Sunday, December 30, 2012

Plaster City June 2012 launch report

This post might be out of date but at least it's up faster than the time it takes stupid Cobalt-57 to decay by half so there!

We in San Diego's branch of Tripoli elect to shut down from July to September of each year and with good reason: this June launch exceeded 108F by the time I left and I was feeling it!  My heat tolerance is gradually decreasing so, note to self, I'll plan to recover via driving at the June 2013 launch.

I think I flew only my DarkStar Exreme on a CTI 3683L851 White reload that day (Pro75, 3G).  This reliable rocket once again tallied an excellent flight and recovery (sorry the song cuts off, Alessandro Diga, but I'm likely not gonna change it unless you ask :)

That motor kicks ass so go buy/fly one.  I'm sorta terrible at verifying the numerous camera settings required to dial in my signature photo recipe when switching situations (studio, outdoor, rocketry, etc).  This time everything was correct except that I'd been shooting in JPEG-only mode (no RAW) during the last session and forgot to switch to RAW.  JPEG is so overprocessed and otherwise dead from an editing perspective that I almost never shoot in that mode unless photo delivery time is paramount or if editing in RAW is not an option in the time allotted.  The delta between JPEG and RAW has never been more apparent to me and this is the best I could do with this comparatively lifeless image format:
On this blog preview it's not nearly as apparent to me as when trying to tweak in Adobe Lightroom so... Hey isn't that another great liftoff image, folks?!
     Now onto Mark Clauson's incredible help that day... Again I normally prefer to walk as I practically grew up in the desert.  My GPS receiver indicated that the touchdown was 1.2 miles due east so I grabbed my water bottle and started walking in that direction.  About 0.6 miles out I was really feeling the heat and my ass was dragging when I realized that I wasn't half way there but 1/4 the way there including the walk back.  Then I see a black truck barging out in the direction of my rocket and I'm instantly annoyed as non-flyers have driven toward my distant rockets before (and even stole one in the Bay Area!).  I started walking a bit faster when I noticed my GPS position was quickly moving toward me and... there was Mark in his truck!  He had been leaving when he saw a rocket landing the east and thought it might have been mine.  As he didn't have my cell phone number he most cleverly looked up my nominal GPS frequency on the club web site, dialed it into his radio, and drove right up to my rocket.  Mark and his dad, Craig, are truly formidable rocket hunters and I can't thank them enough for all the times they've saved me a substantial walk.  In any event THANK YOU BOTH!!
     In retrospect I've had only 2-3 unmitigated successes with my now older Beeline GPS transmitter (success = precise recovery + unambiguous flight path data).  This time I received what seemed to be accurate heading and distance data but no live GPS altitude data.  I value this system not only because of it's potential to guide one precisely to one's rocket but also because it logs data that can be plotted later in Google Earth. Well the last few flights have yielded garbage in the human-readable portion of the XML data and, initially, that was my concern with this L851 flight data.  However, when I plotted it in Google Earth, it produces yet another useless (?) result as I don't recall flying this combination twice and I'm going to start calling these GP[MESS] plots:

When the thing worked I noted excellent agreement between the GPS and barometric altitudes but now I think this unit is all but dead to me.  [Note: I've since purchased a new Beeline GPS thinking I'd done something wrong in the past but, as you'll read in later posts, the data from the first flight on the new unit was again useless.  Luckily three of us experienced the same issue so we suspect GPS satellite issues that day]  In any event the average of the ARTS2 and Raven2 barometric altitudes was a respectable 10,488' and the ARTS2 software says the L851 behaved more like an L964 with a 3.98 second burn time.  Here's the output from the altimeters if you're interested:

Raven2 - Graph, Tabular
ARTS2 - Graph, Tabular, Motor Performance, Coefficient of Drag

Thanks for your patience and tenacity and may you break a personal record or two in 2013!

Thursday, December 20, 2012

No I haven't forgotten my blog...

I'm just way behind in several areas of life.  I'm about to get some time off so I hope to catch up a bit.

Happy holidays, all, and keep the hydrogen chloride emissions out of the eyes in the new year!