aaarg I cant find it, specs for GoFast

I believe the specs were posted on the ROL Forums.

Brian Elfert

It was an S50,000. The details were posted on ROL and on the TRA listserv.

S55k, but I got that info via email.

Ted Novak TRA#5512

Tater Schuld wrote:

The solid propellant motor contained a derivation of the propellant that I have used for my O and P motors for the past few years. The motor is designated as an S-50000 containing 435 lbs of AP based propellant configured in a monolithic case-bonded grain with a central fin-o-cyl core with a nearly neutral thrust profile. The case was aluminum 6061 with an OD of 10" and 175" long. The end closures were retained with two rows of radial bolts. The nozzle was created from a new process using a combination of graphite, carbon fiber, and ablative materials and featured a bell shaped exit cone. A number of static tests were performed on 3" and 6" hardware to characterize the propellant. A full scale static firing revealed issues with the motors end closures that were corrected for the flight motor. The propellant, known as D8, in 6" P-motor sub-scale testing had a delivered Isp of 222.6 seconds. This results in a final minimum delivered total impulse of 96,831 lb-sec. We believe that the flight motor should have had a slightly higher delivered Isp due to altitude effects and delivered just over 100,000 lb-sec.

What's "fin-o-cyl"?

I still can't get over the size of that motor, it's HUGE!

Its a core made with a cylinder with a number of fins attached. Good for density loading and controlling the thrust profile. Closest thing to it is star core as far as looks.

Pax

A cylindrical core with 4 steel fins on about the last 1/5 to 1/4 of the mandrel (that is pulled out with a press) that give a high initial thrust slug and flattens out the thrust curve a bit.

Pardon the tech post!

By comparison I make a 9" x 14" motor with about 750 pounds of propellant that is NOT non-erosiuve by virtue of a HUGE core, but by proper ballistic design.

A-Rocket mailing list?

Thanks for the info.

You make it? Where, and when did you make it, and where/when did you fly it?

Typical. We can always count on Big Fine to take a dig at the other guy's success while promoting his own vaporware.

Say what you will about his shipping practices; the motor Jerry brought out to Mojave for my rocket wasn't vaporware. (The only thing that got ripped off was a set of fiberglass fins, at an estimated 270 m/sec.)

-dave w

-snip-

Pardon my ignorance, but what are you talking about when you say non-erosiuve (or non-erosive). Are you talking about the nozzle or the fuel itself being eroded? Any info you have on this 750 pounds of propellant motor would be greatly appreciated.

Good thing you didn't use the 229mm motor!

Fuel.

Email only.

Refers to gas flow through the propellant grain core... if its velocity is high enough, it "torches off" the burning surface faster than would otherwise occur at the engine's operating pressure - which means that the engine will operate at a higher pressure. It's quite likely the cause of the startup spike seen on the thrust curves of the longer-casedd Aerotech motors.

It's less likely to happen when the core cross-section is large compared to the nozzle throat, so the gas flow doesn't have to speed up as much before it actually gets squirted out the nozzle, where it's supposed to speed up.

-dave w

I want to see the videos of the Kline/DeVille motors (ballistically calculated by Rogers) that catoed from erosivity!

I assume these were AR rocket motors? Jerry you aren't selling high power rocket motors in the PRK are you? HPR motors that hasve not been classed by the CSFM ? And what form of Pyrotechnic License do you have Jerry? Rockets

shockie B)

I don't hold a pyro license. The flight was made under the auspices of a class 1 licensee, as were the liquid propellant launches.

-dave w

Why the sudden reticence about answering a simple tech question?