Sunday, June 15, 2008

Flight day... Yay then boo!

Alright so first off I want to thank Kurg Gugisberg and "Dok" Hanson for acting as my Technical Advisory Panel members.  I also want to thank my buddy Doug for helping me drag this beast around the lakebed in the heat all day.  His son Brandon shot video of the flight and my friend Kristine shot photos and toted my tripod/1Ds mark III/300mm f/2.8 IS lens around in the sun for hours.  I'm grateful to all of you and this certification attempt wouldn't have been possible without you!
       I rented a minivan on Friday and had it loaded up by about 10PM that night.  Doug, Brandon, and I headed out at 5:50AM the next morning, encountered no traffic, and touched down at Lucerne Valley dry lake bed at 8:25AM.  There was NO wind which is a small miracle these days.
       I immediately headed over to Jack Garibaldi's "What's Up Hobbies" trailer to borrow the 75 mm/5120 N•s casing for my cert flight.  Someone else had beat me to it so I dropped back and prepped everything but the motor.  The electronics wiring and payload assembly came together without a hitch.  I then took the partially assembled rocket over to "Dok" to check the build and authorize the flight.  He looked through my documentation and asked "What's the thrust in pounds of the motor you're flying?"  I froze up a bit because I knew that answer but it wouldn't come to me.  I offered "1297 newtons divided by 4.45 N/pound-force... now if I only had a calculator."  Dok was fine with that answer and after an inspection authorized me to fly.  I then needed the same checkout by Kurt but, sadly, he'd just crashed a very beautiful/complex project and was just heading out to pick up the debris.  I felt so bad for him!  It's so painful to work that long on something, one little thing goes wrong, and the whole thing goes down.
     Now I'm waiting for someone to announce a level 3 certification attempt on an M1297 because this will tell me who has the casing I need.  At about 11AM I hear that Jim Hawk is flying his Polecat Aerospace Army Hawk rocket on an M1297 for a level 3 cert attempt.  Bingo. His flight appeared beautiful to me.  I wandered over to find Jim and let him know that there was no rush but I needed to borrow the casing whenever it was cleaned.  At this point I'm starting to feel a breeze and I begin panicking because the wind almost never subsides once it starts in the desert. Unfortunately Jim suffered a failure known as a 'zipper' where the shock cord tears through the body tube due to the extreme ejection forces involved.  One very important element of any certification attempt is that the rocket be recovered ready to fly without repair so Jim had failed to certify.  After about 20 mins Jim handed the casing over to me and I ran back to prep the motor.
     It's amazing that this huge motor is much easier to assemble than than a hobby store motor! It's a very elegant design and it was built and loaded into the rocket in no time.  The final weight was ~47 pounds with the motor.  Doug was concerned that the whole thing was too heavy and I must admit I was also a bit concerned that all my simulation work was inaccurate.  In the end I trusted Rocksim and we carried the rocket over to Kurt for examination.  He said that the 1/2" tubular nylon included with the kit was small for a level 3 attempt and offered his 1/2" kevlar cord to be attached in parallel as a reinforcement.  After this he signed my paperwork and we proceeded from the range safety officer to the launch control officer and out to the pad.
       Doug and I loaded up the rocket on the launch rail in a horizontal position.  After tilting the rocket to vertical I found that my original plan to pull the payload section off and arm the electronics would not work without a stool to increase my height.  We then moved the rocket horizontal again, armed the electronics, and re-raised the rail.  I installed the igniter and we were all set.
       After some additional waiting the launch control officer announced my flight at about 1PM. The wind had oscillated between 0 and 8-10 mph so I'm stressing at this point.  Right before launch the wind calmed down and the flight was beautiful!:
The delay seemed a bit long to me but everything looked fine as the parachute ejected and inflated.  I was elated!  I ran about 1/2 mile out to the rocket now on the ground only to discover that I'd zippered both tubes!! Dammit!   How had this happened?  I'd never zippered a single rocket in 32 year of flying rockets.  Did it HAVE to happen now?!  Apparently so.  It's interesting to note that the altimeter was not beeping out the altitude as it should have been.  Doug and I carried the damaged rocket back and I had to tell Kurt that I'd failed.  
     I'm convinced that I'd done everything I could to fly successfully so I'll need to do some thinking to determine root cause.  I was planning to buy another kit to try again but I had an epiphany while standing in line: I can rebuilt it better than it was. Better. Stronger. Faster.  As such I purchased two 48" lengths of 7.5" diameter phenolic tubing and three 12" long coupler tubes.  I'm thinking the rebuild should be comparatively quick and should also allow me to put the video camera back in.  Yay!  Wish me another round of luck for October or November of this year, por favor.

No comments: