Sunday, June 6, 2010

Plaster City @ 108˚F... but it's a dry heat!

Yesterday was the last Plaster City launch before the summer heat break. However heat arrived early as it was 80˚F at 8AM and 108˚F when I left at about 3:30PM!!
My first flight of the day was the Viciously Mean Machine 0.75 with a CTI J1520 Vmax motor (static firing video). I prepped everything and got it out to the pad only to find that the 250G Parrot 2 altimeter would not arm. I pulled it and took it back to my prep area to find that it wouldn't even power on. I swapped 9V batteries but still now power up. Then I hooked the altimeter up to my computer to find that 4 of 5 memory banks held data. I knew that I'd purged all flights the night before so this was confusing. I then figured out that the Parrot 2 stores a bank of data every time it's powered on and I must have cycled power a few times while setting up. After purging those four data banks the altimeter again operated as expected. This still doesn't explain why it wouldn't power up the final time as one bank was free. Whatevs. I reassembled everything and again set the rocket on the pad for flight.
I knew this would be my fastest flight ever so I had really gone to great lengths to ensure the whole setup was reinforced, taped, and positioned for a neck-snapping liftoff. When I pushed the button VMM 'sploded off the pad, burned out quickly, then literally disappeared for a few seconds. Here are 3 of 5 frames at 30 fps from my Flip MinoHD video cam (video below):
(I estimate that flame to be ~4.5' long)

Only when we saw the tracking smoke did we understand the rapid progress of the flight to between 6000-7000 ft. I watched as the 17 seconds of smoke burned and the rocket passed apogee without an ejection event. Unfortunately as the smoke burned out we lost site of anything. I had a radio beacon in the rocket so I thought I was fine until I turned on the tracker and got no beeping even with long range and high gain settings. Bummer. It's very likely that something connected to the altimeter had dislodged under the tremendous acceleration and the rocket had come in ballistic destroying my $500 investment (excluding the price of the reload by the way). Sad. I made three attempts to find the crash site sweeping over quite a large area including KO's help on the third, highest temperature slog (click for larger version):
I had planned to fly a CTI L730 Classic in my Vertical Assault but was pretty daunted after that first failure. Instead I flew one of the new Pro29 G250 Vmax motors in my Dark Star Lite and it was shockingly fast! My third and final flight for the day was on a Pro29 I204 Imax motor (6G) where I'd planned to set up a new camera angle at 8 fps. The dude who launched before me didn't check to ensure that only his pad was armed and launched our inadvertent drag race before I could set my camera up. He was super cool about it and offered to buy a replacement motor but his offer sufficed and I thankfully declined as it wasn't a big deal. I'm hoping I've shaken out all the back luck prior to LDRS next weekend because I need successes there!!

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