I (Vern) only flew two rockets at the launch this year.  Starfire and Vulcan.  I had others ready to fly but the winds on Sunday afternoon and Monday morning kept them grounded.  On Saturday I launched Starfire on an AMW M2500 "Green Gorilla" motor along with six out-board J420 Redline motors as air starts.  All of the details are presented below.  Starfire reached 6,961 feet and was recovered with no damage.   It took all day to get Starfire prepped, launched and recovered. Partly because the 'away cell' was so busy on Saturday.  Due to the close proximity of the FITS launch site to the town of Mansfield, all of the larger projects had to fly from an away pad.  This is most definitely the right thing to do.  However, demand for the away cell was very high on Saturday. At least I got to watch a lot of great projects go up as I prepped Starfire.  The away cell was definitely a good place to hang out all day Saturday.

On Sunday I launched Vulcan on an Aerotech M1297 motor.  Vulcan reached 8,502 feet and was also recovered with no damage.  This was the 25^th flight of Vulcan but only the second time it has ever flown on an M-motor. 

The weather changed on Sunday afternoon and it became very windy.   In fact, the launch shut down when winds went past 20 mph.  On Monday morning it was still fairly windy, so I decided to begin packing up or the long drive home.  Of course, once everything was packed away the wind died and the rest of the day was quite nice.  Still, I decided to save the rest of my flights since we were having a local launch in Idaho the next weekend.    It's certainly nice to have so many options.  Are we having fun yet? 

This was definitely another great FITS launch.  It was well organized, safely run, had many awesome flights and lots of great people to meet.  A special thanks goes out to the launch directors for their tireless efforts to make this launch such a huge success.  And a big thank you to ALL the Washington Aerospace club members that volunteered and helped run the event.  It really was exceptional! 

Photo by Vern Knowles

This view is looking east from the top of a small hill next to the FITS camping area.  It was taken on Sunday about mid morning. The launch pads are just out of sight inside the oval dirt race track seen on the left hand edge of this photo. 

Click here to see a large high resolution image.    (1.1 MB file.)

Click here to see a smaller low resolution image.  (200 KB file.)

Now that the six J420 out-boards have been completed it is time to assemble the big M2500 motor. The 75mm AMW M2500 uses five grains, one of which is slightly longer and has a larger diameter core than the others. That grain goes closest to the nozzle.  The nozzle is a large piece of machined graphite.  The nozzle and the forward closure are held inside the motor tube with steel snap rings.  Assembly is very straight forward.

Now that the booster section is complete it is time to power-up the cameras and get them installed inside Starfire.  This photo shows the camera module that carries two Canon 4M pixel  digital still cameras.  These cameras ride inside the forward payload bay on the way up and then are deployed at apogee and take pictures during the ride down on the parachute.  

After the camera module was installed into the forward payload bay, it was time to connect and install the nose cone.  Fully loaded Starfire was about 80 pounds ready to fly.

Starfire lifted off very nicely on the M2500 Green Gorilla motor.  This motor burns for about 3.1 seconds and produces 670 pounds of peak thrust.  The on-board timer was set to fire the first set of three out-boards at four seconds into the flight.  Unfortunately, those three motors never lit.  It was later discovered that they never lit because of an electrical short in two of the igniter leads.  More details about that problem are presented below. The rest of the flight was nominal.  The second set of three air-starts lit at seven seconds into the flight just as planned.  Starfire reached apogee at 6,961 feet above the ground and deployed the main parachute.  A short while later the nose cone dropped as planned and deployed the cameras.  Starfire drifted back down and was recovered without damage.  I was able to drive to within about 600-700 yards of the landing site.  Dave Bradley helped me recover it and carry it back to the car.  Thanks Dave!

Photos of other Starfire flights can be found here.

Failure Analysis Results

The first set of three air start motors was supposed to ignite at four seconds after lift off.  That didn't happen.  After the flight I carefully checked the timers and wiring and discovered that the failure was due to an electrical short in two of the igniter leads.  The short occurred at a solder joint where I spliced the igniter leads to an additional length of wire.  Turns out the igniter leads are not long enough to reach all the way from the motors to the timer in the booster electronics bay.  So as usual I soldered an extra length of wire onto the leads.  Each solder joint was then covered with heat shrink tubing.  However, this time I happened to use a new type of heat shrink tubing.  It is thicker than what I have used on previous flights and it also seems to contract more tightly when heated with the hot air gun. The combination of pressure from the contraction and heat from the hot air gun allowed the metal solder joint to come into contact with an adjacent wire by melting through the insulation on the adjacent wire that was inside that same piece of shrink tubing.   A photo of the connection (after the shrink tubing was removed) is shown below.  The spot in the adjacent lead where the short occurred is indicated by the red arrow.  It would have been better to put the shrink tubing around only the wire with the solder joint.  For various reasons that was not done and of course it has worked fine on previous flights.  However, that will now be changed for all future flights.

The photo at the left shows the main FITS flight line and camping area.  The launch pads are set up inside the oval dirt race track.  There are three small ponds back behind in the distance.  This view is looking almost due south.

Starfire carries a Sanyo digital video camera in the booster electronics bay. 

This on-board video will allow you to see what it is like to ride along with Starfire.  The M2500 Green Gorilla motor burns for just over three seconds and then at seven seconds into the flight, three J420 Redline motors ignite. After that Starfire coasts to apogee and deploys the parachute. 

View High Resolution MPEG2 version     (27.9 MB)

View QuickTime version of the video     (24.1 MB)

View low res Windows Media Player version   (2.2 MB)

Vulcan was named after the Roman god of fire. It is 5.5 inches in diameter and over 8 feet long. I launched it on Sunday morning at FITS using an Aerotech M1297 motor.

Construction details about Vulcan can be found here.

Vulcan flew upwind after leaving the launch rail and then drifted right back toward the pad. It landed less then a 1/4 mile away after reaching 8,502 feet.  This was the 25^th flight of Vulcan but only the second time it has flown on an M-motor.  It was recovered with no damage.

Once again Dave Bradley helped me load Vulcan onto the launch pad and recover it.  Thanks again Dave!