Wednesday, September 28, 2016

TARC workshops and cell towers...

In terms of rocket events, September has been a busy month. A few days after the Geezer TARC launch, HARA hosted a Saturday TARC workshop at the Educator Resource Center located on the grounds of the Space and Rocket Center. The idea was to condense the information offered in HARA's hour long classes - which took place just before the monthly club meetings during TARC season -  into one day; we figured this would better enable the teams to get a good quick start into the competition. It worked out pretty nicely, and we got some nice compliments and feedback that will make next year's workshop even better.

TARC teams building the BMS School rocket at the HARA TARC workshop (Click to enlarge).
I began the workshop with an overview of TARC and this year's rules, then moved into the details of the Open Rocket design software and how to use it. Duane followed with the practical stuff - building techniques like cutting body tubes and fin slots, the double glue joint, using angle iron to mark body tubes, etc. Then each team applied some of these techniques in building the 3" School Rocket from Balsa Machining Service; it's a beefy 3" diameter, 24 mm powered bird that is perfectly suited for practicing painting and finishing techniques. Thanks to the generosity of HARA, the teams were able to take these rockets back to their schools, along with the tools and stuff they used in their construction. Mid-afternoon saw the end of the session, and I was convinced that the one day workshop was a much better approach than the classes. The kids were pretty fired up as they left, and it was clear that they had learned most of what they needed to know.

I have also been working with twelve 6th grade home schoolers at the Creative Discovery Museum in Chattanooga. Many of these kids participated in an introductory rocket workshop I gave there a few months back, and the museum decided to follow that workshop up with a month devoted to designing and building egg lofters - a "pre-TARC", if you will. The 2 hour sessions were held each Tuesday in September, and I conducted the first one via Skype. It was devoted to designing rockets using Open Rocket, with the students creating rockets capable of carrying an egg to 300 feet. The second class saw me traveling to the museum, where each of the four teams (consisting of 3 kids) built a Quest Courier egg lofter. I was in Europe on business last week, so the students took advantage of the class time to decorate the rockets, and yesterday was the much anticipated launch day.

Egg lofter designed by a team of 6th graders at the Chattanooga Creative Discovery Museum (Click to enlarge).
While I was in Europe, I realized that a frequent attendee at the Manchester launches, Keith Nyman, lived in Chattanooga and figured it might be a good idea to introduce him to the museum folks - an experienced local rocketeer is a handy resource. Fortunately, Keith is not one to pass up a rocket launch, and I was very pleased that he came out to help with the egg lofter launches; the two of us made short work of assisting the student teams in preparing their rockets for flight.

At the first workshop, the Creative Discovery Museum had obtained permission to launch on the banks of the Tennessee River in downtown Chattanooga; the proximity of the river to the north and busy streets to the south made for a less than ideal situation. For this launch, the museum approached Chattanooga High about using one of their fields for rocket flying, and the school kindly gave its permission. However, upon arrival I did not see the football field I was expecting; instead, I was greeted by a tiny baseball diamond, with a line of trees to the north, a construction site to the west, school buildings on the southeast, and a large cell tower at the southwest corner. Not good. Even though there was little wind, the available clear space was very small. Keith was very concerned about rockets landing on the roof of the school, whereas I was more worried about the trees and that menacing cell tower; it just screamed "rocket eater".

The pad was quickly set up and the launch got under way. The first Quest Courier powered off the rod on a C6-3, soaring up into the blue sky. Ejection occurred near apogee, and both parachutes deployed. I was relieved to see that the sustainer section of the rocket would land safely on the ball field, but then my worry became reality, as the egg capsule drifted straight for the cell tower, my $50 Jolly Logic Altimeter One dangling from the attach point. It landed in the middle of a small platform near the top of the cell tower, and I just knew I was being mocked by the rocket gods. There was nothing to be done, and with a sigh I turned to the students and informed them that our means of determining altitude was trapped about 100 feet above our heads. Not a good way to start.

A Quest Courier clears the pad powered by a C6-3 motor (Click to enlarge).
Keith and I adjusted the rod angle slightly, which paid dividends; both pieces of the next Courier landed in the field. The same could not be said of the last two launches - one saw a sustainer hanging out of reach on a tree branch and the other had an egg capsule drift into the forbidden territory of the construction site. This did not seem to matter much to the students, who had a great time despite the lost parts. They were thrilled to see the rockets they had built carry eggs high into the sky and return them safely to the ground - at least for the two eggs we could check. We then had a short Q&A session on the field, after which the kids went home and I returned to Huntsville. The museum was pleased, and I think they will continue with rocketry, which was the objective. Despite the loss of a few pieces, mission accomplished.

And now to find the money to replace the altimeter...

Wednesday, September 7, 2016

Showdown at high noon...

This past Saturday was the day chosen for the long awaited Geezer TARC competition launch - a rather auspicious day, being on Labor Day weekend and also the opening Saturday of the college football season. I think we will fix this day for future Geezer TARCs; it's perfect for a rocket showdown.

Duane and I were the first to show at the Harvest Horse Farm, followed in short order by Woody, Art, Nate, Chuck, and Marc. There were only three competitors - myself, Duane, and Marc - but you would have sworn there were more from the volume of the smack talk being exchanged as we set up the range. We also had spectators; Constance and some of the Hope Rising TARC folks were there, along with Marc's family and Duane's daughter and her fiancé. Thankfully some of them brought canopies, as the day was blistering hot, making us quite grateful for the shade of the tents.

Art flew the first rocket of the day, a venerable Estes Sprint that he built way back in 1970 (can you believe a rocket actually survived 46 years?). The Sprint performed well, but Art had replaced the aging shock cord with a new, modern type, thereby requiring the nose cone to separate from the rest of the rocket. Fortunately a bit of searching turned up the prodigal piece, so the vintage rocket can take a bit of rest as an intact whole.

Art Woodling's vintage Estes Sprint takes to the air as Chuck's SR-71 awaits its turn
(Click to enlarge).
Chuck then launched a remote controlled SR-71 on a D12 motor. The boost was good, but he could not pull it out of a shallow dive, which ended in a hard landing and some minor damage. Undaunted, Chuck repaired the model, made some adjustments, and flew it again. However, the SR-71 was quite insistent on heading for the ground, resulting in another crash and even worse damage. Chuck also attempted to get a composite powered Red Max off the pad, but the old motor refused to light, even with an enhanced igniter. Deciding that Fortune was not smiling on his rockets, he pulled a couple of RC planes out of his SUV and delighted those present - especially the kids - with some precision flying.

Marc prepping one of his Geezer TARC birds (Click to enlarge).
Which brings us to Geezer TARC...

Duane launched the first model, which seemed to perform well, at least in duration. The timers measured it to be 39.7 seconds, pretty close to the 41 second time mark. However, the altitude was a disappointing 525 feet, some 250 feet below the goal. Thus it was that Geezer TARC began with a miserable score of 255.

My 2017 Geezer TARC birds - the 24mm powered EggsTerminator (BT-60 to BT-70) and
the 18 mm cluster Omelet Express (BT-60 to ST-18; Click to enlarge).
I would not fare much better; my E12 powered EggsTerminator performed better than simulated, achieving an altitude of 938 feet, 163 feet above the mark. The duration, 49.8 seconds, was also on the long side due to the higher apogee. Staring at the dismal 190 score, I consoled myself with two thoughts - 1) I was ahead of Duane, and 2) the descent rate was about right. I figured the rocket would have stayed aloft for 41 seconds if it had hit 775 feet dead on.

Marc ended the first round with his "conventional" rocket. It reached 731 feet, far closer to the mark than the first two models, and was down in 29.4 seconds - about 12 seconds short on the duration. This was still good enough to put him in the lead, with a 90.5 score.

We began round 2 enlightened with the knowledge that, even with our years of TARC experience, our  scores sucked greatly, being representative of the first flights of a first year team. Very humbling.

Duane's chance for redemption and retaining his title flopped; the duration, measured at 53.5 seconds, was over 10 seconds beyond the mark, and the apogee was still 173 feet low; the rocket struggled up to 602 feet. The 215 score put the two year Geezer TARC champion in last place.

My Omelet Express flew next. Propelled by a cluster of 3 C6-5's, it soared to 763 feet, just 12 feet shy of the magic 775. However, the 12" parachute proved a bit too big for the minimum diameter egg capsule, which descended at a slow 18 feet per second. The flight duration was a long 51.7 seconds, but it was close enough to yield a score of 46.7, the best of the day. Unfortunately, the sustainer parachute was singed by the ejection charges of the the 3 motors (too little wadding) and did not open, resulting in a hard landing. Rules are rules, and so I had to disqualify myself. Nonetheless, I was pleased that my much-ridiculed black powder cluster performed better than any other rocket in the competition. And you can bet that next time I will stuff more wadding into that damn tube.

Marc ended the competition by launching his "complex" rocket, which featured onboard electronic smarts to automatically reef the parachute if the descent rate was too low. This setup was never tested, as the fly-away rail guide attached to the rocket jammed in the rail and broke free, sending the model skidding across the field. No score, a disqualification, and a badly damaged rocket. Surprisingly, the egg (and the electronics) came out of the wreckage unscathed.

The 2017 Geezer TARC champion with his daughter and trophies. Congrats Marc!
(Click to enlarge)
Thus it was, after 2 rounds, Geezer TARC had a new champion - Marc Loertscher. And in an additional bit of irony, he also received the Flying Pig Award for the worst Geezer TARC flight, as well as the winner's trophy. Congrats, Marc! You were the best and the worst! I will say Duane yielded his title very graciously; perhaps it was because he was still scratching his head over why his rockets failed to make altitude.

Duane launches his "altimeter test vehicle" (Click to enlarge).
Ever the engineer, Duane flew his "altimeter test vehicle" on an F motor; designed to check altimeter consistency, it was loaded with 6 altimeters from various manufacturers, which made an awful din with their constant chirping. Next was his upscale Cherokee-D, which was borne aloft on the flames of 3 Estes E9-6 motors. This was Duane's first cluster, and I was pleased to see it perform flawlessly; obviously hanging around me has rubbed off in a positive way.

Duane's clustered upscale Cherokee-D streaks skyward on 3 E9 motors (Click to enlarge).
It was 3 PM, and unbearably hot. We declared the Geezer TARC launch over and headed back to our air conditioned homes and college football on the TV. Hopefully there will be better scores next year!

The embarrassing scores of this year's Geezer TARC (Click to enlarge... On second thought, don't).