Successful Aerospike Test

Here's a good explanation of what aerospike rocket motors are all about.

There are pictures here, and if you select the medium or large sizes, you can really study the detail of the aerospike design (if that sort of thing floats your boat).

The names and organizations involved are familiar to rocketeers, because this is the kind of cutting-edge experimentation that some of us get involved with. Here's the inside scoop from Chuck Rogers, one of the people involved, as posted on the Rec.Models.Rockets newsgroup (links added):

Cesaroni Technology Incorporated did a great job on the structural design and fabrication of the aerospike. The aerospike retrofits onto an O5100 motor in place of the conventional conical nozzle. BlackSky Research built the Optimal 168 rocket, and ran the launch operations for the flights.

I've seen the Cessaroni motors flown, and they are sweet. They're also commonly available to people like myself who fly the smaller rockets. BlackSky is another company that does everything from hobby rocketry to 'real' experimental rocketry. My launch rail was made by them.

The aerospike is a centered Prandtl-Meyer all-external expansion design. It delivered 97% of ideal efficiency in ground test (exceeding historical Rocketdyne data), and theoretically would deliver the same high efficiency from sea level to vacuum flight conditions.

Even the most optimized conventional nozzles are compromises for the expected range of altitudes and pressures expected. The efficiency of the aerospike means that bigger payloads can be lifted on a given thrust.

The rocket flights were to demonstrate operation of the aerospike in flight, and to measure installation effects compared to the uninstalled ground static firings. CFD was run not only for the aerospike hot gas flowfield, but for the combined rocket and aerospike plume flowfield.

This is the most highly instrumented high power/experimental rocket ever flown. In addition to highly accurate accelerometers and pitch, yaw, and roll rate sensors, the rocket used a conic nosecone with a built-in Flush Air Data System (FADS) (like a pitot tube), calibrated with CFD and cone pressure tables. This was the first inflight direct aerodynamic measurement of angle of attack on a model, high power, or experimental/amateur rocket.

Blacksky Research coordinated the development of the aerospike nozzles and solid rocket motors, provided overall project management on the contractor side, and really helped refine the whole concept of using large high power rockets for advanced flight test research. All at a low cost relative to normal government aerospace projects.

All that fun and saves Uncle Sam money too. Later on in the exchange, questions about the materials used to construct the aerospike were asked. This is why I love rocketeers, because Anthony Cessaroni himself jumped into the conversation:

Composites, ferrous and non-ferrous alloys, a little bit of graphite and a pinch of tungsten.

We also got to hear about one of the hazards of aerospikes (Chuck Rogers again):

Well, it turns out that the tungsten tip on the aerospike is REALLY SHARP. While walking around the rocket as it was mounted on the transfer cart I got "speared" by it. It put a tear in my shirt, but it didn't break the skin. It did not draw blood!

For this experiment we wanted a "pure" spike that went all the way to a sharp tip. For an "operational" aerospike there is predicted to be very little performance loss for up to a 25% reduction in the spike length.

You'd want at least some minimal truncation to avoid that VERY sharp tip.

Which was suggested by CTI, but again, for the "purity" of the experiment we wanted a sharp tip.

These are the kind of details that bring history to life. And to add a data point to our assertion that hobby rocketry leads to technology-related careers, here are two pages from a 1982 rocketry magazine written by "Crazy-Chuck" Rogers.

Posted by: Ted at 05:22 AM | category: SciTech
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Enough light to do the job

This redefines 'task-lighting', eh?

A U.S.-Israeli laser designed to protect northern Israel from missile attacks downed its largest rocket to date during a test over the southern New Mexico desert, the Army said Friday.

There's more coolness, you should check it out.

Posted by: Ted at 07:06 PM | category: SciTech
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.0001% less chance of nuclear winter

Note: my link for this has expired. Here's an alternate that still works, but it references the same dead link I had. In the meantime, here a quote from the original source:

"Thus, if the Minuteman III ICBMs have to be used in some future nuclear war, their rocket motors will not pollute the atmosphere. EPA regulations do not apply in foreign countries, so no changes are being made to reduce the harmful environmental effects of the nuclear warheads"

That's right folks, Uncle Sam's ICBM arsenal is now more environmentally friendly because their propulsion has been reworked in order to meet EPA regulations.

Update: The 'dead' link works again.

Posted by: Ted at 05:07 AM | category: SciTech
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Liquid Body Armor

Whoa.

Army scientists are working on a liquid body armor for clothing that stays flexible during normal use but can harden to stop a projectile when hit suddenly.

But like most innovation, the military application is only the beginning.

Wetzel and Wagner are optimistic the liquid body armor will be useful to local police and prison guards and perhaps it could one day protect people in automobile and airplane crashes.

Posted by: Ted at 04:54 PM | category: SciTech
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This reminds me, I need to mow the lawn

Buried in the jungles of Guatemala, excavations at Mayan ruins continue to surprise archeologists with unsuspected data.

A team of U.S. and Guatemalan archeologists says it has discovered important Mayan monuments covered with texts from the ceremonial ball court at the Cancuen palace in northern Guatemala.

Cancuen, one of the largest Mayan palaces found so far, was built between 765 and 790 A.D. by King Taj Chan Ahk. It is located along the banks of the Passion River, about 200 kilometers (120 miles) north of the Guatemalan capital.

They've been exploring those ruins for over 100 years.

Posted by: Ted at 01:05 AM | category: SciTech
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Like a kid on Christmas morning

A 1,000-ton barge rammed into a pier supporting an aging bridge over Florida's Apalachicola Bay last week, delighting civil engineers, who plan to ram it a dozen more times.

Depending on your job, it isn't often that you get real-life data to work with. These structural engineers are loving life right now, getting to study the effects of bridge and boat collisions. With the goal of improving national construction standards, of course. I watch NASCAR for the racing too.

When stationed in Germany as part of the US Air Force, I'd heard that the runways at Ramstein AB were going to be redone. Part of the plan was to let pilots blow hell out of things with live ordnance (great training), followed by Prime Beef teams repairing the runways afterwards (more great training). This was supposed to go on for some time as aircrews were rotated in for the chance to actually blow something up for real.

I transferred back to the States before that happened. Did it? If it did, I bet it was a great show.

Posted by: Ted at 02:26 PM | category: SciTech
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Mach 7

NASA's X-43A unmanned scramjet test vehicle made it's first successful flight today.

Back in January I posted about the ramjet powered Project Pluto, which included this link for a look at various types of ramjets and how they work.

Posted by: Ted at 09:32 PM | category: SciTech
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Tenuous Link

I have almost 20 years of experience working with the Model 204 Database Management System, aka M204. It's strengths are extreme flexibility coupled with excellent security features and blazing speed when working with massive databases. Here's a link to a recent press release about the product, and below an email I got:

Dear Model 204 User,

I wanted to draw your attention to a new press release posted on our Web site. Centrelink of Australia, one of the world's largest users of Model 204, has just signed an agreement with CCA allowing them to use Model 204 throughout their enterprise for at least the next ten years; that is at least until the year 2014. This is very exciting news not only to all of us here at CCA, but to the entire Model 204 customer base. It means that after 20 years of use at Centrelink, Model 204 continues to be the best product on the market to meet their ever-changing and ever-growing needs -- needs which are very likely similar to your own.

Centrelink originally chose Model 204 back in 1983 because it was the only product that could meet their performance and capacity requirements. Since that time their requirements have grown dramatically. What started out as a traditional database system with just a few thousand online users now services over 24,000 internal users and over 6 million customers over the Internet and Interactive Voice Response systems. They now run the fourth largest information and technology network in Australia and are still growing. With Model 204, they have been able to meet every new challenge, while integrating new technologies as they come to market.

This is the kind of application that would make Oracle do the 'dead bug'.

The tenuous link is that the company I work for had the original contract to optimize the Australian databases, way back in the 1980's. When I first hired on, I was hoping to be assigned to that contract.

Computer-wise, newer is not always better.

Posted by: Ted at 04:26 AM | category: SciTech
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Real hardware

Real Hardware. Photos and some historical background. Especially intriguing is the page about the ROTON. Alas, that company went bankrupt a while ago.

Posted by: Ted at 07:10 AM | category: SciTech
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Blizzard Rankings

The superstorm of 1993 was the most devastating blizzard to strike the Northeast in at least a century, according to a new system that rates the impact of East Coast winter storms.

Interesting, but rather limited. Since the 1-5 scale takes into account the population affected, it has to be derived from historical records. It's also only usable in current form for the Eastern Seaboard of the US, other regions will have to have their own custom formula developed.

I would like to see the correlation between IQ, size of the SUV, and bodyshop repair bills immediately following storms.

Northeastern winter storms rated "crippling" or higher on the new Northeast Snowfall Impact Scale.

Category 5: Extreme

1. March 12-14, 1993
2. Jan. 6-8, 1996

Category 4: Crippling

3. Feb. 15-18, 2003
4. March 11-14, 1888
5. Feb. 11-14, 1899
6. March 2-5, 1960
7. Feb. 10-12, 1983
8. Feb. 5-7, 1978
9. Feb. 2-5, 1961

So since I've moved into this area, I've experienced the top 3. Liz remembers 7 and 8, and my mother-in-law remembers 4 and 5 (just kidding!).

Posted by: Ted at 06:18 AM | category: SciTech
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Tiny Bubbles

Cavitation is the term for the formation and subsequent collapse of small bubbles in a liquid.

When a propeller spins in the water, the hydrodynamic forces may result in the creation of tiny bubbles. The bubbles are almost immediately crushed upon themselves which causes noise. The cavitation sounds are one method of detecting submarines on passive sonar. Great amounts of time and money are spent on refining propeller design to limit cavitation.

Cavitation can also damage propellers by pitting the metal over time. Naturally, this pitting further reduces the efficiency of the propeller while making it noisier at the same time. Scientists wondered what was actually happening during cavitation, and began to study the process in more detail.

What they discovered was that each bubble underwent an extremely violent death. As the bubbles collapsed upon themselves, the interior experienced supersonic shockwaves which reflected back from the bubble's outer surface. Happening in a fraction of a second, these shockwaves raised the interior temperature enough to rival the surface of the sun. It was these millions of microscopic sunbursts that were causing the pitting on the propellers.

The effect has also been exploited in various ways by weapons designers. One 'underwater' missile rides in it's own cocoon of cavitation bubbles, which form a barrier to the surface-drag caused by dense water, and allows the missile to 'fly' underwater at several times the speed of typical torpedos.

Now researchers are taking advantage of cavitation outside of naval affairs. According to this report regarding Bubble Fusion:

The research team used a standing ultrasonic wave to help form and then implode the cavitation bubbles of deuterated acetone vapor. The oscillating sound waves caused the bubbles to expand and then violently collapse, creating strong compression shock waves around and inside the bubbles. Moving at about the speed of sound, the internal shock waves impacted at the center of the bubbles causing very high compression and accompanying temperatures of about 100 million Kelvin.

These new data were taken with an upgraded instrumentation system that allowed data acquisition over a much longer time than was possible in the teamÂ’s previous bubble fusion experiments. According to the new data, the observed neutron emission was several orders of magnitude greater than background and had extremely high statistical accuracy. Tritium, which also is produced during the fusion reactions, was measured and the amount produced was found to be consistent with the observed neutron production rate.

Earlier test data, which were reported in Science (Vol. 295, March 2002), indicated that nuclear fusion had occurred, but these data were questioned because they were taken with less precise instrumentation.

Note that this was described as cavitation in a vapor. Most definitions I've seen specify liquid, although a vapor could be described as a low-density liquid.

Thanks to Fred for the Bubble Fusion link.

Posted by: Ted at 09:41 AM | category: SciTech
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Or you could wait 32 years

Five planets will be visible to the naked eye later this month. The next best chance to see this somewhat rare alignment is in 2036. Details here.

Thanks to J-Walk Blog for the pointer.

Posted by: Ted at 05:04 AM | category: SciTech
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Ig Nobel Prize

Awarded annually, according to the official site:

The winners have all done things that first make people LAUGH, then make them THINK.

Some of my favorites (go to the link above for full credits and cites):

Physics, 2003 - "An Analysis of the Forces Required to Drag Sheep over Various Surfaces."

This one's from Australia. Is anyone surprised? Montana residents put your hands down.

Biology, 2003 - for documenting the first scientifically recorded case of homosexual necrophilia in the mallard duck.

You really find out who your friends are.

Physics, 2002 - University of Munich, for demonstrating that beer froth obeys the mathematical Law of Exponential Decay.

More beer research, now this is something I can support.

Astrophysics, 2001 - a televangelist and staff, who for their discovery that black holes fulfill all the technical requirements to be the location of Hell.

So does Sunday morning television programming.

Peace, 2000 - The British Royal Navy, for ordering its sailors to stop using live cannon shells, and to instead just shout "Bang!"

As opposed to the more aggressive "Boom!"

Chemistry, 1999 - a detective in Japan, for his involvement with S-Check, an infidelity detection spray that wives can apply to their husbands' underwear.

The thrifty version is called superglue.

Peace, 1999 - a South African design for an automobile burglar alarm consisting of a detection circuit and a flamethrower.

I've barely scratched the surface here, go check 'em out. Science doesn't have to be boring, and stuff like this certainly makes me think... about committal papers.

Posted by: Ted at 04:50 AM | category: SciTech
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SQL

For our wonderful new work system, I'm having to learn more than the barest smattering of SQL I know. Any advice on some good books or website resources?

Posted by: Ted at 07:11 AM | category: SciTech
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Now to convince my wife that they're common and vulgar

Diamonds, that is. Terribly terribly not-precious anymore if these guys are right.

Thanks to Across the Atlantic for the pointer. Can you tell who the romantic is between the two of us?

Posted by: Ted at 07:18 AM | category: SciTech
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Electricity is smoke

As promised, here's another bit about the mysterious workings of technology. Once again, I found this on the newsgroup Rec.Models.Rockets.

I have found most electronic devices are powered by smoke contained in small black chips.

In fact, once the smoke is released from one of these black chips, the electronic device will stop working.

Next lesson: Gravity doesn't suck.

Posted by: Ted at 04:33 AM | category: SciTech
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Dark Suckers

From Michael M-B on the Rec.Models.Rockets newsgroup:

What is a Dark Sucker?

Many years ago Thomas Edison was experimenting with a method to remove the darkness from a room. By applying a electric current to a wire in a vacuum, he noticed the darkness in the room had vanished. Where had the darkness gone. He noticed around the wire a area of extreme Non-Darkness. He surmised that in fact, the wire had absorbed all the darkness from the room and concentrated it about the wire. When he removed the current from the wire the darkness returned to the room. Hence the invention of the Dark sucker!

Nowdays we have many types of dark suckers. Even portable Dark Suckers called flashed darksuckers, which remove the dark from a concentrated area a short distance away.

With every brilliant theory, there are those who disagree. In the world of Dark Suckers, these heretics believe that darksuckers are in fact not sucking the dark away but emitting photons (or light). Now all of us in the scientific world know this is falacy. The easy way to prove it to these heretics is the Sun.

The Sun's gravity in fact sucks all of the dark from surrounding space. Therefore making it not dark ( very bloody not dark in fact). And the dark is sucked so violently that heat is generated in place of the removed dark. Even Einstein knew this.

So next time you walk into a dark room and turn the switch watch how fast the Dark is Sucked from the room!

Next Lesson: Electricty is smoke.

Posted by: Ted at 09:26 PM | category: SciTech
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The red one and the yellow one refused to comment

Math Secrets of M&M's Revealed.

M&M sweets pack together more densely than perfect spheres when randomly jumbled in a container, scientists say.

Redefines the term "sugar orgy", eh?

Thanks to The Group Captain at Across the Atlantic for this.

Posted by: Ted at 08:23 PM | category: SciTech
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Amphibious Cars

At work my friend Kyle and I were in one of those wonderful conversations that hop from subject to subject, and eventually we got to talking about amphibious cars. Kudos to Kyle for finding that link.

Apparently, the idea is making a comeback. British company Gibbs is now offering the Aquada, which will do an impressive 100mph on land and 30mph in the water.

Or you can just go the do-it-yourselfer route.

Posted by: Ted at 10:25 AM | category: SciTech
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Happy Birthday

Gaston Julia

Google good. Fractals pretty. Math bad.

Posted by: Ted at 09:17 AM | category: SciTech
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