Archive for August, 2005

Nanosatellites

August 24th, 2005 by dstmartin
 

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It’s like something out of Star Wars – a tiny satellite that keeps a close-up eye on orbiting spacecraft. We’ll take a look, too – today on Engineering Works!

One of the big problems with flying spacecraft into orbit is that astronauts can’t see very well what’s going on outside. That could be why the space shuttle Columbia was lost in 2003. Nobody knew that a piece of foam had damaged tiles that were supposed to protect the shuttle from re-entry heat.

Even before that, NASA engineers were working on a miniature satellite that could give future astronauts a clearer view of what’s going on outside their spacecraft. The satellite is about the size of a volleyball and weighs about 10 pounds.

Tiny xenon gas engines will move it from place to place outside the space shuttle or the International Space Station. It will use camera-on-a-chip imagers to see what’s going on and a global positioning system, or GPS, will help controllers keep track of where it is.

The computer control system is based on a microprocessor from a Power PC computer. Its designers expect that it’ll even be able to launch and refuel itself. And either astronauts in orbit or ground controllers will be able to fly the satellite into position.

The pint-sized satellite also should help astronauts working on the International Space Station inspect the outside of the orbiter without having to make a space walk to do it.

Our orbit is taking us out of range. See you later.

Image courtesy of NASA/ Johnson Space Center

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Nanowires

August 17th, 2005 by dstmartin
 

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Here’s a scary thought – threading an electrical wire into your brain. Some engineers think it might be a good idea. We’ll see why – today on Engineering Works!

Actually, threading an electrical wire into your brain isn’t really a new idea. Engineers have just worked out a way for medical researchers to do it. Physicians already thread lots of things into our bodies to find things out or treat illnesses – heart catheters, especially. This is just taking the idea a little farther and a lot smaller.

Being able to thread tiny wires into your brain could help pinpoint brain damage from injury or stroke, find tumors, maybe help people with Parkinson’s disease.

In experiments, researchers are using platinum nanowires – wires so thin that it takes 20 or 30 of them to be as thick as one strand of your hair. This thinness is important because wires that small won’t get in the way of blood flowing through even the tiniest blood vessels.

The next step is to use nanowires made of special polymers that conduct electricity. They’re even thinner – 20 or 30 times thinner. They’ve got another nifty quality, too. They change shape when they’re electrified. Changing shape should help them change direction through the complex tiny blood vessels in the brain.

Eventually, engineers think they’ll be able to keep track of what individual neurons – nerve cells in the brain – are doing.

Our brain is working just fine, thank you. But we’re done. See you next time.

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Programmable Cells

August 10th, 2005 by Gene
 

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Computers are getting smaller all the time. Some engineers are taking this idea to extremes. We’ll check it out – today on Engineering Works!

These engineers are looking into a new field of science, or technology called synthetic biology. The idea is to use living cells to do many of the things computers based on silicon chips do now, plus some other things – detect hazards, build structures, repair tissues and organs inside the body. It sounds like something out of a bad movie, but these guys are serious.

For instance, some electrical engineers have already programmed bacteria cells to glow red or green when they get a chemical signal from other bacteria cells. When they sense a high concentration of the signaling chemical, they glow green. When there’s less of the chemical, they glow red.

But that’s not all. One engineer has programmed cells so they make a red-and-green bull’s eye around the chemical that’s signaling them. Red close in where there’s more chemical. Green farther out, where there’s less.

The researchers are pretty excited about that bull’s eye. It could be the first step on the way to using programmed bacteria to build stuff, maybe fix things inside your body. If they can program the cells to turn colors, they think they can get them to deposit other stuff when they get the right signals.

We don’t know about our cells, but our program is just about over for this time. See you later.

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Tidal Power

August 3rd, 2005 by dstmartin
 

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Electricity may not make the world go ’round, but it’s close. We’ll take a look at one way engineers think we might produce more – today on Engineering Works!

Electricity powers our lives these days. Life without it would be a lot different – no cell phones; no computer; no air conditioning in the summer; no electric lights. We use a lot of electricity.

Engineers in Great Britain think they have come up with a new way to use one of the oldest ways of generating power: water; ocean tides, actually. Their idea is to put big turbines inside big tubes that’re anchored to the ocean floor. When the tide goes in and out – which happens twice a day, every day – the force of the water would spin the turbines. No fuel, no pollution; lots of electricity. The engineers estimate that one turbine 100 feet across could produce at least 1.5 megawatts of power. That’s enough to provide power to 1,500 homes for a year.

And just in case you wondered, if you look at how much electricity each of us uses, here in the United States, we’re not such energy hogs after all. People in Canada, Iceland, Norway, Sweden, Finland, the United Arab Emirates and Kuwait use more electricity per person than we do. In Iceland and Norway, it’s more than twice as much.

Well, it’s time to turn out the lights and go home. See you next time.

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