NEFAR Launch 5-05

NEFAR Launch
May 14th and 15th 2005

A team approach for sugar motors
And a novel smoke-grain configuration

Prior to this two-day event, I wrote the officers of NEFAR, asking if anyone would want to be part of a "team" where I would provide the motor, they would provide the airframe. Some responded affirmatively, so I made as many loads as I could - six for the 54mm Loki casing, and five for the 38-720 Dr. Rocket casing.

They were moonburners. I have learned to like this grain, as it gives adequate thrust with a much longer burn than a Bates grain design. Most of these motors included about 3% fine flake titanium in the propellant, providing a little sparkle for the white smoke trail.

(Click for details)

And some used the "labyrinth" smoke grain. This is an attempt to get long-burning smoke from a short grain while using fast-burning KN/sucrose as the smoke charge.

It worked well on the two launches where it was used: my Sugar Rush and on Scott Borders' first launch, providing good smoke even a few seconds after parachute ejection. The conventional end-burning smoke grain worked OK on Mike Kiss' launch, but burned out too soon on Scott's second launch.

Here are the launches, in approximate chronological order.
Some of them had nothing to do with my propellant, but are worthy anyway!

Gary Dahlke - Mixed grain, white lightning/blackjack 5/14/05 (4.3 meg .wmv file, 1:34 - one minute, 34 seconds)

At the last NEFAR launch in April, Gary had launched a rocket using this mix, with striking effect. The smoke trail assumed a "checkerboard" pattern, alternating dark and light smoke. I couldn't imagine how this would happen, and so was delighted when Gary was willing to try it again. This time, the grains were arranged differently, and the pattern was not as obvious. But you can still see some sections of light and dark alternating toward the end of the burn. Anyone know why this happens?

Steve Pollock - Fantasy Jr. Flying on an I-205. (3 meg .wmv file, 0:52) Beautiful rocket, nice flight!

Jimmy -Yellow Dog 1 - First Launch, 5/14/05, altitude 1924 feet (1.4 meg, .wmv file, 0:28)

The trusty Ariel is now flourescent camo yellow, with brown spots all over its month-old paint job. It is still highly visible, and that is what I want. My CPR-3000 altimeter has been a bit flaky lately, so I am using this as an opportunity to test it in a non-critical situation. I hope to fire the Sugar Rush with it tomorrow, and would rather not have it fail then. The altimeter is placed in the payload bay, padded with bubble-wrap. It is armed with two Jimmyfire ignitors, just a touch of Red Dot in each one - just enough to create a scorch-mark so I will know if they fired. Side benefit is that it should give me an altitude reading.

Secondary payload: I placed a film-can full of Christmas-tree-bulb ematches in the payload section too. I want to loft them several times, then test them on the ground and see how many fail. This to determine if they can handle the stress of a launch reliably.

Greg Lukach - Static Test 1, 5/14/05 (1 meg .wmv file, 0:15)

Steve Ghioto - Static Test 1, 5/14/05 (2 meg .wmv file, 0:30)

Bill Stafford - Launch with Dr. Rocket 38-720 motor, Ti-Rcandy, motor ejection 5/15/05 (3.7 meg .wmv file, 0:57)

This flight used a 2-inch delay grain for ejection purposes. Thankfully, it worked OK. Then again, I have not had an ejection failure with these grains so far, and the only two that failed in static testing involved a problem that I think is solved: ejection charge moving away from the delay grain. Solution? Tuck a little black powder in the head end of the delay grain well before pressing the grain all the way home. The grain itself thus holds a little BP in its grasp, which makes a spurt of flame when it burns through.

Apologies that I lost the rocket in the video and did not track it to apogee. Apparently it did OK, according to comments from the audience.

Steve Ghioto - Experimental motor launch, AN/Epoxy (1.7 meg .wmv file, 0:30)

Jimmy - Yellow Dog 2 - Second Launch, Dr. Rocket 38-720 motor, Ti-Rcandy, motor ejection, 5/15/05 (2.1 meg .wmv file, 42 seconds)

Similar to first launch, but without altimeter. Steve Ghioto had kindly done a bit of troubleshooting on the altimeter yesterday, and discovered that one of the battery connectors was loose, causing intermittent operation. I soldered it that night, making it much more solid. So much so that the altimeter is now resting in the Sugar Rush beeping on Pad 10.

Jimmy - Sugar Rush - One and only launch this trip, 54mm Loki motor, moonburner, plain Rcandy with no Ti. (13.1 meg .wmv file, includes recovery 3:45)

The simulation had indicated apogee would occur at 3600 feet, but the altimeter beeped out 3236. In reviewing this video, I notice that the rocket descended a bit before firing the ejection charge. I suspect that the altimeter "locks in" the apogee reading just before firing the charge, so this rocket may have gone a bit higher.

Main at apogee. Again. I thought I had fixed that problem. Good thing the wind was low, it landed on the field about 1/4 mile away. While driving home, the idiot light started flashing in my head. I'd heard a little "pop" when then rocket descended to about 600 feet, where main was supposed to deploy. Had I wired the ematches backward? Stopped for gas, checked it out, and yes, I'd wired the forward charge to the drogue terminals. I am a fool. Why am I driving this truck? Teresa takes over driving, I stare at the road.

(Click small picture for larger one)

David Koscielniak - Two stage yellow/black rocket. (14 meg crudely edited .mpg file, 1:23) I was out recovering the Sugar Rush when this one fired. Shame on me. It was a beautiful flight! It doesn't show in the low-quality video, but in the high-quality version, one can see the rocket arcing over the puffly little cloud in mid-screen. Shortly after the smoke trail disappears from view, it reappears out of the top-middle of the cloud, arcs up a little
ways, then descends in a graceful sweep around the right side. There is a loudish "pop" heard at one minute into the video, which I suspect to be the recovery of the booster. Another fainter "pop" is heard at 1:06, which I believe to be the drogue ejection. Then I got distracted again with my own rocket. More shame.

Mike Kiss - Thor, 54mm Loki motor, moonburner, Ti-Rcandy (4.3 meg .wmv file, 1:33)

Using a 7.5 inch moonburner grain with 3% Ti. The conventional end-burning smoke grain is 2 inches long - it worked well on this launch, the smoke grain finishing up right at apogee.

Greg Lukach - Static Test 2, 5/15/05 (1.2 meg .wmv file, 18 seconds)

Scott Borders - 54mm Loki motor, moonburner, Ti-Rcandy (10 meg .wmv file, 3:03)

This launch used the labyrinth smoke grain, which produced well and burned for a few seconds after ejection. Altimeter beeps 2539 feet.

Gary Dahlke - "Pepperoni" launch 5/15/05 (6 meg .wmv file, 1:54) Another classic flight.

Scott Borders - 54mm Loki motor, moonburner, Scott's second flight with Ti-Rcandy (2 meg .wmv file, 42 seconds )

"We almost gottim!" Conventional end-burning delay grain, 2 inches long, did not burn all the way to apogee. I lost track of the rocket before ejection occurred, but was able to track the commercial aircraft well.

Jimmy - Yellow Dog 3 - Third launch - one more time. (7.7 meg .wmv file, 0:37 seconds) Essentially the same deal as the second launch, with much the same results. No altimeter this time either, but it looks like it went up aways, then came all the way back down.

I would call this launch a success. All motors worked, ejection functioned adequately, if not always optimally. To see seven of my motors fly in a single day is unreal.
To quote Mike Kiss: "I like it!"

Words can hardly express my appreciation to Bill, Mike and Scott who were willing to put their airframes at risk to test my motors and loads. And to the officers and folks of NEFAR who made it all possible.

I am relieved and proud that all worked OK, and look forward to another round next month!

Jimmy Yawn
Recrystallized Rocketry
rev. 6/5/05
jyawn@sfcc.net