It's a good thing that the weather was wonderful this past Saturday, because Duane and I spent 7 hours - from 9 AM to 4 PM - at Pegasus Field working with the local TARC teams. Eight made an appearance; 3 from Liberty Middle (2 8th grade teams and 1 group of 7th graders), 2 from Buckhorn (Team Gold and Team Blue), the Falcon Rocketeers and Jurassic TARC from Pope John Paul II, and the Hope Rising team from Hope Christian Academy. As I said, the weather was perfect - bright and sunny, with a light to moderate wind out of the east. Great weather means many TARC flights, and since Duane and I were the only two TARC mentors on the field, we were kept quite busy, especially as the day wore on. Fortunately, the teams pretty much knew what they had to do, so our role was that of scorekeeper; any advice would have been too little, too late.
Getting ready to fly some TARC rockets (Click to enlarge)!
There were quite a few practice flights, but what counts are the qualification attempts. Nineteen of these were made - 9 by the Liberty teams, 6 by Buckhorn, 3 by the Falcon Rocketeers, and the final qual flight of the Hope Rising team. Jurassic TARC didn't make a qualification attempt, as mishaps in early practice took out both their rockets; hopefully, they can rebuild and get them in before the April 4 deadline. Buckhorn Team Blue had the best score of the day, an 11.56; in an ironic twist, they also had the only disqualification (cracked egg) of the 19 certification flights. By the time we left at 4 PM, seven TARC teams had finished all three allowed qualification attempts, which is a very good tally for a single day. I felt a great deal of pride in these teams - they worked hard, and pushed through to the end. I expect the Huntsville area to have its best year ever in terms of number of qualifications turned into TARC HQ.
Buckhorn Team Blue adjusts the angle of their rail
(Click to enlarge).
Buckhorn Team Gold connects the igniter (Click to
enlarge).
Liberty Team 1's Jupiter VIII (Click to enlarge).
Liberty Team 2's "Atomic Bomb", now a Frankenstein
with a "BS1" designation on one side (Click to enlarge).
A very active field (Click to enlarge)!
There were also the usual modroc flights that are a part of every foray to Pegasus. Despite being busy, I managed to fly two of the four rockets I had stashed in Duane's SUV. My Estes Snitch took to the air on the first flight of the day, powered by a C6-0. Around 12:30, I managed to launch my Estes R.T.F. (Ready To Fly) Nova, augmented by a Estes BT-55 booster stage. The D12-0/B6-4 motor combination almost took the rocket out of sight, and I was very thankful that the winds were light enough to permit a landing near the western edge of the field. Duane launched his black and white Estes Leviathan on an F motor; it got some good air, and the parachute was deployed right at 300 feet by a Jolly Logic Chute Release. Those little gizmos are a must have, especially if you are going to fly mid power in small fields.
My Nova awaits launch (Click to enlarge).
Duane's Leviathan clears the rail (Click to enlarge).
Marc and family also paid us a visit, showing up just a little after nine. The newly-repaired Red Grasshopper made a couple of flights; his Orbital Transport also performed well, if you ignore the fact that the glider kinda fluttered in. The triming of that little beastie is notoriously difficult; I have only seen three proper Orbital Transport glider flights in all my years as a rocketeer. Before the Orbital Transport flight, Marc flew another, more conventional boost glider, which actually glided; the day would also see the launch of a small, bright orange scratch build ("The Razor") on a 13 mm motor.
Marc's boost glider takes to the air (Click to enlarge).
The Red Grasshopper returns after a successful mission
(Click to enlarge).
The last team finished around 3:45 PM, and an exhausted me was back in my apartment by 4. After stowing my stuff, I treated myself to Moe's BBQ before taking a short nap. This is a proper way for an old rocketeer to cap off a long launch day.
Congrats to all the TARC teams who finished on Saturday!
Much has been going on lately - this year's TARC season is coming to a close, and there have been lots of flights made as the deadline nears. Unfortunately, I haven't been up for blogging - I was hit by a bout of bronchitis, which took me out for a few days, and recovery has been slow. However, the blog must not be neglected, so today's post is kind of a picture log of some flights made back on March 6. The birds that flew on that day were all Centuri clones, hence the title of this post.
My RX-7 clone on the pad, loaded with a B6-6 and
the Altus Metrum Micropeak altimeter (Click to
enlarge).
Liftoff of the RX-7 (Click to enlarge).
The GoPro camera view of the RX-7 leaving the rod. Note the flying igniter plug at right (Click to enlarge).
Proof that staging does not always yield higher altitudes for the equivalent impulse. Compare this plot from December 5 in which the RX-7 flew in its two stage configuration (A8-0/A8-5) to the one below it, which is the March 6 flight of the RX-7 on a single B6-6. The RX-7 went over 150 feet higher with the B6-6!
Next up was my Long Tom two stager, powered by a B6-0/B6-4 motor combination:
The motor in the Long Tom's lower stage ignites
(Click to enlarge).
The Long Tom descends to Earth under an orange rip
stop nylon parachute (Click to enlarge).
The Long Tom streaks up the rod (Click to enlarge).
The Long Tom was followed by my Screaming Eagle clone, propelled by a B6-4:
The Screaming Eagle on the pad (Click to enlarge).
And in motion (Click to enlarge).
My last two flights involved clones of a couple of Centuri science fiction rockets. First was the Vector V, first released way back in 1972. Back then, I put a several into Oz by stuffing C6-7's into them; age has moderated me a bit, so this flight was on an A8-3:
The Vector V on the pad (Click to enlarge).
Smoke billows out from the bottom just before liftoff
(Click to enlarge).
Finally, my Taurus clone, on a B6-4:
My Taurus looking pretty on the pad (Click to enlarge).
The Taurus clears the rod (Click to enlarge).
The Taurus heading up into the blue sky (Click to enlarge).
Another nice day, which means more TARC practice and flying at Pegasus field. Today was also the first HARA launch of the year up at the Manchester sod farm, but Duane and I opted to stay in town so we could support the teams at Pegasus. March is crunch month for TARC, and our teams need all the practice and help they can get as we come down to the early April deadline. We can catch next month's launch up at Manchester.
Morgan gets the ICW ready for its first flight (Click to enlarge).
Hooking up the launch controller (Click to enlarge).
ICW arcs into the wind (Click to enlarge).
Four TARC teams were on the field today - three from Liberty Middle, and a first year team from Hope Christian. Liberty had their first bird in the air by 10 AM; four more flights would follow. Unfortunately, they were plagued by the same problems they faced last Saturday - kicked motors and peak altitudes 50-100 feet shy of the goal. They also had some parachute issues, and a couple of hard landings put an end to their practice just before noon. Hope Christian brought one rocket to the field - a silver nosed model called "ICW" (In Case of Werewolves). ICW's first flight followed the day's trend - the shock cord pulled free of the bulkhead and the payload section landed hard, resulting in an eggs-emplary mess. But the Hope team exhibited the attitude of their name, and had the rocket ready to fly again in an hour, thanks to good field repair work. ICW put in two other mishap-free flights, though both were short of the altitude mark. However, it was a pretty good performance for the first practice of a first year team; believe me, I have seen far worse.
Marc hooks up his Alien Invader (Click to enlarge).
Marc's Orbital Transport lifts off on a B6-4 (Click to
enlarge).
Marc was also at Pegasus, accompanied by the family. His Apogee Diamondback led off with an excellent flight on a C motor, recovered by a huge purple streamer. This was followed by an Estes Alien Invader on a B6-4, and the Semroc Orbital Transport that was damaged last week before it could fly. The Orbital Transport flight went without a hitch, with the sustainer descending on a nice bright orange parachute and the glider fluttering to the ground. Marc's final launch was that of the Diamondback on a B6-2, which pushed it up a couple of hundred feet; a C motor is definitely the best choice for this model.
The Thunderbird's motor ignites (Click to enlarge).
Big Bertha clears the rod (Click to enlarge).
My Alpha waits patiently on the pad (Click to enlarge).
The 60's style Alpha heads up the rod (Click to
enlarge).
I flew six models, the first being my Centuri Thunderbird clone. Powered by a C6-5, it got some serious air, but the parachute shroud lines tangled on the fins, resulting in a hard landing. Fortunately, no damage. Flight #2 was that of my Estes K-42 Stinger clone, which went surprisingly high on an A8-3. Its orange plastic streamer brought it down to a soft landing fairly close to the pad. Big Bertha was up next on a B6-4, making her usual slow and graceful ascent into the blue sky. An Estes Alpha with the modern blue and red decor followed Bertha, burning yet another of my plethora of A8-3's. Flight #5 was also that of an Alpha on an A8-3, this one with a 1960's paint scheme. Unfortunately, its shock cord burned through and the body landed hard on the grass, breaking a fin into pieces. The damage is repairable, though the fin will need a new coat of paint after I glue it back together and fill the cracks.
Marc's Diamondback leaves the pad (Click to enlarge).
The first stage motor of the Helios ignites (Click to
enlarge).
The Estes Ready-To-Fly Helios was my last rocket to take to the air, augmented by an Estes BT-60 booster stage and a keychain camera taped to the sustainer. The C11-0/C6-5 lofted it to the highest altitude of the day, but I grew concerned when I saw the model descending straight for the road. Visions of the rocket and camera being crushed under the wheel of a car danced before my eyes; thankfully some early luck of the Irish guided the bird to a landing on the grassy median between the north and south bound lanes. I had hoped to get some nice video of stage separation, but there was only a couple of frames, none showing the booster falling away. However, I did get some good shots of the chute wadding being ejected and a segment showing cars passing close to the rocket as it awaited recovery.
The parachute wadding falls away from the rocket (Click to enlarge).
Liberty launches a TARC rocket on a practice flight
Earlier this week, I was suffering through a cold; today, after some decent rest, I felt well enough to join Duane for a trip out to Pegasus field and watch some TARC practice. Nate was out there with his Liberty teams, and they had already put a bird in the air by our arrival at 10 AM. The Liberty teams are very efficient; in the two hours they were at Pegasus, they set a good pace, completing a total of six practice flights. They had a bit of trouble hitting the altitude mark, with one broken egg and a few kicked motors, but the Liberty teams walked off the field with their rockets intact. This was not true for the Falcon Rocketeers, whose primary rocket was destroyed when it came in ballistic on its first flight - shredded body tube, egg yolk all over the place, and an altimeter that seems to have suffered major electronic brain damage. Not daunted by the buzzard now circling overhead, the Falcons switched over to their backup rocket and made four successful flights with this model; if the buzzard was searching for more rocket corpses, it was disappointed.
Nate shows a team member how to connect an igniter
(Click to enlarge).
A Liberty rocket leaves the rail (Click to enlarge).
Launching Liberty's "Atomic Bomb" rocket (Click to
enlarge).
The Falcon Rocketeers' primary rocket on its way up
(Click to enlarge).
And after it came down... (Click to enlarge).
The Falcon Rocketeers at work (Click to enlarge).
Falcon's backup rocket poised for launch (Click to
enlarge).
The performance of the blue and green backup rocket was puzzling to the young rocketeers, as no matter how much weight was added or taken away, it veered sharply into the wind, ending up about 100 feet shy of the altitude goal. It was as if the rocket was defying all logic, absolutely refusing to go higher than 750 feet. The team's last flight was around 2:30 and yielded a disappointing peak altitude of 730 feet; the Falcon Rocketeers left the field musing on the mysterious behavior of their backup and laying plans for the construction of new rocket to replace the destroyed primary. However, there was one bright spot - they achieved a new record in prepping and launching the rocket for the final flight in under 20 minutes. Duane, the "benevolent dictator", was pleased.
The Red Grasshopper on the pad (Click to enlarge).
The Red Grasshopper starts its 1st flight (Click to
enlarge).
Marc is becoming a regular at these Saturday launches, and he was there today with his children and his retro "Red Grasshopper" rocket. He also intended to fly a Semroc Orbital Transport, but that model suffered a mishap in the car on the way to the field; hopefully, it will fly at our next launch. The Red Grasshopper is a crowd pleaser with its sci-fi looks and slow takeoffs - its first flight was picture perfect, but the parachute did not deploy on the second, resulting in a very hard landing. There were a few pieces, but it think it is repairable, especially given Marc's building skill.
My Estes Stinger awaits its 1st flight (Click to enlarge).
The Viking 7 is propelled upward by dual B6-4's
(Click to enlarge).
I couldn't imagine a sunny day at Pegasus without flying a few of my birds, so I brought four. The Centuri Nova clone and the Estes Stinger would make their first flights, joining my Rocketarium scale model of the Viking 7 and the battle-hardened Little Beth X-2. I started with the Stinger, which put in a good show on an A8-3. All seemed well until I inspected the model after landing, when I discovered the paint on the leading edge of one fin had been knocked off by the nose cone snapping back at ejection. Muttering a curse at Estes for too short shock cords (and at myself for not replacing it with a longer one), I put the model back in the SUV; it now resides in the minor repair box, awaiting a paint touch up. No biggie, but still annoying.
The Centuri Nova streaks up into the sky (Click to
enlarge).
Little Beth starts up the rod (Click to enlarge).
Next was a flawless flight of the Viking 7, riding the fire of 2 B6-4 motors into the sky. The clone of the Centuri Nova stunned everyone with its speed - a light, small rocket really moves when you have an A10 motor stuffed in its rear. Then came time to fly the rocket that never ceases to pose a challenge to me - the Little Beth X-2, loaded with 2 B4-2's in the outboard pods of the 1st stage, with a B6-0 sandwiched between, and a B6-4 in the upper stage. The plans for this model - Estes Design #57 - call for a C6-0 rather than a B6-0 in the lower stage, but I, an experienced rocketeer of many decades, knew that a B6-0 would work just as well, and also save me a few yards of walking. Never mind that all past flights of this model that used a 1st stage motor combo different from that specified in the plans have failed spectacularly - today would be different.
Yeah, right...
The Quest Q2G2 igniters had no problem igniting the 3 booster motors, and Little Beth X-2 streaked off the pad, the keychain camera recording the action from the rocket perspective. All went well until the B6-0 burned out, at which point the rocket started gyrating wildly; the first stage then fell away, the gyrations stopped, and the model continued up to a lower than expected apogee. There was no ejection charge, and I watched in horror, fully expecting the model to dive straight for the ground. But I suppose the rocket gods took pity, for Little Beth's upper stage descended horizontally, spinning rapidly about the long axis. This slowed the fall, and the rocket survived its landing with no damage. The post flight inspection showed that the B6-0 in the first stage had been kicked, and that the B6-4 in the upper stage had not ignited, which explained the low altitude and no ejection charge. I was still puzzled by the gyrations just before the stages separated, and hoped that the flight video might provide some clues.
A few hours later, I had uploaded the video to my computer and was looking through the individual frames. The video seems to indicate that the 1st stage was partially separated from the upper around the time the B6-0 burned out, as you can see part of the coupler connecting the stages. That would explain why the upper stage motor did not ignite, but was the separation caused by gyrations or by the hot gases from the depleted B6-0 (you know, the gases that were supposed to ignite the upper stage)? My best guess is the latter, and I suspect the gyrations were caused by a thrust imbalance between the B4-2 motors in the side pods (which burned for 0.2 seconds longer than the B6-0), aggravated by the camera taped to the side of the rocket. Once the first stage falls away, the ground is now longer blurry in the video, verifying that the gyrations had stopped.
After B6-0 burn out - note the exposed coupler (grey tube just beneath the black fins - Click to enlarge).
B4-2 motor burn out (Click to enlarge).
1st stage separation - note that the B6-0 motor in the center tube is no longer there (Click to enlarge).
The 1st stage falling away (Click to enlarge).
My take-away from this flight is that the center motor of the 1st stage must have a burn time equal to or greater than that of the motors in the side pods. A C6-0 burns for 1.8 seconds, 0.8 seconds longer than the B4 motors, so it is the recommended choice. And I think I will use the C in future flights, even if it does mean more walking - Little Beth has had more than enough hard landings.
