model rocket (see: http://www.hobbylinc.com/htm/aro/aro89010.htm ) has been used for wire-trailing lightning research flights, and I recall seeing photographs of French-made black powder rockets (not model rockets) which U.S. lightining researchers also used (the article was in a 1980s issue of "Popular Mechanics" or "Popular Science" magazine). Lighting rockets--especially those that trail wires--are launched pneumatically, because electrical ignition leads would provide an easy path for the lightning to flow right to the launch controller and electrocute the person who pushed the launch button! Instead, a length of rubber tubing runs from a pneumatic firing button to a pneumatic switch at the launch pad, as in Centuri's pneumatic "Servo-Launcher" (see: http://www.ninfinger.org/rockets/no...a/72cen052.html ). (The Servo-Launcher was developed in the days before the modern low-current model rocket igniters were invented. By using extremely short [just a few inches long, for a negligible voltage drop] firing leads, it enabled just *two* photo-flash "D" batteries, which were housed in the launch pad itself, to fire the old high-current nichrome igniters.)

I hope this material will be useful.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

It's nice to see a tiny little seed I planted grow into a small tree.

http://www.oldrocketforum.com/showp...47&postcount=28

Now when will we first see Aerotech Mustangs with short decorative wire hanging from them be entered at NARAM?

Pink Book Lawyer Jerry

Thanks to blackshire to identifying which Aerotech model was used (after Jerry's comment in the other thread). Now, as with the Enerjet 1340, we need some documentation showing that use...including at least one good picture to show color and markings. Then....it could be (I think) entered in Scale.

__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE

You're welcome (I recall seeing them years ago, but it was Peter Alway who jogged my memory). My guess is that it was LLNL (Lawrence Livermore National Laboratory, as Jerry's posted photographs are credited), since such lightning research is also relevant to plasma physics in general (for learning more about nuclear fusion, ionospheric physics, and related plasma phenomena). Googling "lightning research," "triggered lightning research," "lightning rocket," and searching on LLNL's and the Sandia National Laboratory's websites (it and LLNL might be "laboratories" [plural]) with those terms should bring up papers and articles about this work. Also:

The publisher of "Popular Science" and "Popular Mechanics" has a searchable online library of scanned issues (I forget the publisher's name, but Googling the magazines' names will bring it up--I found it by accident one night while looking up a particular article). In honor of Jerry's suggestion, 1:1 scale models of those Mustang rounds might be called "Suicide Specials"--"Go out with a blaze of glory!" :-) In addition:

Peter Alway pointed out to me that the term "flaking" (which refers to the way the life-lines of life-saving rockets are packed in their boxes, so that they can un-coil freely as the rockets pull them, as described *here* http://www.cyber-heritage.co.uk/schermuly/ [lightning rockets' trailing wires might be similarly packaged]) is incorrect. The correct word is "faking," and it--as Peter said--seems to be a standard nautical term.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

To qualify for scale it has to be a particular round. So whatever model a photo can be obtained of becomes the one.

I think those tests were done in FL.

Pink Book Lawyer Jerry

So does anyone recognize the lightning rocket on display at Chicago's Museum of Science and Industry?

http://www.msichicago.org/whats-her...esearch-rocket/

__________________
Charles McGonegal
Ciderwright
AEppelTreow Winery & Distillery
Ad Astra Tabernamque!

I've never seen one of that type. It's interesting that it carried the wire spool itself (instead of having the wire spool on the ground--the Aerotech Mustang rounds worked that way), behind its fins. When I first saw it, I wondered--before I read the text--if it was a piston for launching the rocket from a closed-breech tube launcher, like the Arcas. The three wire loops in the rocket's middle are also interesting. They might have been installed in an attempt to shield some kind of onboard instrumentation, but my guess is that they provided more "capture area" for the lightning to "grab onto," so to speak. Also:

Those loops closely resemble the capacitance hats of many shortened antennas (coil-loaded antennas that are *physically* short as compared with their operating frequencies--a capacitance hat forces more current into the upper [or far] end of a shortened antenna, making it radiate [or receive] the signal more efficiently). Such hats, being blunt rather than sharp, also help to prevent coronal discharges from the ends of such antennas from static charge build-ups (from storms, or from dry winds on clear days and nights).

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

It's on public display at the musuem - I've let my membership lapse (switched to the Shedd Aquarium) so I can't easily go and gather more details.

If I recall correctly, it's about the size of a Wildman Junior. I'd guess that it had a 38mm engine mount. -Maybe- 3" and 54mm. It wasn't very big.

73s de N8OKM

__________________
Charles McGonegal
Ciderwright
AEppelTreow Winery & Distillery
Ad Astra Tabernamque!

The Discovery Channel or the Learning Channel did a show on the study of lightning in Florida way back when they actually ran shows about science. MPR rockets trailing wire were used and were launched using plastic tubing that the scientists blew into to trigger electrical ignition. Think of a large scale Centuri Servo launch system.

This may have been covered in the threads. Sorry if it has, but I didn't have time to read through it all this morning.

__________________
I love sanding.

I've never heard of the Wildman Junior (I'm not very familiar with the bigger hobbyist rocket kits). The museum's rocket doesn't resemble any kit I've seen in AAA Model Aviation Fuels', Aerotech's, LOC Precision's, North Coast's, Public Missiles', or THOY's catalogs (but the last time I looked at any of their catalogs was over a decade ago, so many new kits have no doubt been created since then, including by other manufacturers). That lightning rocket might also have been custom-made by students for the experiment, perhaps using a stock nose cone (it looks like a 5:1 tangent ogive) and a stock body tube from a MR or HPR kit manufacturer.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR