5.5" Nike Smoke

Flight #1, April 2005

OK, I'm gonna be a bit more verbose than usual.  It's a good story.  I think.

At the end of January, we cast up a 4700 Ns L motor using the famous "White Trash" formula from MDRA.  This was supposed to go into Eric Williams' 7.6" upscale Sumo that he's been working on for a while. But the week before its planned launch, a frantic e-mail was sent... "I ran out of epoxy. Bring This End UP and we'll put it in that." As you might know (depending on how little of a life you have and/or how much of this website you've read), This End UP made my first M flight two years ago at ROCStock on an M1419W and hasn't been touched since. When I pulled it out of the rafters to begin assembling it, a myriad of problems cropped up - the 98/75 adapter didn't fit right, the avionics had to be reworked, and some other nasties. As the week drew to a close, it became apparent that we couldn't fly This End UP on the L motor. We both really, really wanted to see this motor burn in a rocket, because static tests get old after a while, and an L motor would be quite the waste.

Packing up on Friday, I put the brand new 5.5" Nike Smoke into the car. I had just painted it the night before (frantically) and was pristine - not a blemish on the finish.  We couldn't help but notice the 76mm mount that I had installed to hopefully burn up some of the 3-grain motors that we have been making. The first flight was planned to be on a 54mm 1440 Ns K700 the next day, to get the rocket in the air and make sure it functioned.

You can see where this went.

So late in the morning, Eric and I finished prep on the brand new, virgin, unflown Nike Smoke, with a 4700 Ns White L motor in the back end of the rocket. As this was a dual-deploy version of the Nike, a 6000 case won't fit. Great, we're flying the rocket for its first flight with a brand new motor that's the largest thing that fits in it. It's rocketry, what could go wrong?

We put it on the pad, and after arming electronics, installed a Thermite igniter 2/3 of the way up the back end of the motor, hoping to get it off the pad nice and quick. Check for aircraft, and announce the flight. We're the biggest thing at the launch today. 5...4...3...2...1... I slam down the button.
BOOM!

The Thermite goes off and the rocket leaves the ground... and travels 6" up the rail, stops, and slams back down onto the rail support. Um, ok? It didn't light it. There was a nice circle of copper on the ground underneath the motor from the reaction, though. What happened? Current theories are that the motor snuffed itself out when the Thermite went out, or possibly humid conditions corrupting the perfect scratched up cores of the motor.

But we can't let that be the end of our story. Neither of the on-board avionics units had armed, so we decided to load it up with a "satan spawn" igniter. Our friends, Peter and Steve over at LEO, have been developing an igniter for their PSAN motors.  PSAN is HARD to light, but in their tests, 10/10 motors have lit so far, instantly, the first time. Hey, it should work for our AP-based motor just fine!  So we took one of these igniters and tied about 10g of shavings from blue propellant onto the head with dental floss.  With all the propellant and the untrimmed dental floss hanging off, you can get some image of where the name came from.  I shoved it all the way to the head end of the motor. It barely fit through the nozzle end of the motor with all that propellant on it.

I began the long walk back to the rangehead, leaving Eric by the pad to start the PadCam and get the heck out of the way. We were both nervous this time - what if the motor CATOed? What if the rocket shredded? It was it's first flight, and it was awfully pretty... maybe I shouldn't push the button.

Then the rocket gods spoke in chorus: "Silence you fool! It's time to put up or shut up!". (thanks, Ed Holland.)

And so it goes. 5...4...3...2...1... I pushed the magic mystery button.  Immediately, blue fire began to pour from the base of the rocket as the igniter tried with all its might to light the motor.  "Here we gooooo," I thought.  Finally, after two seconds of burning, the motor came to life.  Oh.  My.  God.  My poor Nike didn't stand a chance against that motor.  It jumped off the rail and headed dead straight into the sky. No roll. No wiggles. That L motor took 22 lbs of loaded rocket and slammed it into the air like it was a rag doll. As the motor kept burning and burning, I was praying in the back of my head: "Please hold through Max Q. Please hold through Max Q."  The motor was slightly progressive, so the rocket continued to pick up speed before trailing off. Finally, the magical moment arrived and the motor shut down. I let out a sigh of relief that sounded more like Howard Dean at a campaign rally. We had done it, our first L motor worked perfectly. Now there was nothing left to do but cross my fingers and let the altimeters do the work. The rocket continued going up for ages, easily tracked thanks to the 1" bulkhead smoke grain we had cast up. Finally, a glint of sunlight reflected off the airframe as she arced over, and one of the two avionics units popped the drogue out. I guess 4g was a little bit much charge, because shortly afterwards the main appeared. In the haste of prep, I elected not to shear pin the nose - oh well, more time to enjoy the descent.

Eric and I walked out to recover the rocket about a mile away, easily visible on the lakebed. The RRC unit beeped out 10,122 feet, and the ARTS beeped 9521 from the undamaged rocket. Data that was later downloaded revealed a max acceleration altitude of 10,623 feet and a maximum velocity of 1107 feet/second - toying with Mach. A pressure spike is clearly visible on the barometric graph, so it looks like we may have busted the wall at MET 3.5ish seconds. The curve came out beautifully, with a nice ramp up, slight progression, and tail off to a MECO of 4 seconds. What a great motor.

There was only one problem with the flight: now all those three-grain motors are gonna be BORING!

Oops.  Too much thermite.