Plaster City - March, too-zeero-won-thrie launch report

Another redemptive, windless day in the Imperial Desert...  I think my head might 'splode with gratitude after years of prevalent, forced, mass convection.
     From last month I left Em-Sem-Fity mostly set up for the AT K458 White Lightnin' 'load but, despite that tremendous head start, I still managed to fly only that rocket and shoot a pitiful rooker-full of photos.  I'm gonna be brief today and rely on photos as proxy for 1000 words each.
     I vowed to use more thermite this flying season and I'm off to a fine start.  Having metered 3g of stoichiometrically-balanced CuO/Mg thermite, added one e-match, and asked Rick Frelke to push the button I finally saw fairly rapid ignition of a 98mm, 1G motor about one second after the pop.  Enjoy two ignition frames 1/10th of a second apart:

And a graceful liftoff:

Once again, due to low wind, I elected to pop the main at apogee. I had a perfect heading at landing and all looked well until I had walked well past the visually estimated landing spot.  Oh and... yes I did use a Com-Spec tracker but I was SO confident that I knew the landing spot that I left the receiver at my table.  Jenius.  Lesson: always take all that [light] equipment no matter what.  As I was walking back to grab that receiver I saw Darrel looking for his own 20k President's Challenge rocket.  He called to tell me he'd found mine on the north bank of the first wash heading north.  For some inexplicable reason I had meandered WAY east on my outbound journey and therefore missed it.
     Prior to flight I checked the static margin and it seemed way low so I added a 1lb weight to the nosecone base.  This increased the liftoff weight to 19lb and that resulted in a lower altitude than last month's K1999.  The K458 yielded a 6,695' barometric average (ARTS2=7,079', Raven2=6,310') with a pretty big delta between the two altimeters.  Enter... data:

ARTS2: tabular, graph, motor performance (2238K374), coefficient of drag
Raven2: tabular, graph

Oh and, in leveraging last month's K1999 ARTS2 file, I realized that I somehow had entered the liftoff weight in kg rather than lbs.  The above motor performance reflects accurate liftoff lubs and appears reasonable. I'll also correct the K1999 data below.

Plaster City launch report for Feb/2013

Reporting the day after the launch?  Unheard of yet so very true!  Here are all my select photos from yesterday.  Oh and it's [not at all] hilarious now but I managed to forget my motor casings, bottled water, and K1999 liner yesterday!  Packing FAIL. Rectification required.
     Despite the weather predictions... we again enjoyed windless flying conditions in the Imperial Desert with clouds materializing only later in the day.  I seek to fly as many motors of interest in this life and yesterday ticked another off my bucket list with a CTI 614I100 Red Thunder long-burn in the reliable Polecat Aerospace 4" V2.  I forewent video so here's the record of photons sequestered:


You'll note that the liner started to burn through but my new Pro54 3G casing remained unscathed. Here's the Altimeter Two data:

Attribute	Value
Peak Altitude (baro)	4,491'
Peak Velocity	301 MPH
Motor Burn Time	4.0s (2s short!)
Peak Acceleration	16.5 gees
Average Acceleration	3.5 gees
Coast Time	14.8s (long by 3s)
Apogee-to-Eject	-11.2 s (?)
Peak Altitude (accel)	2,642' (?)
Descent rate	7 MPH
Flight Duration	262.6s

Created with the HTML Table Generator

Next up was my scratch-built Em-Sem-Fity on an AT 2540K1999 Warp9 reload.  Jack kindly loaned a casing to me yet there's still something missing... oh yeah it's the friggin' phenolic liner resting comfortably in my downstairs closet!  I remedied this buy buying an AT K458 White Lightning reload, used that liner yesterday, and will use the K1999 liner next time.  Here I'm about to shot-put .. I mean load up the "coffee can" motor:

The cloud cover had rolled in by the time I loaded up and then I had a slew of igniter problems but it was all worth it with this stunning, mach diamond-laden ascent!:

There was zero wind so I popped a 9' main at apogee to reduce my prep time and we landed about 1/4 mile west:

I think I figured out some of the igniter problems:
1) The first CTI dipped e-match partially burned and failed to ignite the motor.
2) Then I switched to one of my personally dipped igniters.  Despite their high historic reliability this, too, failed.  I'm guessing the pyrogen wires were shorted internally so it showed continuity but never burned.  We also had a strange problem where I showed continuity at the pad box but not at the launcher box.
3) In the end I hooked up my Rockontroller and, with Jack's help, selected a third igniter and got that AP burnin'.
Thanks to Dave and Jack for working through those issues over a half hour with me.  And thanks again to Jack for the casing loaner! RockSim 9 predicted 7,379 and I thought the program was high :). The ARTS2 (7,056') and the Raven2 (7,093') averaged 7,075' so the simulation hadn't been as baked as I suspected. Here are the details:

Raven2: graph, tabular
ARTS2: graph, tabular, motor performance (corrected liftoff weight yields 2562L1601), CD (corrected as well)

The peak acceleration was only about 25 gees (nowhere near the 50g accelerometer max) so I'm really not sure what's up with the motor performance data [Now I am.  The liftoff weight stuck in kg rather than lbs. so I've corrected that above].

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:

Attribute	Value
Peak Altitude (baro)	5,370'
Peak Velocity	649 MPH
Motor Burn Time	1.6s
Peak Acceleration	22.9 gees
Average Acceleration	18.3 gees
Coast Time	12.3s
Apogee-to-Eject	-0.2 s
Peak Altitude (accel)	5,217'
Flight Duration	226.6s

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!

Plaster City December 2012 launch report

I'm clearly on a blog roll now...

My goal for December was fun and easy flying so I packed sparsely planning for no dual deploy, no onboard vid, and no GPS headaches.  I sought leisure via simple motor ejection and perhaps a Jolly Logic Altimeter One thrown in for good [barometric] measure.
     Jack had the new CTI Pro38 654J316 Pink reload in stock so I snapped one up and threw it into my trusty Bullet for its trillionth flight (click to enlarge):

The neck-snapping ascent rocked and I'm a bigger than of pink than ever.  Real men fly pink.  The Jolly Logic reported 4,075' and there was much rejoicing.
     I also had this CTI Pro54 1990K490 Green^3 [figuratively] burning a hole in my closet and it seemed perfect for my 5.5" Polecat Aerospace Jayhawk that I hadn't flown for some time.  The pressure-up was a bit slow but I never get tired of that stunning, barium-free green flame (click to enlarge)

The uppage was way cool until 'round about Max Q when it looked as if a canard fin had ripped off.   Hmmm I'd built this thing quite robustly but it's hard to reinforce those big, potentially floppy wings. In any event the parachute appeared to eject right at apogee but wasn't fully inflating.  Despite taking my own advice and repacking my 'chute immediately before flight, unfortunately, the 12' diameter behemoth fluttered ever groundward without ever fully inflating. I very close to touchdown and could see all the wings/canards had survived the flight. The as the Jayhawk impacted the ground one corner of one canard cracked on impact.  So yet another stooped fouled 'chute had damaged yet another prized rocket:

The Jolly Logic altimeter reported 4,711' but I wasn't sure if I could fix that fin.  Jack thought he might have a spare at home but I decided that a) I don't really want to fly rockets that flap about at Max Q and b) I don't maintain a rocket museum at my house for show-rockets.  In the end I salvaged what I could and dumped this orange rocket in the trash.  Oh and about that time I noticed that a hole had been poked in the nosecone as well so double-hmph.

Plaster Blaster 2012 launch report

PB2012 was a great launch for me featuring two days of amazing weather, no camping required as I've discovered El Centro hotels,  and I was very pleased with the fourth flight of my scratch-built Em-Sem-Fity minimum diameter 98mm rocket.
     Frank Hermes, Mark Clauson, and I entered this year's fourth and likely final M-Moonburner drag race.  The new BLM requirement that drag race flyers must ensure a recovery radius of 25% of the expected altitude from the nearest public features like roads and high-power wires was kind of a bummer.  This pushed our launch pads to the north edge of our 'bowl' and, earlier, we had set them up in patches of dirt distant from flammable brush.  After we'd prepped it was kind of Mark and Craig Clauson to drive all of us out to those launch pads where we set up quite quickly.
     I wasn't able to take any liftoff photos but can at least move the onboard video to this post (same as you might have seen earlier but why not watch it again? :)

     Frank really wanted to win again this year and I was with him the night before when he purchased plastic wrap and cellophane tape to seal up his 10g thermite bundle for ignition.  Jack Garibaldi offered the use of his super high current launcher and it did its job well. Frank's M750 of course pressured up instantly, followed by Mark's trusty M650 setup, and then my lagging ass standard igniter pressured up the M750 for third place.  All three rockets flew somewhat neatly apart from each other atop those fun long-burn M motors.  Note to self: I really want to start using more thermite in 2013.

     All three of used Beeline GPS units for tracking this time. Mark was having issues with his proprietary GPS setup so Frank loaned a spare Beeline to him.  I was using my brand new transmitter of the latest design and I was confident that it should work.  As always I threw in a Comm-Spec tracker as a reliable backup.  Strangely we all had intermittent issues with maintaining satellite lock on the ground. Likely causes might have included general satellite interference or possibly military jamming although that remains speculation on our part.
     After liftoff none of us received any GPS updates but my Comm-Spec receiver continuously produced a healthy blip.  Its signal conveniently increases in strength/volume at apogee because the transmitter moves outside the carbon fiber body tube.  So, even though I can no longer see the rocket, I have an audible indication of apogee separation.  Interestingly, and highly abnormally, my ~20,000' flight landed inside the bowl!!  I was really psyched on this and we could see the main pop at 800' as expected.  My elation quickly subsided, however, as my buddies Frank and Mark still lacked any trackable signal as I was gathering up my bundle.  We searched for some time but later learned that Frank's rocket had come in ballistic leaving little of salvageable value.  Mark was never able to find his rocket and it remains missing to this day.  Sorry fellas but it's happened to all of us.  :(

     Back to my new Beeline GPS... the downloaded .kml file produced a beautiful firework-like burst of points all very near the ground:

WTF??  While no altitude data point in the file gets anywhere near 20k I can say that none of data rows seems askew as with my older unit (no negative latitudes for instance).  From this January's launch I'll foreshadow that the GPS unit is ignoring the 'convert meters to feet' flag in the programming software so the peak value in this data set would seem to be 178m or 583'.  I think this looks close to what I'm seeing in the plot above.  I'll attribute this data failure to GPS satellite or scrambling issues as the unit now appears to be working correctly so... YAY!!  Finally.
     As for altimeter data the Raven2 reports 19,465' AGL and the ARTS2 looks good at 19,561AGL (0.4% delta).  It appears that the ARTS2 motor performance data is whacked at 6964M1004 with a 6.98 second burn time.  From the onboard video the burn time is roughly 14.3 seconds so let's assume the ARTS2's motor performance estimate is null and void.  Here's the data for the numerically retentive:

Raven2: Graph, Tabular
ARTS2: Graph, Tabular, Motor Performance (WRONG), Coefficient of Drag (questionable)

Frank was understandably bummed at his loss and was talking of retiring from rocketry before leaving the launch.  Since then he says he's exited his slump and wants to build a nifty clustered/staged rocket using his Tilt-O-Meter2 at some point soon.  I'm glad he's back on the horse and hope that Mark's recovering from his loss as well.  I'm not sure what we'll do at this year's Plaster Blaster but I'd like to avoid the BLM constraint on launch distance so we'll see.
     We flew a mini drag race on Sunday limited to G motors.  I chose the CTI 110G250 and it was sorta fast.  Victory at last!!

BALLS 21 does not equal gonads now legally authorized to consume ethanol...

...it offers far more to the cutting-edge rocketry community.  Let's start with the video fragments of my first N-motor flight (720p/full-screen always work best):

I'm quite happy with the video I was able to salvage but I'll leap to the executive summary:

What worked:

• A mostly cop-free 11-hour drive from Oceanside, CA to Black Rock, NV and back.
• The brilliant foresight and planning of my fellow San Diego fliers.  We had an amazing compound nearly dead-center on the range.  Thanks, compadres!
• A beautiful CTI 14272N1975 Green^3 reload (thanks to Kris' friend Molly for shooting):

• Perfect flying conditions on the days I attended.
• Unparalleled and proactive mutual respect from all fliers in attendance.  I was somewhat awed by the inverse attitude/magnitude relationship!  This is a very cool community.
• Mark and Craig Clauson's incredible rocket hunting ability! Thank you both once again.
• Frank Hermes' amazing 2-stage flight featuring the Tilt-O-Meter 2.
• Everything else except...

What didn't:

• Not repacking my main 'chute!!!!!!!!!!  For the first time EVER by the way.  This seemingly minor error on my part converted my 'simple, fun first N motor flight' into many, many small but costly repairs and replacements.  Repack your recovery system every time por favor.
• Camping.  I suck at it and I'm at peace with that.  The first night was unbelievably cold and the second night was warmer yet provided just enough wind and flappy tent top that I attained approximately zero REM sleep.
• My older Beeline GPS.  I was locked on the ground but never received any position or altitude data and my Google Earth plot was a complete GP[mes]S once again.  Yes four data points points can form a trapezoid but... ummm... ?:
  
• Friggin' tattle tale Nevada drivers and innumerable 65-55-45-35-25 zones on state highways 50 and 447.  Can they be serious?  My jaw remains agape that some kindergarten-level utility truck driver in Fernley radioed in to the police that he thought I was following too closely.  Well fuck that guy 'cause he apparently needs to create some genuine drama in his life as I pay painful amounts of attention behind the wheel.  Bonus: the cop was the coolest I've met in my life.  He checked my docs, let me go without even a warning, and provided driving advice to Black Rock.  Now that's what I'm talkin' 'bout!!
• Sadness that I just typed way more negative words than positive because...  

This events rocks and experienced fliers simply need to ditch their families for a couple of days and participate at least once in their lives.
     So the up part was amazing, the down part was invisible, both GPS and Comm-Spec tracking failed, and the formidable Mark & Craig Clauson returned my rocket.  Upon first inspection I was very happy but, over the coming days, I slowly realized the damage that a fouled main can do.  I won't belabor it but I suspect my ARTS2 was concussed so I'll estimate my final peak barometric altitude at the Raven 2's ~17,963'.  For my data-nerd-bretheren here are the various outputs:

ARTS2 + grain of NaCl: graph, tabular, motor performance, coefficient of drag
Raven 2: graph, tabular

I might append more later but, in summary, repack that main, drive as slowly as humanly possible in NV, and be sure to use your CB to narc on my CaliForNyAy drivin' ways.  Thanks for reading and exceed all expectations of yourself.

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!

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!

=G=

BALLS 21 brief update

Hi, all.

Bottom line: if one has an opportunity to participate in a BALLS launch...  do it!

Never in my life have I met a more amazingly skilled group of rocketeers who also offered mutual respect right up front.  The atmosphere seemed calm, comfortable, and humble.  Thanks to everyone I met at the launch and especially to my friends from the San Diego club for harboring my newbie self. Oh and props to Mark and Craig Clauson who may now rightfully usurp the name "rocket hunter" as they've thoroughly mastered the subject.  Honorary Ph.D to you two!

More to come...

I like 25,000 hits.

Simply declaring.