Главная > Реферат >Остальные работы
Nano Technology Essay, Research Paper
18 seems to be the magic number in today’s manufacturing process. Intel and AMD both boast their upgraded production, and note that it will lead to ever increasing speeds and capabilities. Quietly, however, there is a growing consensus among the scientific community that silicon based-chips are on their way out. Tiny, molecular computers are becoming more and more feasible, and may do to silicon what transistors did to vacuum tubes.
Across the world, universities and government institutions are making advances in nano-technology that could shatter today’s concept of electronics. As far as speed and memory are concerned, the results may be incomprehensible to consumers and businesses alike.
Consumers are routinely fooled by the false-security of a megahertz rating. Most buyers think an extra 50Mhz is appealing, despite a $75-$100 increase on the price tag. True, a 550 Pentium 3 has a 10% speed advantage over a 500 Pentium 3, but it realistically only performs a 5% increase in most applications. Consumers need to understand that speed and performance are mutually exclusive. An extra 100 bucks is hardly worth the 10-12-millisecond improvement when launching Microsoft Word. Still, an 800 Athlon this Quarter, a 900 next Quarter, seems to signal the dominance of silicon-based computers for some time. Most computer-chip manufacturers estimate that they will have plenty of business until 2014 when they expect to reach their theoretical limit in silicon-based computers: .10 microns. The translation meaning processors and other components would be built at 100-billionths of a meter, or 100 nanometers- 100 nanometers being the distance between each transistor.
Now, realize that with nanotechnology we could shrink components down to .001 microns- one nanometer. Chips would be exponentially faster, more efficient, and powerful than anything on the drawing board today. While some labs, like the ones at UCLA, IBM, and HP are well publicized, many are working under top-secret conditions and have supposedly made several prototypes of working nanotechnology. One such rumor is of a molecular device capable of functioning as RAM in a nano-computer.
The impact would be tremendous on the scientific and commercial communities. A near-term application in 2-5 years might be a DVD-like movie stored in a space half the size of today’s semiconductor chips.
If nanotechnology were to exist today, it would make every CEO in the computer chip industry cringe at the costs they have endured to produce the latest and greatest chips. Current chips are made in multi-billion dollar fabrication plants (fabs) that use light waves to etch layers of circuitry onto a silicon wafer. It is an enormously expensive process, mostly because of the conditions in which the “clean rooms” must be maintained. Any dust or particles in the room would contaminate the chips produced. Nano-produced computer components would not require any such plant. While the current trend provides that with the advances in computer technology, the more ‘finicky’ they are to produce. Molecular computers would have their components produced in vast numbers without such hindrances. One such idea involves massive “self-assembling” vats that produce the chips using chemical reactions at a fraction of current costs.
The idea behind nanotechnology is in reproducing what nature already does: produce things atom-by-atom, molecule-by-molecule. Not only would this allow humans to control properties like color, texture, and density, but also it might be possible to create things that repair themselves when damage occurs. Self-Assembly seems to be a key concept in the nanotechnology movement, which was revolutionized only ten or so years ago.
While the idea is not new, advanced microscopes and computer software have brought it from theories and crazy ideas to feasibility. For instance, in 1990 IBM brought nanotechnology to the headlines when it spelled IBM with 35 atoms of the element xenon.
Nanotechnology carries with it the idea of building anything imaginable, from a diamond coat to paint over your car (to prevent scratches), to diagnosing illnesses from one droplet of blood.
In 1998, the White House Science and Technology Council created the Interagency Working Group charged with developing ideas for future nanotechnology in 10-20 years from now. They have drawn up ideas about curing cancers and legions on the body with nanoparticles traveling through the body to fix it from the inside. Artificial limbs could be made up in batches and its prospective owner would personalize prosthetic limbs for use. Of course, memory and storage would be millions, if not billions, of times faster and larger.
Unfortunately, we are still in the blueprint and laboratory stage. An Interagency Working Group report noted that nanotechnology today is where transistors were in the 1950’s. Problems persist, not with the application of such technology, but with the execution of it.
No one, for instance, has discovered a way to link all the nano-particles, which process data as 1’s and 0’s together. And it was only recently that UCLA was able to get the components to repeatedly work. Basically, it could only work with data once, and could not switch back and forth between the 1’s and 0’s. As with any other technology, the bumps in the road and problems to come will meet with new questions and innovative solutions.
But the most exiting part of the whole nanocomputer idea is that it will require radically different architecture that would look alien to any computer engineer working in today’s laboratories. At the Massachusetts Institute of Technology, they are working on architectures that resemble their biological counterparts in mammal brains. The idea is to assemble trillions of circuits and then map out and identify the good and bad pathways- much like the human brain. A simplified comparison might be declaring faulty sectors on hard-drives off limits for reading/writing. Possibly, that could mean every nanocomputer would be unique and personalized-much like the human brain. The ideas are innovative and most go out on a tangent from current doctrine. A program manager at the Pentagon’s Advanced Research Projects Agency noted, “We don’t want to be standing on the shoulders of silicon.”
Recently, IBM showed how the circuitry of atomic scale computing could be achieved. Called a “quantum image” the technique demonstrates that it could one day be technologically practical to make a nano-circuit. Heat would be virtually eliminated and batteries that never die out might power the computers. The IBM researchers found that they could project the image of one cobalt atom (about 20 nanometers) onto a second point within the same area. This experiment proves that it is possible to read and write 1’s and 0’s without the benefit of wiring. The research is the benefactor of the increasing wealth of IBM and thus its augmented Research and Development budget.
All this comes as the Clinton Administration, along with bipartisan support in Congress, proposes an increase from $260 million to $487 million dollars in nanotechnology research. The increase will mostly benefit University research and joint ventures like the UCLA-Hewlett Packard alliance. Federal agencies like the National Science Foundation, the Department of Defense, the Energy Department, NASA, the National Institute of Health and the Commerce Department will all have earmarked funding for nanotechnology development.
Will the new millennium herald us into a new era of computing and personal electronics? Yes. Will we see nanotechnology tomorrow? No. In 10-20 years, however, supercomputers might be the size of calculators and consumer computers may fit on your watch. No one can predict the new abilities we will have or the upcoming products that will fill our closets after we don’t want to use them anymore. In the end, the only real question that remains is: What kind of games will run on these bad boys?
What objects we commonly know should disappear because of nanotechnology?
People living before and through the transition – at first and because of prejudice for things we know and because people have not imagined the variety and super rich realm of new possibilities — the objects failure to everyday life will be sought by the public and reproduced by assembler technology. People will still want cotton beach towels, although the cotton farmer will no longer be needed when fibers can be manufactured atom by atom from carbon in the air or from limestone. Lots of familiar items will appear “traditional” on the outside, yet posses a multitude of new tricks and functionality made possible with MNT — cars with Utility Fog crash protection for instance. Of course, MNT Smart Materials can look like anything, yet perform “magic”.
Now, the next generation and generations to follow, born into the age of nanotechnology will a “clean slate” without concrete historical prejudices, will design objects and lifestyles that take advantage of the new wealth of possibilities and I should expect design objects and “environments” that would appear bizarrely alien, extraordinarily novel to even the most advanced nano tinker today. The general concept is familiar in science fiction, only now we have a clear engineering path to make real, the stunning constructs of uninhibited imaginations and those yet to be born.
The wild card to consider and the reason that frankly, it is ludicrous to project past a few decades — or more than say, one generation or so, is the effect nanotechnology will have on intelligence enhancement efforts. Once these efforts are even mildly successful, the the “experimenters” will spend much of their time amplifying intelligence enhancement efforts and the valve controlling what is imaginable and what can be engineered opens at a geometric rate. By definition, what can and will be is unimaginable now, and I’m not even addressing the issue of machine intelligence in the equation. The curve approaches vertical.
What new objects should appear because of nanotechnology?
Perhaps the big story — with mature nanotechnology, any object can morph into any other imaginable object… truly a concept requiring personal exposure to fully understand the significance and possibilities, but to get a grip on the idea, consider this:
The age of digital matter — multi-purpose, programmable machines, change the software, and something completely different happens.
A simple can opener or a complex asphalt paver are both, single purpose machines. Ask them to clean your floor or build a radio tower and they “stare” back blankly. A computer is different, it is a multi purpose machine — one machine that can do unlimited tasks by changing software… but only in the world of bits and information.
I’m involved with a company developing Fractal Shape Shifting Robots. Fractal Robots are programmable machines that can do unlimited tasks in the physical world, the world of matter. Load the right software and the same “machines” can take out the garbage, paint your car, or construct an office building and later, wash that building’s windows. In large groups, these devices exhibit what may be termed as macro (hold in your hand) sized “nanobots “, possessing AND performing many of the desirable features of mature nanomachines (as described in Drexler’s, Engines of Creation, Unbounding the Future, Nanosystems, etc.). This is the beginning of “Digital Matter”.
These Robots look like “Rubic’s Cubes” that can “slide” over each other on command, changing and moving in any overall shape desired for a particular task. These cubes communicate with each other and share power through simple internal induction coils, have batteries, a small computer and various kinds of internal magnetic and electric inductive motors (depending on size) used to move over other cubes (details here). When sufficiently miniaturized (below 0.1mm) and fabricated using photolithography methods, cubes can also be programmed to assemble other cubes of smaller or larger size. This “self-assembly” is an important feature that will drop cost dramatically.
The point is — if you have enough of the cubes of small enough dimension, they can slide over each other, or “morph” into any object with just about any function, one can imagine and program for such behavior. Cubes of sufficiently miniaturized size could be programed to behave like the “T-2″ Terminator Robot in the Arnold Schwartznegger movie, or a lawn chair… Just about any animate or inanimate object.
Fractal Shape Shifting Robots have been in prototype for the last two years and I rather expect this form of “digital matter” to hit the commercial seen very soon. In the near future, if you gaze out your window and see something vaguely resembling an amoeba constructing an office building, you’ll know what “IT” is.
This is not to say individual purpose objects will not be desirable… Back to cotton — although Cubes could mimic the exact appearance of a fuzzy down comforter (a blanket), if made out of cubes, it would be heavy and not have the same thermal properties. Although through a heroic engineering effort, such a “blanket” could be made to insulate and pipe gasses like a comforter and even “levitate” slightly to mimic the weight and mass, why bother when the real thing can be manufactured atom by atom, on site, at about a meter a second (depending on thermal considerations).
Also, “single purpose” components of larger machines will be built to take advantage of fantastic structural properties of diamondoid-Buckytube composites for such things as thin, super strong aircraft parts. Today, using the theoretical properties of such materials, we can design an efficient, quiet, super safe personal vertical takeoff airocar. This vehicle of science fiction is probably science future.
Which industries should disappear because of nano-technology?
Everything — but software, everything will run on software, and general engineering, as it relates to this new power over matter… and the entertainment industry. Unfortunately, there will still be insurance salesmen and lawyers, although not in my solar orbiting city state. If as Drexler suggest, we can pave streets with self assembling solar cells, I would tend to avoid energy stocks. Mature nanites could mine any material from the earth, landfills or asteroids at very low cost and in great abundance. The mineral business is about to change. Traditional manufacturing will not be able to compete with assembler technology and what happens to all those jobs and the financial markets is a big, big issue that needs to be addressed now. I intend to start or expand organizations addressing these issues and cover progress in the pages of NanoTechnology Magazine.
We will have a lot of obsolete mental baggage and programming to throw out of our heads… Traditional pursuits of money will need to be reevaluated when a personal assembler can manufacture a fleet of Porche, that run circles around todays models. As Drexler so intuitively points out, the best thing to do, is to get the whole world’s society educated and understanding what will and can happen with this technology. This will help people make the transition and keep mental, and financial meltdowns to a minimum.
How does the technology evolution of the last thirty years shape the future of your field?
Never before has 30 years been such a long, long time, technologically. I am speaking of course, of the ever increasing curve of advancement in all fields of tech and science.
Imagine a world without cell phones, wireless phones, beepers, fax and answering machines, video tape players, cam corders, cable TV, CD audio, Sony Walkmans, Microwave ovens, Intendo, personal computers and the World Wide Web. Back then, few people had the luxury of a remote control for their tube! I tell ya… it was a dismal dark age of hand operated analog devices. We should fall to the ground in pity for our parents and grandparents and ourselves for the drudgery of just surviving grocery checkouts with no laser readers.
Out side of these extraordinary advances in computer tech, the rise of biotech and genetics has conspired to make people think small. That’s where the power is. Did you see that IBM logo spell out with 35 individual atoms back in the late ‘80? That was done with a new microscope that can not only image individual atoms, but move them around as well. This one act proved definitively that atoms can be manipulated with precision by human beings.
Yes, technology is moving fast! However, something bizarre is on the horizon… and I mean truly bizarre. “Something wonderful.” (Clark)
If you found a genie in a bottle offering the proverbial three wishes, what would you wish for? What? Material wealth? End world hunger? A space condo orbiting the rings of Saturn? Intelligence enhancement? How about the truly grand prize, the ancient dream of (most) all humanity… youth and open ended life span?
If I found a green gen, I would state… only one wish. Something called nanotechnology. Let me explain…
Computers reproduce information at almost no cost. A push is well underway to invent devices that manufacture at almost no cost, by treating atoms like computers treat bits of information. This would allow automatic construction of consumer goods with out traditional labor, like a Xerox machine produces unlimited copies without a secretary retyping the original information.
Electronics is fueled by miniaturization. Working smaller has led to the tools capable of manipulating individual atoms like the proteins in a potato manipulate the atoms of soil and water to make copies of itself (Drexler, Merkle paraphrased). The secret to self replication, biological or synthetic, is prefabricated building blocks. Biology uses atoms. Atoms are as new and squeaky clean as the instant they condensed out of pure energy of the Big Bang, come in 92 flavors (elements), each atom is identical (electronically) to any other atom in a flavor and have the remarkable attribute of sticking to each other like Lego Blocks. They are prefabricated building blocks. Biology uses atoms and soon, so shall we.
This is the shot gun marriage of chemistry and engineering called molecular nanotechnology (MNT). If we can place atoms on a structure under construction individually, this opens up a realm of super large molecules not found in nature, designed by engineers (adhering to the normal laws of chemistry). Structures, big structures, or microscopic structures and machines could be made of materials with unusual physical properties like carbon in its ultra-strong form, diamond. Ideally, programed “nanites”, machines with atomic sized components could take any source of required atoms and energy, make copies of themselves, then “grow” things without traditional manufacturing techniques and without byproducts. No waste and no side reactions means this tech would be super green. Nanites could be programed and unleashed to clean up existing industrial pollution (and will within two decades).
Nanotech’s goal is a device called a “Universal Assembler” that takes raw atoms in one side and delivers consumer goods out the other. It could also make a copy of itself you could give to a friend. What happens to the economy if demand for just about everything is foiled by a household appliance… is a good question.
Scientists are on the verge of manipulating atoms and molecules with the same precision as life. Research in molecular biology, chemistry, and scanning probe microscopy (scopes that can see and move atoms) are laying the foundations for a technology of self-replicating molecular machines by developing positional controlled chemical synthesis. By building objects on such a fine scale, we could make extraordinary things from ordinary matter. If the fields of molecular biology (which some call wet nano), chemistry and solid state physics were all to shut down today and make no more advances, chip manufactures in their quest for evermore speed would develop MNT single handed. They have the incentive.
Society is in for a spin as we head for a novel form of economics in an age of self replicating machinery, where the design of an object cost about the same as today yet production cost is nearly zilch. All first wave manufacturing will be obsolete. No cobblers, just shoe designers, no autoworkers, just car designers, no feed lots, just chefs. Ask yourself, what will be of value? What is money in a nano age? How will politics and war change when we don’t have traditional resources to fight over?
As an example of this new economic era, here is a response to an inquire from a gentleman with the Natural Resources Canada / Resources naturelles Canada:
Subject: hydrocarbon reservoir characterization “I am curious if anybody knows of companies or research organizations that work in the field of hydrocarbon reservoir characterization using nanotechnology?”
Allow me to provide a perspective I think you’ll find very relevant to your industry. I have good news and bad… Perhaps the good news (although disruptive) is so good, you won’t mind the bad.
Nanotechnology, building things atom by atom, is not yet available. This is the level of technology you seek. However, the first “nanotech company” formed to develop this ability is up and running (Zyvex, see: http://www.zyvex.com/).
With reasonably mature Drexlerian nanotechnology (see “what is nanotechnology”, www.nanozine.com) not only could you flood large numbers of nano-robots into a reservoir in order to collect information that characterizes the reservoir conditions, but also program nanites to build capillary collection systems out of the carbon in the oil (diamond), capable of extracting extremely high percentages of a reserve (probably 95-98%). Such nanites could easily be programed and engineered by modifying medical nanites in design right now by Robert A. Freitas Jr. (firstname.lastname@example.org). Also, with the “novel economics” of self replicating machinery that “Drextech” represents, 10^15 oil field nanites would cost only slightly more than developing and building the first.
Now the bad news. Nobody will (probably) ever build them, because the same effort could be used to engineer nanites that deposit molecularly thin solar cells on road and highway surfaces (then add a layer of tough diamond). Canadian roads could supply the world’s energy needs several times over.
Nanotechnology is a truly revolutionary. Yes, this does mean the obsolescence of oil as an energy source. Carbon sources, (most important nano building blocks) are numerous…. the atmosphere and limestone deposits for instance.
The oil business is not alone in the disruptive transition to this most powerful technology. Virtually all manufacturing processes will be obsolete, as will mining and logging. Nanotechnology will allow the syntheses of wood on a molecular level… including smell, with process that exclude our contemporary concept of labor (just extrudes out of the box, pre-sized). The same synthesized wood could be laced with carbon nanotubes (Buckytubes, Fullerenes). Such a “composite” would exhibit structural properties exceeding steel. Diamond will become as common as lumps of coal. Gold could actually be mined from seawater.
As extraordinary as this sounds, a little research on the web (you may have already) will tell the same story. While you’re researching, you’ll no doubt also discover the extremely positive benefits of nanotechnology. We are on the threshold of material opulence and greatly enhanced physical health. You will find these and other subjects of significance on the Magazine’s webpage such as, “What will be monetarily viable industries in the nano-era?” and the all important question, “What’s the time frame?”
Best in the future (it’s going to be a very different place), Bill.
Stop. Who thought all this up? Where did this outrage originate? Dr. K. Eric Drexler is the father of nanotechnology, seeing the pattern of the posable in his studies of biology, computer science, etc. while still a student at MIT in the late seventies. He realized what a different word we could have, if we could build with individual atoms like nature. Drexler (and Dr. Chris Peterson) fought one heck of an uphill battle throughout the ’80s and ’90s for acceptance of these radical ideas by the scientific community. Now, things have changed. History will read, Newton, Einstein, Drexler.
Yes, we are on the threshold of material opulence and greatly enhanced physical health. However, in a bed of roses, one still must avoid the thorns. Like all technology, nano can be used for good or not so good (serious understatement) and could cause considerable panic to the under informed during the transition. As post-nano international relations thinker Tom McCarthy points out, if China’s perception of its ancient rival India’s advanced software and technology lead… might produce nanotechnology first, this could prompt China to nuke Indian research centers before India could strike with nanoweapons. Now conceder this; unlike nuclear, nano is a desktop industry… and one sufficiently advanced disgruntled hack working in a garage could program a self replicating nanite to kill all bovine on the planet, or all people with brown eyes, or indeed, all DNA based life…
But wait, check this small example of the wonders possible building things with atomic precision.
Building on the atomic scale, mechanical computers with the power of a mainframe could be manufactured so small, that several hundred would fit inside the space of a biological cell. (http://www.asiapac.com/EnginesOfCreation/)
If you combined microscopic motors, gears, levers, bearing, plates, sensors, power and communication cables etc., with powerful microscopic computers, you have the makings of a new class of materials. Smart materials.
Programmable smart materials could shape-shift into just about any desired object. A house made of smart materials would be quite useful and interesting. Imagine a wall changing color at your command, or commanding the appearance of a window where there was none, drapes of any style listed in the smart materials software or from some source on the Internet. This is all purely mechanical and can be done today, although with much larger parts, resulting in a coarser effect (and at great expense!).
A fabulous type of smart material was invented by Rutgers University’s Dr. J. Storrs Hall, computer scientist, moderator of the sci.nanotech news group and seriously creative nanothinker. He calls his brainchild, Utility Fog. (http://nanotech.rutgers.edu/nanotech/Ufog.html)
This “intelligent” polymorphic (shape changing) substance consists of a mass of tiny identical nanoengineered robots. Each utility foglet robot is mostly telescoping arms 5 to 10 millionths of a meter long with a central globular body 1 or 2 millionths wide housing motors, a battery and one of those powerful nanocomputers. Dr. Hall designed the ‘bot with 12 arms that can be waved back and forth and grip the ends of other robot arms, making power and communication connections. 12 arms, so some could be free briefly when changing neighbors and still be connected to the mass. Also, such an octet truss structure (invented by Buckminster Fuller) remains rigid even if all the arms are connected to the bodies by simple hinges This avoids a more complicated attachment assembly.
Each robot body is small compared to its arm spread, and the arms are relatively thin. This results in the foglet taking up only 2 or 3 % of the space in a volume they fill, the balance is left for air and passing light. A room filled with Utility Fog would be fairly transparent, larger volumes would become cloudy at a distance.
Much larger foglets can be built with today’s technology however, the expense of producing enough to do anything useful would be most prohibitive. Filling an average house with the microscopic variety would require trillions of foglets, so the whole concept depends on the economics of automatic nano-assembly to be remotely affordable.
Now for the fun part. With all this computing power, these puppies can be programmed with a wide spectrum of behaviors that mimic materials of different mass, motion, appearances and functions. Each Foglet can sense the force along each and every arm, and react according to the magnitude and relation of those forces.
In the words of Dr. Hall in a recent article in NanoTechnology Magazine, “If the program says, extend when the force is trying to stretch, retract when it is trying to compress, you have a soft material. If it says, resist any change up to a certain force, then let go, you have a hard but brittle material. If the programming says, maintain a constant total among the extension of all arms, but otherwise do whatever the forces would indicate; and when a particular arm gets to the end of its envelope, let go, and look for another arm coming into reach to grab; you have a liquid. If you allow the sum of the arm extensions to vary with the sum of the forces on the arms, you have something that approximates a gas within a certain pressure range. Note that because the Foglets can use their own power to move or resist moving, the apparent density and viscosity of the fluid can be anything from molasses to near vacuum.”
Further Dr. Hall states, “Run a distributed program that at a specified time, changes a certain volume from running water to running wood. A solid object would seem to appear in the midst of fluid. It can just as easily disappear. Now fill your entire house with the stuff, running air in background mode. Have an operating system that has a library of programs for simulating any object you may care to; by giving the proper command you can cause any object to appear anywhere at any time. You could carry a remote control, which might happen to be shaped like a wand with a star on the end…
More ambitiously, since you’re embedded in the Fog, it can sense every detail of your bodily position. It forms a “whole-body dataglove”, and you can control it with extremely subtle gestures. At the ultimate extreme, the Foglets can carry various special sensors ranging from simple electrodes with voltmeters to SQIDs and form an extremely high bandwidth polygraph. With proper programming the Fog would almost be able to read your mind. This combination of extreme reactivity to control and virtually limitless creative and operational ability suggest a comparison with the Krell machine in “Forbidden Planet”.
Hall offers the average person with a bucket of Utility Fog a great stage career in Vegas with these observations. “Thus, here’s a short list of the powers you’d have or appear to have if embedded in Fog:
Creation: causing objects to appear and disappear on command. Levitation: causing objects to hover and fly around. Manipulation: causing forces (squeezing, hitting, pulling) on objects (real ones) at a distance. This includes a distance of inches; bend steel bars (real ones) like Superman. Teleportation: nearly any combination of telepresence and virtual reality between Fog-filled locations. Shape-shifting: Want to be a mouse? the Fog around you simulates very large feet, baseboards, etc., while your telepresence drives a mouse-sized fog program. Want to be the Statue of Liberty … ?”
- Technology Essay, Research Paper In a conversation with Tom Hauck, we discussed about how technology has ... will say yes). Finally Nano technology has many theoretically sound principles ... away from practical use of Nano technology. I believe pretty soon we ...
- Technology Essay, Research Paper Technology How has technology changed? It has changed drastically ... an IBM P/S 1. It was about nine years ago, the price was ... of pc s dropped as the technology grew. Also a new p.c. entered, it ...
- Technology Essay, Research Paper To sign up for Easy ... page will appear. Enter your name, address and phone number. Click ... new e-mail address and user name. Now you are ready to ... that tells you the computer s name, the location of the information ...
- Technology Essay, Research Paper Technology is a great thing, it aids ... . But there are times when technology can be the greatest downfall ... the Manhattan Project, the code-name for a top-secret project which ...
- Nano-Technology Essay, Research Paper One of the big problems ... appreciated with current ideas in nano technology research is the energy requirement for ... on the planets. The present technology does not allow satellite transmission ...