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Discussion Starter #1
A traveling-wave engine to power deep space travel

A University of California scientist working at Los Alamos National Laboratory and researchers from Northrop Grumman Space Technology have developed a novel method for generating electrical power for deep-space travel using sound waves. The traveling-wave thermoacoustic electric generator has the potential to power space probes to the furthest reaches of the Universe.

In research reported in a recent issue of the journal Applied Physics Letters, Laboratory scientist Scott Backhaus and his Northrop Grumman colleagues, Emanuel Tward and Mike Petach, describe the design of a thermoacoustic system for the generation of electricity aboard spacecraft. The traveling-wave engine/linear alternator system is similar to the current thermoelectric generators in that it uses heat from the decay of a radioactive fuel to generate electricity, but is more than twice as efficient.

The new design is an improvement over current thermoelectric devices used for the generation of electricity aboard spacecraft. Such devices convert only 7 percent of the heat source energy into electricity. The traveling-wave engine converts 18 percent of the heat source energy into electricity. Since the only moving component in the device besides the helium gas itself is an ambient temperature piston, the device possesses the kind of high-reliability required of deep space probes.

The traveling-wave engine is a modern-day adaptation of the 19th century thermodynamic invention of Robert Stirling -- the Stirling engine -- which is similar to a steam engine, but uses heated air instead of steam to drive a piston. The traveling-wave engine works by sending helium gas through a stack of 322 stainless-steel wire-mesh discs called a regenerator. The regenerator is connected to a heat source and a heat sink that causes the helium to expand and contract. This expansion and contraction creates powerful sound waves -- in much the same way that lightning in the atmosphere causes the thermal expansion that produces thunder. These oscillating sound waves in the traveling-wave engine drive the piston of a linear alternator that generates electricity.

NASA funded the traveling-wave thermoacoustic electric generator research.

Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.

Los Alamos enhances global security by ensuring the safety and reliability of the U.S. nuclear deterrent, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to defense, energy, environment, infrastructure, health and national security concerns.
 

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Someone on the old forum suggested cutting NASA funding and using the funds to fight terrorism. With technology like this we could see this stuff in so many civilian applications it would put your local utility copmany out of business.

Can you imagine the end to the electrical grid? Neighborhood level electrical service say bye bye to propane and natural gas.

Thanks for the spell checker by the way I hope I get time to feegar it out.
 

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alias said:
Any idea what scale this would have to be to provide power for a city or even a suburban block?
I read somewhere that a fision type power unit about the size of a small home could power over 1000 homes.

So cut it by a 2/3rds and minus the nasty by product
 

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Discussion Starter #5
The neat thing about minimal information of a theoretical product is that it can be as wonderful as your imagination.

BUT! A nucular Sterling engine! Now that is theoretically cool on a whole new level.

I'll bet powering a spacecraft takes just a couple of watts until transmission is required. Then it probably takes a few tens of watts. So you need a storage system for the Nuke-Sterling energy and fire-off information in timed bursts. I'd guess some sort of capacitor storage. Chemical systems deteriorate faster and mechanical systems, being unavoidably inertial, would mess with trajectory.

Unless you could store energy in a stable, high-energy chemical like...oh....say, Adenosine triphosphate, which has a well-understood pathway for controlled release and recycling of the high-energy bonds. Anybody know of an energy system based on that?

Ribulose
 

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Ribulose Diphosphate said:
The neat thing about minimal information of a theoretical product is that it can be as wonderful as your imagination.

BUT! A nucular Sterling engine! Now that is theoretically cool on a whole new level.

I'll bet powering a spacecraft takes just a couple of watts until transmission is required. Then it probably takes a few tens of watts. So you need a storage system for the Nuke-Sterling energy and fire-off information in timed bursts. I'd guess some sort of capacitor storage. Chemical systems deteriorate faster and mechanical systems, being unavoidably inertial, would mess with trajectory.

Unless you could store energy in a stable, high-energy chemical like...oh....say, Adenosine triphosphate, which has a well-understood pathway for controlled release and recycling of the high-energy bonds. Anybody know of an energy system based on that?

Ribulose
Darn scientists.
 

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We recently looked at a company offering a vertical axis wind power turbine scalable to different sizes ranging from nearly as big as the giant 200 ft. diameter props you see on wind farms down to home sized units (if your home is in the Dakotas, Wyoming, etc.). Efficiency is claimed to be pretty extraordinary, and electricity cost to be market-competitive even on a non-subsidized basis. It'll be good to see this sort of technology developed and become more prevalent. One of the issues I have with the current administration is their complete unwillingness to focus any attention or funding on alternative energy - it's an almost religious aversion. Unfortunately, the market will drive development in the form of rising fuel prices, sooner or later.
 

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Discussion Starter #8
What would happen if the gov subsidized development of any technology? Take for example, space exploration. We essentially converted war machines like the V-2 rocket, complete with German rocket scientists, to dual-use purposes--ICBM's and manned space missions. What would have happened had the gov NOT done the subsidization of civilian space exploration?

In my estimation, private enterprise would have entered that domain in the 1970's and driven space exploration from profits rather than tax deficits. That would have allowed people willing to risk assets to make money off of the venture. Instead, we had a buncha bureaucrats and aig-hayeds decide the direction of space. What do we get for that? We get purdy pitchers of space from the Hubble and we get some moon rubble. SFW?

Now that private enterprise has entered the launch business, we're likely to see a lot more cost-effective and practical development that the consumer and investor, rather than all citizen, pays for. I prefer that the risk-takers and consumers pay for things they want rather than me, through government coercion.

Bot
 

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Were there many companies willing and able to pursue space travel since the 50s? Plus the spin off of technology has been amazing. Even given that the best stuff is still kept from the masses.

We are just starting to see private industry taking on the challenge, and mostly expense, for transport vehicles.

While not an authority I would hazard that were it not for the gov's involvement in space travel, we would not be typing on computers
 

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Discussion Starter #10
alias said:
Were there many companies willing and able to pursue space travel since the 50s? Plus the spin off of technology has been amazing. Even given that the best stuff is still kept from the masses.

We are just starting to see private industry taking on the challenge, and mostly expense, for transport vehicles.

While not an authority I would hazard that were it not for the gov's involvement in space travel, we would not be typing on computers
I don't know of any private companies looking at rocketry unless they were trying to seel technology to DoD. Congress recognized a civilian component and forced USAF to spin-off NASA. USAF kept NASA research under tight control for a long time. But gradually it has become increasingly non-military.

The same is true of space products. Stuff that you can buy commercially today were state secrets 30 years ago. This is especially true in remote sensing.

Imagine what kind of cars we would have today if the gov had as tight control on the auto industry 100 years ago as it has had on space technology for the past 50 years. Look atthe auto transformation over its first half-century and compare that to space industry.

Seen any mass-produced spacecraft? Why not?

No market. Why not?

Ribulose
 

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Discussion Starter #12
Manned? I guess so. But that wont be the money-maker. Light launch of communications and special-purpose remote sensing packages.

The other thing that has interesting potential are the extremely slow, high-flying unmanned soaring aircraft. They would be a great platform for civilian use in crop management, water resources management, shipping, traffic mgmt, etc. Not to mention HS. Want to patrol a border 24/7 at 70K ft with targetable high-res electro-optical sensors?
 

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Teledesic (I think that’s the spelling) contractors did a lot of work on rocketry recently and, I forget the name but there was a company funded by Paul Allen that was the first private industry to send someone to space. This was a couple of months ago.

Also, about government control of technology, friends have said to me in a non-disclosure non-detailed kind of way that there are many elements of advanced electronics that are under tight control. Many of these are related to NASA technology. This is handed down knowledge.....of course, but from folks who have worked in small ways on some projects....
 

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alias said:
Teledesic (I think that’s the spelling) contractors did a lot of work on rocketry recently and, I forget the name but there was a company funded by Paul Allen that was the first private industry to send someone to space. This was a couple of months ago.

Also, about government control of technology, friends have said to me in a non-disclosure non-detailed kind of way that there are many elements of advanced electronics that are under tight control. Many of these are related to NASA technology. This is handed down knowledge.....of course, but from folks who have worked in small ways on some projects....
That company was SpaceOne.

Sea launch is a great example of the private sector coming up with some new non ground based launch platforms. I have a family friend that works for them. The brains sit in Khalifornia watching video feeds and weather reports while a small crew goes out to launch the rocket at a very reasonable expense. I wonder when satellite production will increase it still takes several years to produce a simple communications bird.
 

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Discussion Starter #15
I wonder how much of the time in satellite construction comes from justifying a heavy lift launch. I mean, if you're using a big launcher but you only need a 50 Kg payload, to justify the expense of the payload you get partners involved who can piggy-back their payload. This means you gotta design a bigger payload packaging system and power supply and the value of the payload goes up, while individual $/Kg drops. So you may go from 10 million dollars to launch your 50 kg and 10 million to launch a 200 Kg package. Wow, what a savings if you get the partners in! But the value of the whole satellite goes way up. Each player's individual investment drops but the launch becomes hugely expensive and you gotta make sure the complex package gets it exactly right.

But if you had a cheap launcher with small lift you launch small, cheap satellites on-demand rather than on accumulation.

Perhaps this is the analogy of trucking vs rail shipping?

Rib
 

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Putting all your eggs in one basket comes to mind. Although they have the launching down to a science (hehe) a mishap with a 200 million dollar payload is better than a mishap with a 600 million payload. Just the insurance risk alone would skyrocket the cost.

On the other hand insuring the cargo might be even cheaper because insurance companies or investors would share the risk.

I'm gonna give my sea launch buddy a call.
 
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