Sunday, February 28, 2010

Pro24 at NARCON

Rumor is, Cesaroni will be debuting their Pro24 line at NARCON. I'm not 100% sure about having a ride to Worchester, but I really hope to go as it looks to be a lot of fun.

Fliskits has models of two of Dr. Robert Goddard's rockets available; a BT-55 (1.33") version of his L-13 rocket, and a fairly large model of his first liquid-fueled rocket, 'Nell':

(Image from Rocketry Planet)

Saturday, February 27, 2010


Once again, I've decided to do something stupid because I can, and it might be interesting. I'm going to read one new book every single day from now till when my giant pile of books is exhausted.

I started today. I've already finished Soul of a New Machine by Tracy Kidder, which is a very interesting account of the creation of one of the first 32-bit minicomputers at Data General in the mid 1980s.

Friday, February 26, 2010

Rocket Team Vatsaas

Thanks to Dick Stafford, I have discovered the Rocket Team Vastaas webpage. And wasted half my afternoon on it.

They've got a lot of cool rockets, including Evil Berts, large scale models (inlcuding large SS1s and a 42% scale Standard Missile), and really fat, bulbous rockets that shouldn't be stable, but are.

They also have a list of peculiar rocket names, stating that "generally, a rocket name falls under the category of 'peculiar' when it indicates the author may be hiding a socially abhorrent personality disorder".

Thursday, February 25, 2010

Aerotech 29mm Spacer System - A Preview

Aerotech has a preview of their 29mm spacer system up on their Facebook page.

It's expected to cost $29.99 and will be fully compatible with Aerotech-branded cases as well as licensed Rouse-Tech and Dr. Rockets casings.

It includes a forward retainer ring, floating forward closure, and two 1-grain spacers:

(clicking on photos takes you to the photo in their album on Facebook)

Here's what the retainer ring and floating closure look like installed in a 29mm case, with no spacers:

No word yet on whether there'll be a special spacer for 29/100 loads. The adapter system is due out in April.

Aerotech is also planning a '38mm Special' with their 38mm system. 38/360 case, aft closure, retaining ring, floating forward closure, and two 38mm spacers, all for just $59.99. That's the ability to fly all 1, 2, and 3-grain (120, 240, 360 Ns) Aerotech 38mm loads, for 25 bucks less than the cost of the 38/360 system alone. I'm in.

Solar System Simulator

R2K points out this wicked cool planetary simulator. It can accomodate up to four bodies in a single plane. There's a lot of cool stuff you can do with it, including simulating multiple stars. I've created some really neat systems, including one system with two earths orbiting in opposite directions where their orbits continually changed and changed each other, but neither had the gravitational influence to send the other out of the system or into the sun.

The University of Colorado site has a bunch of awesome simulations in physics, chemistry, biology, electronics, earth science, and more.

Wednesday, February 24, 2010

20 years

Today would have been Lauren Candler's 20th birthday. Rest in Peace, Lauren.

Wikipedia and xkcd

How awesome is xkcd? Enough that Wikipedia has a page on whether or not xkcd belongs in the 'in popular culture' section of a page.

Tuesday, February 23, 2010

Sudden Mach fins

Now that I've figured out what to call it, and I've got the general design down, I'm trying to figure out what to use for fins, because that's pretty much the only work on it I can do till I aquire the nose cone, kevlar shock cord, rail buttons, and av-bay parts.

They'll be pretty standard swept trapezoidal fins. I haven't decided on the exact dimensions yet, but it'll have 3 fins, roughly 7" long and 2.5" wide, shaped like this:

The question is the material. I will likely use 1/8" plywood. It's light and strong, and I have plenty available. The problem is that I'm not quite sure if it is strong enough for speeds approaching Mach 1.8 (~ 600 mps, or ~1340 mph).

Balsa is right out because it would shred nearly instantly. Basswood is a possibility, but it's prolly very similar to my plywood in properties. Carbon fiber, used in the Wildman Blackhawk, is superstrong but heavy, which would mean giant draggy fins just like on the Blackhawk. Plus, carbon fiber is ridiculously expensive.

So, if I do need stronger fins, I have three options.

First, I could buy really nice 5/32" or 3/16" plywood, which is nice and strong, and better quality than my plywood. The problem is that that creates a lot of weight aft, which requires bigger fins or nose weight. Weight is not as much an issue with the Sudden Mach as with other, smaller Machbusters, but I need to keep the loaded weight below 12 ounces to directly compete with the Blackhawk, and below 10 to really out-accelerate it.

Second, I could buy custom-cut G10 fins. There's several small companies that do such work. I could have them perfectly cut and shaped, edges rounded, and very professionally smooth for a not-ridiculous amount. There's only two problems with that. First, Fiberglass is three times the density of birch ply (1.85 grams per cubic centimeter, versus 0.63). That means bigger fins, or nose weight. They're also against my self-imposed rules of no phenolic, Blue Tube, fiberglass, carbon, or metal. I intend to beat the Blackhawk with nothing but cardboard tubing, plastic, and wood.

Third, I could get aluminium fins. Incredibly thin, incredibly strong, and absolutely unshreddable. But again, they're not conventional fin materials, they're heavy, and getting them fabricated could cost me a pretty penny.

Monday, February 22, 2010

Priming and painting

For the first time in over a month, the weather got over 50° more than momentarily today. 50 is a pretty important temperature because that's the minimum temperature for my auto primer. So, I went out and painted some rockets.

First, I primed everything:

Viper IV (fin unit only)
18mm booster (still needs a name)
18mm glider pod (ditto)

The can of primer was almost 7 bucks but well worth it. It coated everything nice and smoothly and dried very quickly. I let it dry for about 20 minutes before I came back to paint.

I'm not sure how I'll paint the Viper IV yet, so I didn't paint the fin unit.

The Svetlana got a coat of a nice cherry red. Sometime later I'll add black fading a patterns, per suggestion of mandachan.

The SpaceShipOne is now white, although it'll need a second coat for full coverage. Already, though, it looks so much better than before. Putting primer on, especially the nice auto primer, makes the bottom coat opaque so the paint really looks nice and even.

The 18mm booster is now yellow; I might add a roll pattern later. Feel free to suggest names for it and the glider boost pod in the comments.

I painted the boost pod yellow on one side, green on the other. Green is usually a dangerous choise cause it blends in with grass, but the yellow will make it easy to find.

Pictures will come later, maybe tomorrow, after everything is dry and I can bring them all inside without stinking the house up.

More pictures!

First, my 24mm motor cases, because I never got around to gettign a picture of the 24/60 case. Its primary differences from the 24/40 case - length, and bigger aft closure - are pretty readily apparent. The orange thing is a really nice flet sleeve my mom made me.

Next is my new 18mm booster stage, with Wizard for size comparison. Huge fins = very stable.

This my new 18mm boost pod for gliders. They're hard to see, but it's got both a 1/8" and a 3/16" launch lug. One attaches the rocket to the launch rod; the other holds the glider. The little fins are for extra stability. I've had a few gliders break free prematurely before; the fins will keep the pod stable until ejection rather that having it go unstable and possibly crash.

And finally, the SpaceShipOne, stripped of much of its paint and sanded down, ready for primer. It's going to look so much better after it's repainted, because i really botched up the paint job before.
Posted by Picasa

Sunday, February 21, 2010

Dual Deployment

So I've been doing some more designing lately on the Sudden Mach, which is my 29mm Machbuster design, which I have designed to drag race the Wildman Blackhawk*. I don't have a final design yet, but after running a few basic simulations I have come to the unremarkable and inescapable conclusion that it's going to go very high.

On the order of 800 feet on a D, 1800 on an E, 2300 on an F, 3500 on a G, up to 4500 on an H motor, and as high as 6500 feet on an I motor. 6500 feet is one and a quarter miles. 2 kilometers. If I launched it from sea level, it would top out at roughly the same elevation as Mount Washington. Only about 2200 times faster than me climbing it.

At those altitudes, it'll be next to impossible to recover it. Even with a 3:1 ratio of drift to fall, as would be for a 12" parachute, it'll end up nearly half a mile away, more if it's windy. An 18" chute, better to avoid damage, would make the chance of getting my casing back very low.

So, I've decided to go the dual-deploy route. It's tricky, because you have to coordinate multiple reocvery devices, but it'll be worth it. The way it works is that you separate the rocket into two parts - the nose section which contains the primary parachute, and the fin can (with motor) that contains a streamer or smaller chute. In between, usually inside a coupler, goes an avionics bay (av-bay) with a dual-deployment altimeter.

You program it to deploy the streamer at apogee, and the main chute at a lower altitude; it does so by firing blackpowder charges. From apogee to the lower alittude (500-1000 ft), it falls quickly but controlled. After the main deploys, it falls slowly, but with less total drift than main deployment at high altitude. The system lets you land more easily in smaller fields, with less drift.

Saturday, February 20, 2010


I got to go skiing today at Stratton Mountain in Vermont. It was only my second time skiing at a large resort, and it was great. It was a bit crowded a few times, and the snow was a bit choppy, but I got 18 runs in.

I went down a double black diamond trail for the first time, and amazingly did not kill myself in doing so. In fact, despite snow that contained both thick powder and icy spots, I did not fall even once. There were a handful of times where I hit an icy patch and went too fast on a steep trail, and twice I felt fully out of control, but I was always able to recover.

Ironicially, we only went on Stratton's best lift - the gondola - once. It's enclosed, warm, and fast, but the lines are long, and we preferred to stay on the harder trails near the peak. So, after the initial ascent, we skiied down two-thirds of the way to the fast 6-person chairlift, rode it to the top, and repeated.

My dad commented that it was like two different mountains on the same day. There was nearly constant cloud cover over the peak, with fog and high winds. The trees were covered in snow, and the trails were steep and icy. Nearer the bottom, the skies were clear, the winds calm, and the trails flatter and with more powder.

I drove from the Vermont border to Stratton, and from Hartford to home.

Friday, February 19, 2010

Bill Gordon

Via every major newpaper on the planet comes the sad news that Bill Gordon, designer of the massive Arecibo radio telescope, died at 92.

Gordon was born in Paterson, NJ in 1907. He earned his master's degree from NYU and his doctorate from Cornell, where he taught from 1953 to 1966. He later taught at Rice University from 1966 to 1985.

He was one of the major designers of Arecibo in the 1950s; he later said, "We were in the position of trying to do something that was impossible, and it took a lot of guts and we were young enough that we didn't know we couldn't do it".

Since its opening in 1963, Arecibo has been used for all kinds of research, including determining Mercury's rotation period, discovering numerous pulsars, proving the existance of neutron stars, imaging asteroids, observing planetary features, and radio spectroscopy.

It was also used during the cold war to locate Soviet radar stations by observing their signals.... BOUNCED OFF THE MOON.

It also notably appeared in Goldeneye.

Thursday, February 18, 2010

Mach Goon might actually fly

I just noticed yesterday that Apogee Components now carry Cesaroni ProX motors. They only have the Pro29 and Pro38 motors, and no reloads, but that's okay.

I have a 25-dollar gift certificate to Apogee, which will buy me a 1-grain 38mm case. With a G115WT or G185VM load bought at NERRF, that'll put the Mach Goon supersonic, and even if I never find it, it's still under 50 bucks for a supersonic flight.

Wednesday, February 17, 2010

This is taking forever

Currently, the Viper IV construction is almost so very nearly at a halt. I've got the entire fin assembly glued together, so now all I have to do is the fillets on the fins. Which, due to the four motor tubes intersecting, have any number of little nooks and crannies that are really really hard to fill. In fact, there's a total of 56 inches of fillets that I have to rid off some 40 tiny little holes, and I can only work on one of the four sides at a time.

Which effectively means that this is going to take a while. Sunday is about the earliest I can possibly expect to be done with the fillets. Fortunately, after that, it's smooth sailing - just glue on the fin unit, tack down the launch lug, and tie the nose cone to the shock cord.

And, of course, 2 coats of primer and 2-4 coats of paint, but that's another story.

However, I do have some side projects going. The first of those I started today. It's a new 18mm booster stage, to replace the older version that got destroyed in spectacular fashion. While this one still won't be able to survive a 300 feet-per-second power prang**, it does have some improvements.

It's a brand-new piece of tubing, rather than a crappy piece of scrap. The tubing is a bit long so that the butt joint between the upper-stage and lower-stage motors is inside the tubing, which lessens the likelyhood of the joint bending. The fins are large, strong 3/32" balsa and will have double fillets of wood glue, so they'll be very strong. They're nice and large, which will keep the rocket stable and also slow the booster down on its descent.

I've also got a few other designs that I'll be building soon. They include a 13mm boost pod for gliders, a 29mm saucer, and a ridiculously complicated design.

Tuesday, February 16, 2010

No time

Sorry, folks. I have no time to blog tonight because I have to finish an English essay that I procrastined on. More stuff comes tomorrow.

Monday, February 15, 2010

Viper IV part VI: Pictures!

Because I know I've only got about one more post before someone bugs me for pictures...

This first one is the fin unit with the fillets drying. It's up on blocks so it stays upright.
Note the way the 4 motor tubes fit into the brown coupler; it took a lot of balsa, tissue paper, and wood filler for the nice joint you see here. Also note the 4 motors test-fit into the motor tubes, and my homemade motor retainer.

When I'm old and stodgy and have a desk and an office, I will make one of these fin units again. Because it's so much cooler than a plant, serves as an auxilary paperweight, and start a lot of conversations. Especially if everything goes as planned and I go into aerospace engineering.

This is just a dry fit, but it's roughly what I'll look like glued together. except for the whole 'paint' thing, of course.

Here's a close-up of the shock cord mount.

I bought some extra 1/4" elastic today. I'm going to add 9 feet of that to the 8 feet of shock cord already included with the Viper IV. More shock cord means less change of it breaking or of the nose cone bouncing back and hitting (and damaging) the body, and makes it 9 feet easier to recover if it lands in a tree.

Posted by Picasa

Sunday, February 14, 2010

Bloody Valentine's Day

Valentine's Day is known for smarmy Hallmark cards, candy, and red. Not just the sweet, saccharine red. There's also the sanguine bloody red. Turns out, there's been a lot of blood shed on February 14th:

It all started back in 250 CE (or 269, or 270, or 273...) when Saint Valentine got himself martyred. Turns out no one knows who he was, when he lived, or exactly what he did to get himself killed, but the Eastern Orthodox Church made him a saint nontheless. In 496 CE, Pope Gelasius I decided that a day for lovers should totally be on the day of some punk who got himself killed in some spectacular fashion. Then, in the 15th century, some punk named Chaucer decided it should be all about romantic love. Yeah, screw you, Chaucer. Your very special day got Hallmarked.

Folk waited for a while, and then they got bored again, and bored people love going on murderous rampages. So, in 1349, in Strasbourg, Germany, in what saner folk named the Strasbourg pogrom, over 300 Jews were killed and thousands of others expelled for really no reason.

The nastiness then shifted to the beautiful islands of Hawaii where in 1779 the explorer extraordinaire James Cook got himself killed by the natives. Possibly for trying to kidnap their king which, in retrospect, is never a good idea. Ever.

After that, the bloodiness got more and more frequent, at least what was recorded. In 1797 323 sailors were killed and some 880 wounded in the Battle of Cape St. Vincent. In 1804, the First Serbian Uprising began, setting off 13 years of nastiness between the Serbs and the Ottoman Empire. In 1831, there were "immense casualties" at the Battle of Debre Abbay in Ethiopia.

(Sense a theme here...?)

In 1879, Chile touched off the War of the Pacific, in which over 21,000 poeple were killed and as many wounded fighting over a rainless desert filled with saltpeter and... bird shit. In 1920, the CCCP started the Polish-Soviet war, which ended 3 years later, with no clear victor, after taking somewhere between 150,000 and 250,000 lives.

In 1929 came perhaps the most infamous of all these events: the St. Valentine's Day Massacre. Seven men, five belonging to Bugs Moran's North Side gang, were killed by the tommy-guns of four still-unidentified members of Al Capone's South Side gang.

World War II brought attrocities of a scale never seen before or since; one of those was the firebombing of Dresden which began on February 14th, 1945, and was not the Allies' finest moment. Happy Valentine's Day, Dresden. Because your city is still a center of industry, we're going to drop 7000 tons of phorphorus bombs on it, turning 90% of the city into a raging firestorm that kills 25,000 people. About 2% of the bomb force got off course and managed to drop bombs on Prague 100km away from their target.

There's been a number of assassinations and murders on this day. Finnish progressive politician Heikki Ritavuori was murdered in 1922, an event that shocked the nation. In 1979, American ambassador to Afghanistan Adolph Dubs was killed during a kidnapping attempt. In 1989 the Ayatollah Khomeini issued a fatwa against Salman Rushdie for writing The Satanic Verses, which resulted in the deaths of at least 38 people. Because clearly, a blasphemous book is worth killing dozens of people, mostly innocents killed in a bombing, over. In 2004 and 2005, terrorist bombings killed 22 and 7, respectively, in Lebanon and the Phillipines. In 2008, six were killed in the NIU shooting.

Not all the blood on Valentine's day is intentional, though. In 1981, 48 died in the Stardust disaster when the eponymous nightclub caught on fire and, once again, idiotic managers had chained fire exits closed. Indian Airlines Flight 608 crashed on February 14, 1990. In 1996, a Chinese Long March launch vehicle carrying Intelsat 708 went off course and crashed into a village, killing 6 (according to the Chinese government) and possibly as many as 500. Finally, in 2004, the Russian Transvaal water park collapsed, killing 28.

However, if you're reading this, you've survived another Valentine's Day, and it's a dangerous day.

Saturday, February 13, 2010

Viper IV building part V

Over the last few days, I've actually managed to get the fins on the Viper IV.

Since it's been pretty wet and humid the last few days, I knew that trying to glue each fin on with wood glue would not work, because it would take forever to dry and the bond wouldn't be that great. Instead, I spread superglue along the joint between the fins and motor tubes, forming an instant bond that holds the fin in place. Then, I used wood glue to make a fillet. They're still finishing drying and will require a second coat, but once finished all four fins will be strongly attached to the motor tubes with smooth joints.

The way that the Viper IV is built is somewhat unusual. For most mid-power rockets, one glues the motor mount inside, then attaches the fins either directly to the body tube, or through it. Every major component is glued to the body tube, which is the foundation of the rocket. With the Viper IV, the foundation is the quad motor mount. It takes a lot of work to glue the motor tubes together, add positive retention, fit the motor mount into the coupler, and glue on the fins. Only at the end is the whole subassembly added to the body tube, and the only other things glued to the body tube are the shock cord and launch lug.

Friday, February 12, 2010


I've been watching the opening ceremony for the Olympics for the last three hours and it's just stunning. Incredible coordination with thousands of people and mechanical devices and the effect is just stunning.

I was especially impressed with the girl who sang the Canadian national anthem at the beginning. She's just 16 - the same as me, and she sang literally for the world. She sang a difficult song perfectly, and didn't even look nervous. She even looked like she was smiling. As someone who had to work up the courage to appear onstage for 30 seconds in a school play and gets the shakes playing in jazz band, I am in awe of her calm.

Thursday, February 11, 2010

The uses of Lutetium

Although it's virtually unknown, and spectacularly rare (0.00005% by weight of the earth's crust), lutetium is produced in small commercial quantities, and does have its uses.

Lutetium is primarily extracted from the mineral monazite, which contains 0.003% (30 parts per million (ppm)). The chemical process is rather complicated and produces lutetium oxide. Only about 10 tons are produced annually.

The pure metal itself has only recently been extracted and costs about $10,000 (USD) per kilogram, or about 1/3 the price of gold. It's created by reducing a lutetium halide with an alkali or alkali earth metal; for example: 2LuCl3 + 3Ca → 2Lu + 3CaCl2

Most of the uses of lutetium are above my level of understanding, but I'll try to explain them.

  • The radioisotope 176Lu is used to date meteorites
  • The radioisotope 177Lu is sued as a beta emitter for treatment of certain tumors in the neuroendocrine system
  • Cerium-doped lutetium oxyorthosilicate (LSO), which has the chemical formula Lu2SiO5, is the preferred detector material for PET scanners
  • Pure lutetium can also be a catalyst for various organic reactions including petrochemical cracked, polymerization, hydrogenation, and alkyzation

Tomorrow: part 3: Lutetium compounds

Wednesday, February 10, 2010


There are 118 elements on the periodic table. Many are well-known - everyone knows to iron, copper, tin, and oxygen. Others are somewhat more obscure, but most folks have still heard of barium, tungsten, or thallium. However, there are a few truly obscure ones. For example, no one knows lutetium.

Perhaps that's because it's not used for... well, much of anything, really. Or that it's ridiculously rare. And it's almost impossible to isolate. That doesn't mean, though, that it's not still pretty cool and worthy of attention.

Lutetium is element #71, with 71 protons, and has 104 neutrons in its single stable isotope, 175Lu, which makes up 97.41% of all naturally made lutetium. However, the isotope 176Lu, with 105 neutrons, has a half-life of 37.8 billion years, makes up 2.59% of natural lutetium. There are also 32 other radioisotopes of lutetium, with atomic masses ranging from 150 (79 neutrons) to 184 (113 neutrons) and half-lives from 150 nanoseconds to 3.31 years, or 37.8 billion years in the case of 176Lu.

Lutetium was discovered in 1907 by Georges Urbain; it was one of the last of the non-radioactive elements to be discovered. He as the discoverer suggested 'lutecium' (from the Latin Lutetia meaning Paris [the city of light]) which was changed to lutetium for standardization in 1949.

Coming tomorrow: lutetium uses!

Tuesday, February 9, 2010

Wikiconnecting, or, 10 degrees of relation

The challenge: pick any two random Wikipedia articles. Then, try to get from one to the other in ten clicks of less.

Easy: you pick two random articles that don't seem related
Hard: pick the two articles with the 'random article' button
Adult variant: end with the 'Human sexual intercourse' page

A few examples:

Easy (4 clicks):
pencil to Mt. Hood
1: Juniperus virginiana
2: Missouri
3: Oregon
4: Mount Hood (finish)

Hard (7 clicks)
Geoff Southby (random article), going to Neufchâtel-sur-Aisne (second random article)
1: Australian rules football
2:World War I
3: Harbonnières
4: Picardy (region)
5: Aisne
6: Cantons of the Aisne department
7: Canton of Neufchâtel-sur-Aisne (finish)

Frequently, a game will start out with a few clicks between seemingly unrelated subjects to get closer to the subject matter. For example, Pencil jumps to the red cedar tree, which gives states as geographic markers. From there it's simply a jump to oregon, then Mount Hood.

The 'hard' example is actually more formulaic, and works well with organized subjects like towns and athletes. I went immediately to the broadest category - Aussie rules football - which under the history section linked to WWI. There I clicked on the location nearest my target, then just went up and down administrative divisions to the target.

I conjecture that any pair of Wikipedia articles can be connected by no more than a dozen clicks due to the sheer number of internal links.

Go ahead, waste 10 minutes and try playing.

Viper IV building part IV

I've finally managed to get the motor mount almost complete. It took quite a bit of balsa to get the 4-tube cluster to fit exactly inside the 2.56" coupler, but that turned out to be the hardest part.

After that, I just stuffed tissue paper down into the cracks and covered that with wood glue, creating a hard stuffing that won't let ejection charge gasses leak past. Finally, I covered the end with wood filler for smoothness, and that's currently drying. Pictures will come, eventually.

Hopefully, I'll get a lot done tomorrow. We're supposed to get up to a foot of snow, and school got canceled at 8:40 pm. That's only the second time in the last decade that it's gotten closed the night before, and as I write this just before midnight it hasn't even started snowing yet!

Monday, February 8, 2010

The MIA chute

One year ago yesterday, the SpaceShipOne landed in a fine tall oak tree after drifting too far under its 24" chute. Five days later, the body of the rocket fell back down, undamaged. Two weeks later, the nose cone followed.

However, the orange parachute stayed. And stayed.

Finally, last week, the wind blew it away. After over 350 days in the tree.

Sunday, February 7, 2010

History Day!

It's been over a year since I did a proper History Day post. Which means it's time for the tradition to start again...

1804: John Deere - yes, *that* John Deere - was born.

1812: The strongest (Magnitude 8.3) of the New Madrid earthquakes destroyed the town of New Madrid, toppled buildings in St. Louis, made waterfalls on the Mississippi and changed it course, caused a wave to run UPSTREAM on the Mississippi, and rang church bells all the way to Boston.

Also 1812: Charles Dickens, great and intolerably boring Victorian writer, was born.

1867: Pinoneering pioneer writer Laura Ingalls Wilder was born.

1889: Harry Nyquist, a founding informational theorist, was born.

1906: Oleg Antonov, Soviet aerospace engineer, designer of planes from small biplanes to the monster An-225, and the founder of the eponymous Antonov design firm; was born.

1926: Konstantin Feoktistov, cosmonaut and spacecraft designer, was born.

1932: Apollo 15 command module pilot Al Worden was born.

1935: Monopoly is invented. Rainy Sunday afternoons become a little less boring.

1959: Baseballer extraordinaire Nap Lajoie died at 84.

1960: Igor Kurchatov, father of the Soviet atomic bomb but also an advocate of peaceful nuclear power, died at 57.

1979: For the first time since Pluto's 1930 discovery, its orbit brought it closer to the sun than Neptune.

1984: On the Shuttle mission STS-41B, astronauts Bruce McCandless and Robert L. Stewart performed the first untethered spacewalks using the MMU.

1990: The Soviet Union ended when the Central Committee of the Soviet Communist Party relinquished its power.

1999: King Hussein of Jordan, a skilled diplomat, peacemaker, democratic and civil rights activist, ameteur radio operator, pilot, and all-around awesome guy; died at age 63 after having ruled Jordan since age 17.

2010: A large explosion at a power plant in Middletown, CT - near where I live - killed at least 5 workers.

All information except the last item from Wikipedia.

Saturday, February 6, 2010

Marie Curie Quotes

Not only was Marie Sklodowska-Curie an incredible scientist and quite possibly the single person who ended science being a misogynistic 'old boy's club', but she also said a number of very profound things:

  • "Be less curious about people and more curious about ideas."
  • "You cannot hope to build a better world without improving the individuals. To that end each of us must work for his own improvement, and at the same time share a general responsibility for all humanity, our particular duty being to aid those to whom we think we can be most useful."
  • A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale. We should not allow it to be believed that all scientific progress can be reduced to mechanisms, machines, gearings, even though such machinery also has its beauty. Neither do I believe that the spirit of adventure runs any risk of disappearing in our world. If I see anything vital around me, it is precisely that spirit of adventure, which seems indestructible and is akin to curiosity."
  • "Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less."
  • "I am one of those who think like Nobel, that humanity will draw more good than evil from new discoveries."
  • "And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity."
  • "One never notices what has been done; one can only see what remains to be done.

"I am among those who think that science has great beauty."

Friday, February 5, 2010

Contacting me

I've added a new page with blogger, to list my email addresses. It's here, and I'll improve it eventually. I might also add pages for listing stuff like the blogs I follow, or my most informative posts.

Viper building part III

I've got some more building done over the last few days, mostly using my wonderful epoxy clay.

First I installed the shock cord mount. It's an 18" length of 1/8" nylon cord. The instructions say to tape the ends to the inside of the body tube about 4" down from the forward end and slather with epoxy. I used epoxy clay instead, but it's still very strong.

Second is the cluster mount assembly. I epoxyied two nuts between the four 24mm tubes, and used a threaded rod to get them an exact distance apart. I also epoxied a washer to a 2" length of threaded rod. Now, all I have to do to retain all four motors is to thread the rod-with-washer into the middle of the cluster and the washer holds all four motors.

Thursday, February 4, 2010

New Quest D motors certified

Comments in bold are mine. 4.45N = 1 pound

R133: NAR S&T New Motor Certifications:

24mm x 70mm
18.59Ns total impulse
28.88N peak thrust
8.44N average thrust
22g propellant mass

This is basically a lower-thrust D12. Same size, same delays, and just a hair more impulse. The 29N spike, though, should be enough to get decent-sized rockets off the pad.

20mm x 96mm
17.61Ns total impulse
16.80N peak thrust
3.82N average thrust
24.0g propellant mass

This is an interesting development. It's their D5 motor, originally designed for rocket gliders, but with delays and an ejection charge. It's got decent oompf - 16.8N (3.78 lbs) for liftoff - but it's otherwise a long-burning motor with low thrust. Good for gliders that need an ejection charge I suppose, but it doesn't fit in 18mm kits, is too low-thrust for most 24mm kits, and it's not useful for most contest rockets.

Wednesday, February 3, 2010

Long delays

I noticed on TRF today that Aerotech actually has three delays certified for the E20W: 4, 7, and 10 seconds. However, where they're for sale, I've only seen the -4 and -7 motors.

I've noticed this before with certain reloadable motors. There are often three delays listed on the packaging - short, medium, and long - but only the short and medium delays are certified and available. This includes most of their 24/40 loads plus a few others:



However, a number do have long delays available:
18mm: D13-10 and D24-10

24mm: F12-5*, F35-11


* The weird ones are the E11 and F12. Both are long-burn Black Jack motors. The E11-3 is widely available, but the listed E11-5 is not certified, and there's no true long delay at all. The F12-3 (certified as -2) and F12-5 are both available; however, once again no long burn time is listed at all.

Tuesday, February 2, 2010

Changes in the Rules

Recently, there's been some nastiness over having certified G sparky motors. It appeared to some that the NAR was trying to ban sparkies under 160Ns total impulse. It appears, though, that recommendations made by the NAR panel to the NFPA (National Fire Protection Agency) will likely become part of NFPA 1125 (Code for the Manufacture of High-Power Rocket Motors) in 2011.

First, they decided to raise the upper limit of propellant in 'model rocket' motor from 62.5g to 125g. This simply means that full G motors, like the Aerotech G75J, that are under the 80N average thrust limit but over 62.5g propellant are officially model rocket motors. A good thing, though technically all motors over 62.5g (and reloadables) cannot be sold to those under 18, though it's clear that no one really pushes the issue.

Second, model rocket motors are restricted to solid propellant. That means that the 3 hybrid motors (West Coast Hybrids G55 and Skyripper G63 and G69) out there that are under 160Ns and under 80N average thrust are now grouped as high-power motors, along with all the other hybrids.

Third, model rocket motors had their maximum particle size shifted from 150 microns (0.15mm / 0.006") to 74 microns (0.074mm / 0.003"). This puts most sparkies firmly in the HPR category; however, sparkies with impulses under 160Ns will still be allowed, and new ones can be certified.

Fourth, any motors under 160Ns (G size or smaller) that violate the particle size, solid-propellant, or 80N limits will be certified as high-power motors and have 'HP' added to their motor designation. This includes about 25 G motors which will have their designations changed.

Fifth, there were a few certification changes. Maximum motor casing temperature was increased from 200 C (392deg; F) to 220 C (428° F). Provisions will be made for testing motors with interchangable and user-set delay systems, and manufacturer designations must reflect average thrust to within 10N or 20%, whichever is greater. I'm not sure why these changes were needed, but they all make sense.

These changes are not official yet, but stand a high chance of becoming so. They seems to me to do a good job of clearing the issue and making everything fair.

Story from Rocketry Planet
Dick Stafford reports and comments

From the RP story: a great picture that speaks a thousand words. Gary Rosenfield (L) of Aerotech and Anthony Cesaroni of CTI at the meeting. Competitors in business, but partners in making the rules good.

Monday, February 1, 2010

No time

The EGE has a 3-page paper due tomorrow monrning. Hence, nothing to say, sorry.