Sunday, April 29, 2007

April 28 launch

Had another launch yesterday with the crew from August. It was a beautiful day and we had some beautiful flights. The photo above shows my RPG rocket (on the right) with an Estes Space Bus and an X-15. The RPG's nose is made from cardboard decoupage cones and the ring fin is the cardboard tube from a roll of packing tape.

I had taped the nose cone shut for painting, and like an idiot I forgot to take the tape off before launch. The RPG had a beautiful boost to about 300 feet, at which point the ejection charge blew out the motor and the rocket pranged into some woods on the other side of a hill! Of course I had to paint the damn thing green. So I figured it was just gone. Either we'd never find it, or it would be total hamburger if we did locate its remains. But to my amazement the rocket was found intact. The body tube is a little bent, so the nose cone is no longer in perfect alignment with the tail (as you can see in the above photo), but it turned in two more beautiful flights--without tape.

This was my first time launching off a multiple pad setup, which allowed us to have some races. Here the Space Bus scoots off the pad on a 1/2A much faster than the D12-3 can get the RPG moving.

One of my star performers for the day was the Currell Graphics V2, which turned in three great flights. On the first flight the parachute failed to open but the rocket came down fine. I realized that this is a paper rocket and the parachute is really overkill. So I took it off for the next two flights, and the rocket came down just fine both times.

Yesterday was my first time to launch the V2 on C motors, and it performed beautifully.

The real star of my show was the Cheese Wheel (formerly known as the Laughing Cow saucer), of which I have two, one for 18mm motors and one for 24mm motors. I launched the 18mm one by itself on a C, launched them both together with CHAD staged D12-0 to A8-3 and again with D12-0 to C6-3. Perfect flights every time, slow and noisy--real crowd pleasers.

This was my first time staging anything, and I'm very happy with how well it worked.

This is not my rocket, but one of my rockets has a part in its story. This is a giant rocket made from a PET soda bottle with an 18mm motor mount in what was the bottle's spout. The trouble is, this thing is too darn big for an 18mm motor to push. She turned in two flights on C6s. Both times she only made it up to about 20 feet before heeling over and flying right into the ground. Neither crash was very violent because the rocket was traveling so slowly and such at a low altitude to begin with.

After some judiciously applied masking tape patched the damage from the first two crashes, we were discussing the possibility of a third launch. I volunteered to use the 24mm Cheese Wheel as a booster to get the thing moving fast enough that a C motor might do some good.

So we did that. Problems started as soon as this Frankenroc cleared the pad. As in the first two flights, it was going too slowly for the fins to stabilize it. It may look fast in the photo above but actually it was moving very slowly, about the speed of a Frisbee. So it started to lean over, and the leaning continued as it accelerated. By the time it was going fast enough for the fins to keep it flying straight, it was pointed horizontally.

Here we are right after booster separation. The Cheese Wheel is the black dot behind the PET rocket. Notice that the latter is now pointed down. It flew right into the hillside under thrust, this time from an altitude of perhaps 75 feet.

The aftermath. This is the coolest smashed rocket I've ever seen. Often the nose cone is trashed and the body tube may have one or even two strong bends, but this thing is on another level entirely. A couple of the bends in the body tube are foreshortened in this view; it actually buckled in four different places. The last remains of the red nose cone are peeking out the front. We decided it looked like a sad vulture.

Naturally, the Cheese Wheel came back with no damage.

Well, that's all for now. No more blogging for me until the dissertation is done.

Sunday, April 22, 2007

Back to the future

Hi folks. Been a bit busy with the dissertation. Still am, actually. But stuff has come up. Last week I was wandering around the local Half-Price Books and I found a copy of The Conquest of Space, by Chesley Bonestell and Willy Ley. It's an early 50s printing, the sixth or seventh I think, but I don't care. I bought it because it's awesome, not because I'm planning on selling it someday. I picked up a cheap copy of the movie The Conquest of Space on DVD last fall, and I'm ashamed to say I haven't gotten around to watching it yet.

Also, there's a rocket launch at the park this coming Saturday. I've got a jillion unbuilt things in the closet, but I don't have time to build any of them. Mainly because I'm not planning on building any of them stock. For example, my Estes Big Daddy is going to be a stubby, camera-carrying, probably dual-motored V2. But that's going to take planning and work.

I do have an idea I want to try. I found some killer cones at Michaels last December. They are cardboard cones that use as bases for Christmas tree angels, I think. Irritatingly, the Michaels online catalog doesn't seem to have them so I can't show you a picture. The cones are about seven inches long, three or four inches across at the base, and a bit less than an inch across at the top. If I get some serious dissertating done this week, I might cannibalize the Star Dart or Sizzler to build a cone-finned rocket.

And hell, if I run out of time I'll take the Turd Burd and a Laughing Cow saucer and still have a wonderful time. Stay tuned for launch photos...I hope!

Tuesday, November 21, 2006

Pushing the envelope

Thanks for stopping by. As you can tell from my post rate, or lack thereof, it's been a dry couple of months. I've got this pesky dissertation thing to finish by May, so my rocketry has to take a back seat for a while.

Still, something has come up that I am compelled to write about. I've never been a huge fan of nFNCs. It's nice to have a few in your collection for sport launching, but I've always been more attracted to scale models and oddrocs. I am always trying to think up new ways to make rockets fly--either fly unconventionally, or fly conventionally but look strange doing it. I know I'm not alone in this; that's probably what half the rocketeers in the world are up to.

But most of the time there is nothing new under the sun. The demands of stable flight in an atmosphere put fairly strong constraints on what a rocket can be and still work. Over the past few decades rocketeers have been pushing back at those constraints, or trying to find ways around them, but it's not very often that I see a rocket that just blows me away in terms of originality.

Therefore I was intrigued to see this thing (below) put up as a possibility in EMRR's Spaceship Design Challenge.

It's just...weird. Whatever my previous idea of the limits of aerodynamic form, this thing is outside of them. I love it.

And somebody actually built it and made it fly. The designer calls it the Annulus, appropriately. Here are some pictures I stole from EMRR.

My next big rocket-building fest is a ways off. Months, probably. But whenever it comes around again, I really want to try building something like this.

Sunday, September 10, 2006

Experimenting with video capture

I mentioned in the last post that I had videos from yesterday's launch but no photos. I shot the video with a Pure Digital Point & Shoot video camcorder ($129 at Target). Today I downloaded VirtualDubMod and an XviD codec and started playing with the movies.

First up: image capture. My success with catching the rockets at liftoff with the digital camera has been fair-to-middlin'. With VirtualDubMod I can go through the launches frame-by-frame to get the pictures I want, and to see exactly what happened during the interesting flights.

For example, the disintegration of the Serve 'N Store saucer (above) was too quick for the eye to follow, but not for the camera. In the fourth frame, you can see the motor has flown through the saucer and blown the plates apart. They fluttered down harmlessly--and unharmed--while the motor took off on its own. Fortunately the motor was moving fast enough and had burned enough propellant to be stable, or things might have gotten too interesting.

The image captures serve another, unexpected purpose. It turns out that I never got any photos of the Evil Toothfairy's Flying Laboratory of Dental Torment after I finished building it. Then it was utterly destroyed on its first flight. The only pictures of the whole rocket are the frames of the liftoff (above). In the second frame, you can see a little smoke coming out a little over halfway down the length of the rocket. That's not a CATO in the making, that's the gap between the end of the body tube and the ring fin, which was suspended well behind the body tube on four pylons. You can see this more clearly in the final frame.

The Laughing Cow saucer had no problems. It's a great little performer, and I'll probably have it forever. It's cardboard, so it's relatively burn-resistant; it's waaay over-stable, so it's not going any direction but up; and it tumbles down, so it always lands near the pad. I suppose some vicious combination of freak gust and rocket-eating tree could do it in someday, or a full-on explosive CATO. It's a great little rocket, and I love it.

I love the Laughing Cow saucer, but I Luh-huh-huh-OVE the Thunderhawk. It's just a big, beautiful, badass flyer. Vicki, my long-suffering spouse, said that its flights were much cooler than she expected, but that they freaked her out with all the noise and smoke. Psshhh...YEAH! That's the idea.

Unfortunately, on the 'Hawk's second flight of the day, the chute did not deploy completely and she came down a little faster than intended. That's how the fin cracked. I'm sure all the serious BARs out there will think I'm a dumbass when I admit that I've been flying it with the stock Estes recovery system. I always planned to upgrade to a Kevlar, nylon, and Nomex system someday, and that time is now. Fortunately, the damage is minimal and easily fixed, so I got off pretty easy. Just gotta get her fixed up and back into the air.

Saturday, September 09, 2006

Another launch!

Just got back from another satisfying launch, only my second as a BAR. The Thunderhawk logged two more flights, both successful, although she did crack a fin on the second landing. The day's workhorse was the Laughing Cow Saucer, a small flying saucer made from a cardboard cheese container. It had three perfect flights on 18mm motors.

I also had some less-than-perfect flights. I built another Hefty Serve 'N Store saucer to replace the first one, which I gave away after the last launch. The new saucer only flew once today, if "flew" is the right word. I relied on the friction fit to keep the motor in place. I should have used a few turns of tape, like I usually do. Right after it left the launch rod, the motor flew out of the saucer. The two plates got separated and a little scorched, but they didn't melt and I was able to put them back together with no problems. The naked motor probably cleared 300 feet. I'm sure it would have gone completely out of sight if it hadn't burned half its propellant getting free of the airframe.

I also launched a couple of garbage rocs. The Fiber Boost had a couple of unstable flights before I realized that it needs some nose weight and grounded it. The Evil Toothfairy's Flying La-BOR-a-tree of Dental Torment had a name longer than its flying career. As with the Hefty saucer, the problem was a lack of positive motor retention. The ejection charge blew the motor out of the fuselage and failed to deploy the streamer. The rocket pranged, hard, from several hundred feet up, onto asphalt. It was utterly, utterly destroyed. I really wish I'd taken the camera with me when I went to recover it. It was just a hilarious pile of smashed debris.

In fact, I neglected to take any photos today, other than the reference photos taken by our new video camera. But I did get some decent videos, including this one.

Thursday, September 07, 2006

A trilogy of Toddities

In the last post I mentioned that my brother Todd was prone to having interesting launches. It is time for the world to know his story, so here I will present his three best.

Chronologically, the Wizard must have come first. Actually, there were three Wizards, one each for Todd, our cousin Michael, and me. We were all between the ages of 8 and 14 at the time, I'd say--prime rocket-experimentation years. We probably bought the rockets with the dough we earned roguing fields for Uncle Robert. We all got them together, and we undertook the construction together, too. Todd and I were used to building rockets for 4-H, which could take a couple of weeks. Michael introduced us to ways to speed things along, like mixing a little CA in with the Elmer's to make gluing and filleting the fins into one messy but fast step. After a morning under his tutelage, I said, "Wow, this is really going fast. We ought to be ready to launch in another day or two!" Michael looked at me like I'd just thrown up on myself or something. "Day or two!" he snorted. "I don't know about you, but I'm launching this rocket at three o'clock this afternoon!" And we did.

But we had some problems. My rocket ejected its motor at apogee, but not its nose cone or streamer. Once it went into lawn dart mode, we lost sight of it. After a few minutes of scanning the sky and the ground, we saw it about a hundred yards off, sticking straight up out of the ground. That was the prang that caused me to cut it down into the Izard.

Todd was much worse off. The glue on his rocket was not dry when we went out to launch, but he was not deterred. One of the fins fell off before he even got it on the pad, but nothing could crush his indomitable spirit. He launched. When a 3FNC becomes a 2FNC, it does not make for a pretty flight. Todd's Wizard engaged in wild corkscrews, shed another fin along the way, hit apogee at probably no more than 75 or 100 feet, and started gently tumbling down. It was coming down so straight and slow that Uncle Robert just about caught it in the air. However, as his hand was about to close on the body tube, the ejection charge went off. I guess the glue on the shock cord mount wasn't dry either, because the nose cone, shock cord, and streamer fired out of the rocket like a kite-tailed bullet, and the body tube blew backward, leaving Uncle Robert's hand to close on empty air. All in all, it was one of the most arresting flights I've ever witnessed.

In a strange turn of events, another late ejection saved Todd's Strike Fighter a few years later. We had both built Strike Fighters, and we adored them. However, when we went to launch them the first time, we found that we'd expended all of our B and C motors. All we had were A8-3s, which were not recommended for the Strike Fighter because of their low thrust. I decided to save my Strike Fighter for another day, but once again, Todd's courageous disregard for the well-being of his rockets provided us with a spectacular flight. His Strike Fighter huffed up to maybe 60 or 70 feet, heeled over, and headed straight for the ground. It was literally no more than two feet off the ground when the ejection charge blew. This had the effect of firing the flat-edged nose cone down into some tall grass, and the reaction force essentially stopped the rest of the rocket dead still in the air, after which it also fell to the ground. This was equivalent to dropping the rocket from a height of two feet into thick grass, so there was no damage whatsoever.

I am pretty sure that was the same day that Todd's Nado made it's first, and as far as I can remember, only flight. The Estes Tornado was a short fat little rocket that was designed to break in half at ejection, with each half carrying an uneven number of the rocket's fins and coming down by helicopter recovery. Todd chopped the Nado down into an even shorter, large-winged Buck Rogers type spaceship. Of course, it was nowhere near stable, as we discovered when we launched it. Todd's wet-glue Wizard had ascended in a tight corkscrew, but the Nado zoomed around in ever-widening gyres like a time-lapse movie of a circling vulture. It was probably the least stable flight I've ever witnessed. But it came down in one piece, and as far as I know it's still up in our old room.

Maybe we should give it another whirl.

Wednesday, September 06, 2006

My first fleet

When I was a kid, I was in 4-H. I learned all kinds of stuff in 4-H. Some of those things, like public speaking and basic photography, are central to the stuff I do now. Others, like horticulture and raising chickens, are on hold until we get to someplace with a yard (and tolerant neighbors). But those are all things I did through 4-H. They're not the reason I was in 4-H.

I was in 4-H for rockets.

I got my first rocket, an Estes Harpoon, when I was nine, the same year I got my first pocket knife. Harpoon had missile stylings and decals and would fly to about 500 feet. Dad built a launch system out of wire, alligator clips, and a doorbell buzzer. We would drive the pickup just a few hundred feet from the house to a grassy patch of unused land, hook up the launcher to the pickup battery, and launch it. It was the best thing ever.

Other rockets followed. My second was an Estes Magician, which flew to over 1000 feet on a D motor. Dad and I launched it in a pasture on a calm day. It may have been calm on the ground, but there was some serious wind blowing at 1000 feet, and after the rocket popped its parachute we chased it for more than a quarter mile. I did a science fair project on model rockets, comparing the performance of rockets with square, unsanded fins to those with fins that had been sanded into an airfoil shape and sealed with wood sealant. The sanded-and-sealed rockets flew twice as high as the rough ones. I tracked them with a homemade alititude tracker made from a protractor.

In 4-H, the rockets not only had to fly, they had to look spiffy, too. They were to be entered in the county fair and judged on appearance. So we spent a lot of time building them and putting on paint and decals. My cousin Michael introduced me to another school of rocketry, in which you built the thing in the morning, launched it in the afternoon whether the glue was dry or not, and painted it when and if it came back. I don't know that we ever permanently lost a rocket. Michael's Scout disappeared on us, but Michael found it floating in Uncle Robert's farm pond a while later. The fins had fallen off, but the fuselage and nose were intact. The next summer we taped up its ejection port, launched it at night, and watched it explode. It was awesome.

Hands down, our favorite rocket was the Estes Geo Sat LV. It was a scale model of a satellite launcher, loosely based on the Titan family, with a clear plastic payload section that contained a little satellite. It looked rad, and when it took off.... The Geo Sat was more than two feet tall, which was not enormous but still much bigger than any other rocket in Wedel experience. We were used to the Harpoon and Magician and Wizard, which just sorta vanished off the launch pad when you pressed the ignition button. Geo Sat lifted off slowly and majestically, with lots of fire and smoke and noise. It felt like launching a real rocket.

Here's a list of the rockets I built when I was a kid (i.e, between the ages of 9 and 16), in rough chronological order. All of them were Estes makes, because that's all I could find at the hobby store.

Geo Sat LV
Space Shuttle
Strike Fighter
Dragonfly (boost glider)
Titan IIIE - never flown
Mini Mars Lander - never flown
SDI Satellite - never flown

The science fair fleet consisted of three rockets of the same make, whatever nFNC was cheapest at the time. I think they were Stingers.

I definitely joined the Estes Aerospace Club at one point and got a Viper out of it, but I honestly can't remember if I built it or not.

My brother Todd had a Tornado that he kitbashed into the extremely short, large-finned Nado. It was not stable, but the one flight was entertaining. Actually, I should do a whole post on Todd's um, interesting launches (and now I have). My Wizard pranged and crumpled the front of the body tube, so I chopped it down to an Izard.

Once in my late teens or early twenties my brothers and I bought Dad a Mean Machine. We launched that thing over and over.

Incidentally, all of these rockets are still in existence, propped against an usused wall in the upstairs bedroom that was mine and then my Todd's. I imagine that the rubber band shock cords and plastic parachutes could stand to be replaced after 15-20 years of inactivity, but the rockets are flyable. In fact, maybe we'll dust them off this Christmas and let them go.

All of the rocket images in this post started their digital careers on Sven Knudson's awesome, encyclopedic Ninfinger site. If you want to blow a few hours poring over old rocket catalogs, this is the place.