Estes released a nice ready-to-fly rocket a few years ago called the Snitch. Basically, it's a plastic UFO saucer that climbs into the sky, fighting drag the whole way. When the engine burns out, then it flips over and floats back down to earth for a soft landing. It's perfect for night flights, going slow enough to see the bright engine flame yet staying low enough to remain visible (it's day-glo green). We've also staged ours by taping a second motor to the first. Lots of fun, and one of the best Estes releases of recent years.

In the extended entry is a nice photo of three Snitches taking off in formation. Thanks to Steve B. for posting it to the Alt.Binaries.Model.Rockets newsgroup. more...

Posted by: Ted at 05:37 AM | category: Rocketry
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Well, we drove to Culpeper, and things weren't looking good. Flags were standing straight out from the poles, and despite the weatherman calling for 'diminishing winds', the trees were whipping around pretty good.

When we pulled up into the field, there were a total of four vehicles there. Not good at all. Nothing was set up to launch, it was just too much wind. So we visited with some rocket friends we haven't seen in a while, and talked about new projects and 'EX' rocketry.

'EX' is a part of rocketry where you actually make your own solid propellant motors. You take the various chemicals and additives and mix it up like you would a cake, following a recipe, and you wind up with a slug of homemade rocket propellant. It's similar to the process that Homer Hickam and the Rocket Boys did in the movie October Sky. I've never done 'EX', and although it fascinates me I don't know if I ever will. It would certainly be a royal pain to get the permits where I currently live. Maybe someday, but for now I'm satisfied with buying and flying the commercial stuff.

Ken, the owner of Performance Hobbies was showing off this neat little beastie. It was a 3" diameter rocket, completely built of carbon fiber veil. Very light and incredibly strong. In fact, the rocket was built to take a 3" motor, meaning that this ~5lb rocket was designed for a motor that can lift 150lb rockets. I have no idea what the max speed would be, but I don't think mach 2+ would be out of the question.

We've got the cell phone number of one of the guys who'll be there tomorrow. We'll call in the morning and see what it looks like before heading down again. It's supposed to rain tonight, and today was supposed to be the better weather day.

Oh well, Mookie and I had a nice day together, and we got to visit with friends. Not at all a wasted day.

Posted by: Ted at 02:16 PM | category: Rocketry
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Mookie and I will be headed out in a while for today's launch. It's a two-day event this month, held in Culpeper, Virginia. According to the local weather, today is going to be the nicer half of the weekend.

Air Munuviana is scheduled to fly today on my new I90 hybrid motor. Woot!

Directions here. The open invitation still stands, no charge for spectators, and if you do make it out stop by and say hi. Just look for a red Mazda pickup.

Posted by: Ted at 07:35 AM | category: Rocketry
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pictures in the extended entry, popup style

The winds never did calm down, but it was still a beautiful day for rockets. Temperatures were in the mid-40's and everyone stayed bundled up, but it wasn't too bad. It helped that there wasn't a cloud in the sky, so the sun was warm. We had a great turnout, including a dozen or so high school teams making practice flights for the Team America Challenge, and two kids doing documented launches for Science Fair projects.

I personally only made one flight, and that was the maiden launch of our "Build It" rocket, the Fat Boy. It was a nice flight, but it weathercocked into the wind quite a bit and didn't get as much altitude as it should have (maybe 500'). It was recovered without damage and will fly again.

The team I'm mentoring was there and ready to go. They brought two completed rockets, and made three flights total. On their first flight, they had perfect ignition of all three first-stage motors, perfect ignition of their upper stage motor, and overshot the target altitude of 1250', hitting 1588'. That's not too bad, because it's easier to make a rocket go lower than it is to make it go higher. Both eggs were recovered in perfect condition, and they learned a lesson in picking the correct size parachute for the wind conditions (they had a long walk to recover the rocket).

Next flight for them was in their second rocket, and this time they used a smaller upper-stage motor. Another perfect ignition, but this time they didn't get enough altitude and had a problem with staging and the booster lost a fin when it separated.

Their third flight (first rocket again) was perfect except that at some point the altimeter reset when the battery came loose, so they don't know exactly how high it went. On all three flights, the eggs were recovered unbroken. They'll be ready for their qualifying flight on April 2.

Last year, there was probably an overall 80% failure rate for Team America flights. Today, I'd say there was a 90% success rate, and most of the malfunctioning flights happened at the end of the day when teams were rushing to get in one last flight. I manned the safety check-in table for the last hour, and the variety and quality of the rocket designs was striking.

Great day. Great fun. more...

Posted by: Ted at 08:28 PM | category: Rocketry
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The sun is out, the sky is clear, the field is dry, winds are diminishing and we're gonna fly some rockets! Pictures later.

Posted by: Ted at 08:19 AM | category: Rocketry
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Info about the Team America Rocketry Challenge can be found in this old Rocket Jones post.

The team of high school students I'm mentoring will be going to our rocket club launch this saturday. Yesterday they finished up final details on their first rocket, and she's ready to make her maiden flight. The students also got a good start on their second rocket, this one using fiberglass for fins and having a different fin geometry. As per the rules of the contest, both rockets are two-stagers designed to carry two fresh hens eggs to 1250 feet and then parachute them back safely.

The high school team that won the TARC last year has been busy since then, designing a payload experiment and rocket that must reach an altitude of one mile. They'll travel to NASA's Marshall Space Flight Center in Alabama for an April launch along with nine other teams, and the winning team will get to spend a week at Space Camp.

Also, our Fat Boy will finally be making her maiden flight too.

Posted by: Ted at 05:45 AM | category: Rocketry
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A couple of days ago I linked to the Gates Brothers website, for a peek at some amazing projects that they fly.

This time around, meet Wedge Oldham, who doesn't just build and fly big scale versions of famous rockets, he builds 'em bigger than original!

I look positively Orion.

Posted by: Ted at 11:33 AM | category: Rocketry
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Eric and Dirk Gates are famous in rocketry circles for their big-time projects. You may have seen them on the Discovery Channel show Myth Busters, when they were the 'experts' brought in to help on the episode about a car with rockets mounted on the roof.

They have an awesome website, full of pictures and good information and video clips that have to be seen to be believed (including on-board cameras). It's so popular, and there is so much to see there, that they routinely shut down midway through each month for excessive bandwidth. It's up right now though, you really should visit, and if you have a high-speed connection, be sure to check out the videos.

They've also put up Dirk's son's 8th grade research project on spin-stabilization of model rockets, which took 1st place in the California State Science Fair. Like I said, impressive stuff.

Posted by: Ted at 08:29 PM | category: Rocketry
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A t-shirt gift for the scientifically-inclined youngster of any age.

As a matter of fact, I am a Rocket Scientist.

Posted by: Ted at 06:00 AM | category: Rocketry
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1 That's great! Almost makes me wish I had a kid so I could get him one!

Posted by: Victor at February 26, 2004 10:34 AM (L3qPK)

2 Thanks, dude! I'm going to have to put you on commission.

Major redesign of the Web site is happening this weekend if I can ever get the ASP code working right.

Love your blog, check it daily when the boss isn't watching. See you at Great Meadow next month?

Posted by: Doug Pratt at February 27, 2004 10:06 AM (D6ZyB)

3 You made my day, Doug! Great Meadows is a go, and the TARC kids I'm mentoring are planning to be there with at least one rocket for test flights.

Any word on the Sky Ripper J? I've got the parts for an upscale Yellow Jacket just begging for Level 2 cert.

Posted by: Ted at February 28, 2004 01:26 AM (2sKfR)

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A t-shirt I designed a few years ago about model rocketry.

(in the extended entry) more...

Posted by: Ted at 05:16 AM | category: Rocketry
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Des-what?

Descon stands for Design Contest, and it's an online rocketry event held three or four times a year. People from all over the world enter their original rocket designs, and folks vote for their favorites. Prizes are donated by various hobby businesses and are awarded. Sometimes there's a theme or specific requirements, sometimes it's a free for all.

Mookie won it once, when she was 10 years old. I believe she's still the only kid and only female to ever take first place. In the extended entry is a photo of her posing with her prize. more...

Posted by: Ted at 09:03 AM | category: Rocketry
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Yesterday afternoon after work I met with the team of high school students that I'm mentoring for this year. Five city kids - three boys and two girls - who are going to design, build and fly a complex rocket with the hopes of earning scholarship money.

This is a bright and motivated group. They've already settled on their design and will be building two versions, one with balsa fins, and a second with fiberglass fins. Construction started last night, and we also went over some rocketry basics, simple aerodynamics, and I gave a quick demo on the flight simulation software they'll be using.

The quickie version of the task they're trying to accomplish is that they have to build and fly a two-stage rocket that will fly as close as possible to 1,250 feet in altitude (measured by an electronic altimeter carried onboard), and get it back. The payload they have to carry aloft is two fresh eggs, and they have to bring them back to earth unbroken.

They're competing with almost one thousand other teams from all around the US for scholarship money. The contest is sponsored by the Aerospace Industries Association and NASA is heavily involved.

Some of the coolest perks from last years contest was for teachers to attend NASA educational workshops, and the top ten teams were given the opportunity to design science experiments that were carried aloft in NASA research rockets. Teams also got to meet shuttle astronauts and Homer Hickam, former NASA engineer and author of Rocket Boys (October Skies). Other guests attending the finals included Senator Enzi from Wyoming (a rocketeer and space proponent), as well as the honchos from NASA and Boeing.

For more information and details, please check out the rocketry links over on the right hand column, my Rocketry category, or this post.

Posted by: Ted at 08:39 AM | category: Rocketry
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One of our fellow rocketeers is the Laboratory Director and Chief Metallurgist at the Chamberlain/Scranton Army Ammunition Plant. As time allows, he's running a series of tests on common hobby rocketry materials and construction techniques. Test descriptions and results can be found here. Even if you aren't into the technical aspects of it, some of the equipment and methodology is interesting.

Posted by: Ted at 08:26 AM | category: Rocketry
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Event Sold Out almost two months ahead of schedule.

Posted by: Ted at 07:59 PM | category: Rocketry
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I do a summary of our family's rocket activities every year*, and this year y'all have the chance to look it over if you'd like. *yawn* It's in the extended entry.

*We've kept complete records of every flight we've ever made. It's a good way to gauge our progress as we advance in this hobby, and helps us to figure out what happened when things go wrong. more...

Posted by: Ted at 02:08 AM | category: Rocketry
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If you remember the old rocket companies of our youth, you might want to check out these shirts with the classic Centuri logo.

Or these cool SciFi designs.

Hmmm... "Space Cadet" or "It's the Law"... "Mad Genius" or Still Life. Too many good choices.

He's got some very nice celtic designs too.

Posted by: Ted at 06:55 AM | category: Rocketry
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Here's a simple and inexpensive way to get a fair estimate. There are three diagrams, so expand the extended entry to read the surprisingly easy method we use.
more...

Posted by: Ted at 09:45 AM | category: Rocketry Resources
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1 Mark I Eyeball only has three measurements, tho: High, Really High, and Hey, God! Little help?

Heh. OK, that's my lame attempt at rocket humour. And I haven't even taken any cold medicine!

Posted by: Victor at January 03, 2004 12:29 PM (16A49)

2 Dang, I thought I invented that device!
After your post about Air Munuvia's maiden voyage I wondered how you could determine how high it went. "Easy," I thought, "just measure the vertical side of the right triangle by looking along it's hypontenuse from a known length of the horizontal side!" (I never got around to writing up a table, though.)
This is as disappointing as the time when I was in K-mart, aged 9, and discovered that my battery-heated socks idea had already been invented.

Posted by: Tuning Spork at January 03, 2004 07:04 PM (QMRJ/)

3 Also, that system is accurate only if the rocket climbs perfectly vertically. It would be a good idea (if you really want an accurate measurement in the case of a competition, say) to have someone else with a perpendicular view to measure the angle from the launchpad to the rocket at apogee.
If the rocket curves toward the tracker then the reading with show that the rocket had reached higher altitude than it actually reached; and it curves away from the tracker then the reading would understate the true altitude.

Posted by: Tuning Spork at January 03, 2004 07:15 PM (QMRJ/)

4 psst... Spork... last paragraph.

Posted by: Ted at January 03, 2004 07:42 PM (2sKfR)

5 D'oh! I guess I stopped reading too soon.

Posted by: Tuning Spork at January 03, 2004 11:00 PM (QMRJ/)

6 Easiest way to tell how high a rocket went is to launch it indoors.

WhooshCRUNCH!

"About eight foot six, wouldn't you say?"

Posted by: Pixy Misa at January 04, 2004 08:09 PM (kOqZ6)

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I know, it's *yawn* to most of you. But it's not often I get to act like Horschack.

Victor left a comment on my post about the upcoming Bowling Ball Loft contest. He was referencing part of the rules:

I took a look at the rules, and this intrigued me: Use a launch rail, tube or tower. Rods are prohibited due to past bad experience.

And he asked:

Can you explain the difference between the four launch pad configurations (apologies if my terminology is not correct) and what kind of bad experience they may have had with a launch rod? (I realize that might be speculation on your part.)

No speculation needed, I know exactly why they don't allow the use of launch rods in this situation. First a little background:

An unguided rocket (like we fly) has to be moving at a certain speed for the fins to have a stabilizing effect. Usually itÂ’s around 40mph, although a lot of different factors can make a difference one way or another. Since hobby rockets are launched very nearly vertical, we use different ways of making sure that the rocket stays pointed straight up until itÂ’s moving fast enough for the fins to take over.

All of these assume that the launch pad itself is stable. Good wide legs, low center of gravity, anchored to the ground or hefty construction; all of these combine to ensure that the launch pad wonÂ’t tip or tilt when the thrust of the motor kicks it. Attached to the launch pad itself will be the rod, rail, tube or tower.

The oldest method is the launch rod. Most commonly used for the smallest model rockets (1/8” x 36” long), it doesn’t scale up well but is still used - up to 1” diameter rods around 12 feet long. The problem is that when more power and weight are used, the rod tends to ‘whip’ which can fling a rocket off vertical. Not a biggie with a nine ounce model rocket, but it can be very dangerous with a nine pound rocket. A ‘launch lug’ is used, which is just a length of tubing glued to the rocket that slides loosely over the rail. On smaller rockets, the lug looks like a short piece of soda straw.

The launch rail is quickly becoming the standard method of launching bigger rockets. Made of extruded aluminum, the extra mass and shape of the rail makes for a much stiffer guide, which ensures that the rocket stays vertical as it launches. Instead of lugs, ‘rail buttons’ are used, which slide into the channel of the rail to provide the guidance. There's a picture of a typical rail in the extended entry.

A launch tower is primarily used in altitude contest launches. Instead of a lug or buttons attached to the rocket, the tower provides the guidance for a rocket by using three rods or rails spaced around the rocket body (between the fins). In its simplest form, a launch tower can be three parallel rods sticking up out of a coffee can full of cement. The main advantage is that since the rocket doesn’t have lugs or buttons, there is significantly less drag, which makes for higher altitudes. The main disadvantage is that a tower is only good for one diameter of rocket, unless some way of adjusting the guide rods is included, which adds to the complexity and cost. This elegant design here – by another Ted – allows for the three most common diameters of model rockets.

A launch tube is similar to the tower, except that the guidance is provided by the walls of the tube against the tips of the fins. Unlike a gun barrel, there is no back pressure assisting the liftoff. There are ways to use the ‘cannon’ method of launching as well, but it’s difficult enough that it’s not usually worth the effort and extremely rare to see it done.

Professional rockets use a variety of these methods, usually for the same reasons we do. The Super Loki Dart sounding rocket (this picture is of a scale model) is launched from an 12Â’ long tower (picture here along with some specs) that is spiraled like a gun barrel to provide spin and extra stability. The Loki reaches Mach 5 in a little less than a second, so staying straight is critical or the rocket will break into pieces.

Personally, I use launch rods up to about ¼” diameter – on anything up to about 2 pound rockets. I have rail buttons mounted on our larger rockets, and a lot of our rockets are rigged to use either, just in case a rail isn’t available. Given a choice, I’ll use the rail any time, because I’ve seen some scary flights caused by rod whip. more...

Posted by: Ted at 03:16 PM | category: Rocketry
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1 Thanks, Ted. I found it fascinating!

Posted by: Victor at December 22, 2003 04:21 PM (L3qPK)

2 Good primer! So I'm thinking rod whip with a bowling ball could be disastrous.

Posted by: Velociman at December 22, 2003 05:50 PM (iT+bD)

3 first time i visited wallops island and saw the launch sites, i was mighty pleased to see how similar to model rocket launchers they are. i was surprised to learn that for some vehicles they just stack the stages and don't even bolt 'em together.

Posted by: chris hall at December 22, 2003 05:57 PM (/wAa8)

4 who knew?? thanks Ted

Posted by: jim at December 22, 2003 11:13 PM (lN8eP)

5 I'm not sure rod whip plus bowling ball exactly equals disastrous. I'm thinking bowling ball flying all over the fucking place equals disastrous.

Humorous, kinda, but disastrous.

(I just wanted to type, "bowling ball flying all over the fucking place," in case you were wondering. I think that should be your new tagline, Ted.)

Posted by: Victor at December 23, 2003 09:27 AM (L3qPK)

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From the Rec.Models.Rockets newsgroup (my notes and clarifications are in italics):

Arizona High Power Rocketry Association (AHPRA) will be once again holding the bowling ball loft at LDRS (annual high power rocket launch featured in the Discovery Channel programs).

For LDRS 23 the Bowling Ball Loft class will be I-Lite (on the small end of the scale for 'I' sized motors). This was chosen to best suit the field size and waiver restrictions at the New York site (yes, safety matters to us).

Rockets will be launched for maximum altitude with a payload of one eight
pound bowling ball using an I motor from the approved list.

In addition to the regular cornucopia of prizes AHPRA gets from vendors
there is the potential to win up to $1000 (One Thousand Dollars US) cash if
you set the new I Lite record during the contest.

Look here for more information.

Posted by: Ted at 10:49 AM | category: Rocketry
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In the extended entry is a picture of me holding my semi-scale model of a Phoenix air-to-air missile.

I won this kit in an online raffle, and she flies great on 'H' motors. She'll handle 'I' and 'J' motors as well, but I haven't tried them yet. Thanks to all the fins, once the motor stops burning and she's coasting upwards, you can hear her whistling. It sounds pretty cool. more...

Posted by: Ted at 09:47 AM | category: Rocketry
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1 You sure do look a lot like my older brother.

Posted by: Rocket Man at December 16, 2003 11:00 AM (kZVsz)

2 Exhibit A in BATF vs Ted

Posted by: Victor at December 16, 2003 11:47 AM (L3qPK)

3 Hello Charlie Daniels!!

::looks around::

hey where's your wish list ?

Posted by: jim at December 16, 2003 01:01 PM (RCjGK)

4 Hello Charlie Daniels!!

::looks around::

hey where's your Amazon wish list, it is the Christmas season ya know.

Posted by: jim at December 16, 2003 01:03 PM (RCjGK)

5 Thanks for the compliments (and not turning state's evidence, Victor). My wife was horrified when she saw my Amazon wish list, you folks would stop speaking to me.

Posted by: Ted at December 16, 2003 02:18 PM (blNMI)

6 I love a man with a big rocket.

Posted by: Dawn at December 19, 2003 12:18 AM (0zfIx)

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