Sunday, January 27, 2013

Plaster City Jan. 2013 Launch Report

Executive summary for San Diego's first launch of 2013:
  • Brilliant weather!
  • Unparalleled assistance!
  • Great launch success!
  • Liftoff photos and onboard video?  Not so much.
First off I'd like to thank Darrel, KO, Jason, and Jonathan for all their help that day.  We've been really lucky at Plaster City in recent months and the myriad wind deities seem appeased; it really is amazing how they play together despite disparate origins.
     I actually painted a fiberglass rocket!  Rattle-can painting has simply sucked ever since really robust surfactants have been phased out.  I'm all for environmental protection but will challenge the paint industry to synthesize equivalent substitutes that actually work well!  I think I found a reasonably good substitute admittedly at a greater cost: Krylon Fusion.  It's designed to adhere to low surface energy plastics seems to work similarly to older paints as I recall.  Here's my DarkStar Lite all prepped and pretty on a CTI 382I243 White:

The turbo ascent and the long telephoto lens conspired to prevent a liftoff shot but KO did catch my aft rail guide flinging into the air and that's cool:

I had also purchased a Jolly Logic Altimeter Two and this was its first flight.  While there's no data download/graphing capability I must opine that the list of flight attributes impresses:

Peak Altitude (baro)5,370'
Peak Velocity649 MPH
Motor Burn Time1.6s
Peak Acceleration22.9 gees
Average Acceleration18.3 gees
Coast Time12.3s
Apogee-to-Eject-0.2 s
Peak Altitude (accel)5,217'
Flight Duration226.6s
Created with the HTML Table Generator

Note!: One needs to clear the data after each flight as these altimeters do not auto-reset.  I learned this lesson later that day...
     My second flight took a super long time to prep because, well, I'm me.  I had finally finished building what I call the DarkStar Extreme 'Heavy Duty' which is a misnomer because it's actually of nominal strength.  You may recall that I was sent the wrong fins on my original DarkStar so this second booster build gets me back into the nominally heavy duty range.  Darrel not only help me set up the flight but also lugged the beast out there on his own and thanks again!:

I've been wanting to fly the CTI 6162M1675 Pink reload for over a year now but my previous "lite duty" booster seemed on the edge of strength with the CTI 4828L1410 Skidmark flown last year.  The night before I also had the idea to launch another fast rocket with onboard video just as the M1675 was pressuring up to hopefully produce some amazing ascent video from two perspectives.  I chose my trusty Bullet on a CTI 419I800 Vmax reload for the chase-cam video.
     The M1675 pressured perfectly, the I800 ignited instantly and lead by the amount I'd imagined, and both flew and recovered perfectly!  Here's a shot of the M1675 pressuring-up and that puff on the right shows the I800 ignition timing:

Here's a closer crop of the beautiful, nebula-like, red/purple startup fireball:

Unfortunately the M1675 onboard video was corrupt after downloading.  I'm trying to salvage it and will post any recovered action in the future.  The I800 video was completely absent!  I know I started the camera correctly but there wasn't even a corrupt fragment to try to recover.  And, as I'd mentioned, I failed to reset the Altimeter Two and have no I800 data.  Wow.  Now back to good news: the Beeline GPS worked flawlessly this time both for recovery and data plotting! (looking West, click for 2x larger version)

I had perfect satellite lock the whole time and saw a peak altitude of 13,077' on the Yaesu radio display.  The peak altitude in the human-readable portion of the .kml file is 4,317m or 14,160'.  The average of the ARTS2 (13,621') and Raven3 (13,898') is 13,760' so that's only 2.8% lower than the GPS peak.  For the data retentive (corrected links thanks to Darrel):

Raven3 (250G model): graph, tabular
ARTS2: graph, tabular, motor performance (5727M1786), coefficient of drag

Based on this success I've queued up an 6800M3700 White Thunder soon but think I'll fly a 'mellow' 7388M2045 Blue Streak in February first.  And with that entry I'm caught up for the first time in a year.  Cheers to continued success and viable onboard video!

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