Rocketry Planet

CEDAR CITY, Utah USA — The National Association of Rocketry (NAR) Standards & Testing Committee has certified a new endburning motor using AeroTech's Warp-9 propellant, the G69N-P (P/N 07069P).

AeroTech's new G69N end-burner profile.

The G69N is the most powerful solid propellant motor available without an ATF Low Explosives User Permit (LEUP). Designed for AeroTech, Dr. Rocket and Rouse-Tech RMS-38/120 hardware, the G69N produces a certified total impulse of 137 N-sec with a burn time of just under 2 seconds. The delivered specific impulse (Isp) of the G69N is 224 seconds.

The G69N's exceptional performance was achieved through a combination of design features, including the use of 62.2 grams of high efficiency Warp-9 propellant with a constant burning surface area, high chamber pressure, high expansion ratio and a "bell"-shaped nozzle.

Warp-9 reloads are currently sold in a plugged configuration and rockets using them must employ a timer, altimeter or radio-actuated recovery system. The AeroTech EFC-1™ Electronic Forward Closure™ is perfect for use with the G69N when combined with the EFC38-1 motor closure.

The G69N reload kit will be priced at $19.95 each. No user certification is necessary to purchase the G69N, though customers must be at least 18 years of age. AeroTech is now accepting dealer-direct orders for the new G69N, and a limited number of reloads are available for immediate shipment.

An assembly drawing, instructions and the NAR certification document for the G69N are available for download in PDF format from the Resource Library on the AeroTech website at http://www.aerotech-rocketry.com/.  A thrust profile is available in Adobe PDF format.

AeroTech Consumer Aerospace is a division of RCS Rocket Motor Components, Inc., Cedar City, UT.

Reader comments

#1

I wonder what two of those in a 38-240 case would do?

crontab on 03-27-2007 04:32 PM

#2

This looks like an interesting motor for a couple of reasons.

It might be useful to better illustrate the difference between measurement of burn rate of APCP versus the effect of grain geometry on burn time for a rocket motor. The ATF stated in their most recent filings that many ways exist to measure burn rate, but that ignores the fact that burn rate as requested by the judge was as a material property to demonstrate that a material (in this case APCP) should or should not be considered to deflagrate.

Measuring the length of time of an end burner such as this motor divided by the length of the single grain (which I don't know) by that time (just under 2 seconds from the thrust curve) would seem to me to better illustrate the material property of burn rate (at least for the Warp 9 propellant).

Also, I am interested in seeing the "bell nozzle" they use. I'll pick one up when they are availabel and fly it.

Steve_Shannon on 03-28-2007 08:36 AM

#3 G69N

Quote:

I wonder what two of those in a 38-240 case would do?

Most likely CATO on the pad.

jrcoxx on 04-03-2007 10:50 PM

#4

Quote:

Most likely CATO on the pad.

Why do you say that? It's an end burner, so it's not going to be building up more chamber pressure because it's got two grains instead of one.

crontab on 04-03-2007 11:07 PM

#5

Quote:

Why do you say that? It's an end burner, so it's not going to be building up more chamber pressure because it's got two grains instead of one.

The TARC team I mentor had an event last week that probably happened because one of the team unscrewed the forward closure slightly to start the aft closure and then neglected to tighten the forward closure. As a result the motor disassembled and extinguished itself immediately upon ignition. Although it was not an end burner, the spirals on the outside of the propellant grain liner were obviously involved in the combustion pattern (it's kind of cool to see). I thinik that if you were to put two of these end burning grains into one case (apart from the fact that neither HP nor Research safety codes would allow it at a sanctioned launch) the combustion would proceed along the outside of the liner and ignite the end of the second end burning grain. If that happened, both grains would end up "end burning" at the same time, which would raise the internal pressure above that of a single grain. I don't know that it would cause a CATO because the Warp 9 does not cause CATOs in their other grain configurations, they just burn faster (a lot faster).

Steve_Shannon on 04-08-2007 08:02 AM

#6

I have to believe that combustion in the spiral zone would not sustain sufficient pressure in the grain area above the combustion chamber to effect a CATO.

ddmobley on 04-08-2007 02:16 PM

#7

I think this falls under the heading:
Do not try this at home!

Raider Rocketry on 04-09-2007 12:47 AM

#8

Quote:

Why do you say that? It's an end burner, so it's not going to be building up more chamber pressure because it's got two grains instead of one.

Just guessing here but the biggest issue might be the erosion of the liner just above the nozzle. With the longer burn time it would be subjected to twice as much heat. If you try it let us know what happens. It would make for a pretty cool little motor if it works.

Andrew

agrippo on 04-09-2007 10:29 AM

#9

Quote:

Just guessing here but the biggest issue might be the erosion of the liner just above the nozzle.

I wonder what would happen if you used one grain from the end burner and another grain from a core burner? That might speed up the burn enough to reduce the hot spot at the rear of the liner that you commented on.

ddmobley on 04-09-2007 03:11 PM

#10

Well if you want to get a heavy rocket accelerating quickly to a slow speed that would be one way to do it. I'm not advising it, I'm just sayin'.

Raider Rocketry on 04-10-2007 10:14 AM

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