What do these terms mean?

[raohara]

In some recent posts certain terms and acronyms were used that I am not familiar with. Rather than hijack a thread I thought I would post them here in hope that someone could explain the meaning.

1. In a motor related thread the phrase "...EX side of things" was used. What is the meaning of EX in this context?

2. In the same thread someone mentioned Pepcon. Who or what is Pepcon?

3. In another thread the acronym TARC was used. Who or what is TARC?

- Rich

[Doug Sams]

In some recent posts certain terms and acronyms were used that I am not familiar with. Rather than hijack a thread I thought I would post them here in hope that someone could explain the meaning.

1. In a motor related thread the phrase "...EX side of things" was used. What is the meaning of EX in this context?

2. In the same thread someone mentioned Pepcon. Who or what is Pepcon?

3. In another thread the acronym TARC was used. Who or what is TARC?

- RichEX is referring to experimental motors, usually in the context of TRA's EX program (now called "research"), which are predominantly APCP motors, but other chemistries are allowed.

Pepcon was a facility in a western state (Nevada?) where a huge amount of AP was in a fire. At high temperatures, AP (not APCP) becomes a mono-propellant and can essentially explode, which it did in this case.

TARC is Team America Rocketry Challenge, a program for youths to compete for a big time prize at the national level. A generic example is flying an egg to 900 feet and returing it intact with an overall flight/descent duration of 1 minute. Points off for going over/under 900', and for going over/under 60 seconds. It's tough competition, but kids can get scholarships out of the deal, I believe.

HTH.

Doug

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[raohara]

Yes, helps a lot. Thanks Doug.

[Bazookadale]

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TARC is Team America Rocketry Challenge, a program for youths to compete for a big time prize at the national level. A generic example is flying an egg to 900 feet and returing it intact with an overall flight/descent duration of 1 minute. Points off for going over/under 900', and for going over/under 60 seconds. It's tough competition, but kids can get scholarships out of the deal, I believe.

HTH.

Doug

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There are $60,000 in prizes split I believe among the top 10 . In addition the winning team gets a trip to Europe, in this case the Farnborough air show outside of London. This year the Penn Manor team #1 won TARC and won the international rocketry challenge! Info on TARC can be found a t www.rocketcontest.org

And here is a nice piece on the Penn Manor team

http://www.fox43.com/videobeta/0d7ee74a-5419-47da-826c-5d3aa15cfba9/News/7-27-Penn-Manor-Students-place-First-in-the-Transatlantic-Rocketry-Challenge

[CPMcGraw]

...And here's a video clip of PEPCON...

YouTube Link (http://www.youtube.com/watch?v=_KuGizBjDXo&feature=fvw)

[Digitalastro]

I remember the PEPCON explosion. I was stationed at Nellis AFB which is about 20 miles away. At that time I worked midnights and was sleeping. It shook my bed enough to wake me up. I thought that a jet had crashed on base. The explosion took out the Kidd marshmallow factory across the street.

[raohara]

... which are predominantly APCP motors, but other chemistries are allowed.
Other chemistries?? I've only heard of BP and APCP. What else is there? Does anyone manufacture a commerical model rocket motor made with "other chemistries?"

- Rich

[Doug Sams]

Other chemistries?? I've only heard of BP and APCP. What else is there? Does anyone manufacture a commerical model rocket motor made with "other chemistries?"Other types include zinc-sulfur, sugar-motors and ANCP (ammonium nitrate). Not sure if all these are allowed under TRA's program.

I'm not aware of any pre-made motors of these type, but I think there are some kits (sorta like a cake mix :) ).

One interesting thing I've learned about all this is that the danger involved is inversely proportional to the specific impulse (Isp), the woosh per pound of propellant. BP is the most dangerous followed by zinc-sulfur then sugar motors, then APCP. Yet, APCP offers the highest Isp motors. And it's extremely durable in storage. So, if I ever get into making my own, I'll do APCP for the safety factor.

Doug

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[Shreadvector]

And another question is: what is Google?


http://www.google.com/search?hl=en&q=pepcon&btnG=Google+Search

http://www.google.com/search?hl=en&q=tarc&btnG=Google+Search

http://www.google.com/search?hl=en&q=ex%20rocketry&btnG=Google+Search

[ghrocketman]

Sugar motors are allowed at TRA research launches. Not sure about ANCP, but pretty sure Zinc-Sulphur is banned.

[pantherjon]

Sugar motors are allowed at TRA research launches. Not sure about ANCP, but pretty sure Zinc-Sulphur is banned.

You are correct..Zinc-sulfur motors are not allowed..

5.3. Additional Prohibited Propellants
5.3.1. The following propellants shall also be excluded from Tripoli Research launches: double and triple-based propellants, and micro-grain propellants, including zinc/sulfur
propellants.

From here (http://www.tripoli.org/LinkClick.aspx?fileticket=YnzHZzIyiPE%3d&tabid=86)

[ghrocketman]

Wonder why the ban on double and triple-based propellants ?
Correct me if I'm wrong but are those not some of the more energetic propellants used in military missile applications ?
Seems those would be PERFECT for research.
Agree with the ban on Zinc-Sulphur though...that stuff is nothing more than a menacing hazard that has been proven time and time again.

[Jerry Irvine]

I have flown lots of zinc-sulfur rockets and I can spell it too. They require different methods and precautions that are incompatible with a consumer launch. You need to use a steel tube for the motor case and you need to have blast protection and overhead protection to be adequately safe. All those facilities exist at two sites in California where zinc-sulfur rockets (and sugar rockets) are fired all the time.

I flew one 5" Z-S rocket with Dave Griffith and Mike Smalley in the 70's. It was truly cool. I saw a film, yes film not video, of a Z-S motor attached to a telephone pole which made it the largest stick rocket I had ever seen.

I saw a 1.5" diameter sugar rocket explode. It was attached to an 8x8" wood pillar. The pillar was reduced to matchsticks.

One needs a blockhouse and thick steel and concrete safety barriers for some forms of rockets. Attached is a photo of a sugar rocket static test set-up with the underground blockhouse visible. It has 2" thick plexiglass windows in those thin slots and well over a foot of steel reinforced concrete roof. You could launch an APCP "S" motor from, or into it, and not phase it.

Jerry

http://www.rrs.org/main.1.0/images/projectimages/photo09.jpg
A Zinc-Sulfur rocket being flown from Mojave Test Area hosted by RRS.

[ghrocketman]

Sulphur is the TRADITIONAL non-modernized spelling, Sulfur is more modern. NEITHER is incorrect. Another example is Grey=Gray.
The more common spelling of Sulfuric Acid changed from Sulphuric Acid actually much later.
I wondered who the first smart-aleck would be to comment on my spelling and now I know, but am surprised. I thought for SURE it would be a particular member located in california also, but not you Jerry.

ANY form of rocketry that requires large reinforced blockhouse structures is WAAAAYYYY too much hassle for me. Especially when APCP has higher delivered impulse per gram.

[Jerry Irvine]

I wondered who the first smart-aleck would be to comment on my spelling and now I know, but am surprised. I thought for SURE it would be a particular member located in california also, but not you Jerry.

ANY form of rocketry that requires large reinforced blockhouse structures is WAAAAYYYY too much hassle for me. Especially when APCP has higher delivered impulse per gram.
I said *I* know how to spell, not that anybody else did not. :D

Once someone did all the work of buying, licensing, and upgrading a facility for Z-S and "Sugar" rockets, it became trivial for others to just show up and fly. Besides it's only about 2 hours from Disneyland and Knott's Berry Farm. Mmmmmm, chicken dinners.

Jerry

APCP bigot.

[Shreadvector]

I said *I* know how to spell, not that anybody else did not. :D

Once someone did all the work of buying, licensing, and upgrading a facility for Z-S and "Sugar" rockets, it became trivial for others to just show up and fly. Besides it's only about 2 hours from Disneyland and Knott's Berry Farm. Mmmmmm, chicken dinners.

Jerry

APCP bigot.

Spelling and chicken = http://www.eatmorchikin.com/

[tbzep]

You are correct..Zinc-sulfur motors are not allowed..

5.3. Additional Prohibited Propellants
5.3.1. The following propellants shall also be excluded from Tripoli Research launches: double and triple-based propellants, and micro-grain propellants, including zinc/sulfur
propellants.

From here (http://www.tripoli.org/LinkClick.aspx?fileticket=YnzHZzIyiPE%3d&tabid=86)

The reason I mentioned Pepcon is because they were our source for AP. IIRC, it happened in 1988. When the plant went up, our home grown source of AP went also. AP eventually got scarce and expensive. We ended up importing Chinese AP to fill the rocketry hobby niche.

[Mark II]

Many people on this forum know much more about this than I do, but here is a pretty good summary of the "PEPCON disaster (http://en.wikipedia.org/wiki/PEPCON_disaster)." And this is where I need more information, too. The article gives the date as May 4, 1988. Wasn't there also some fire or explosion at another solid propellant manufacturing plant in 2000 or 2001?

[Mark II]

The reason I mentioned Pepcon is because they were our source for AP. IIRC, it happened in 1988. When the plant went up, our home grown source of AP went also. AP eventually got scarce and expensive. We ended up importing Chinese AP to fill the rocketry hobby niche.Isn't Canada another significant producer of AP? Also, has US production of it recovered since 1988?

[tbzep]

Isn't Canada another significant producer of AP? Also, has US production of it recovered since 1988?

I don't know. I just know that the AP we used after Pepcon came from China. I got out of HPR entirely not too long after 9/11, so I don't know where any of it comes from now.

[ghrocketman]

Anytime there is some sort of disaster be it minor or major, the gubmint usually reacts by going WAY overboard with knee-jerk reactionary asinine jack-booted gestapo OVER-REGULATION.