Generating electricity for deep space probes

[ToSeek]

A traveling-wave engine to power deep space travel

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.

Power is always at a premium for deep space missions like Cassini and New Horizons. This could allow for more science to be done without going the full-nuke route (that probably requires a much larger spacecraft, anyway).

[zebo-the-fat]

Very nice!
If I understand the idea correctly, the radioactive isotope is used as a heat souce to run the engine. Could solar power be used to drive it for missions close to the sun?

[sarongsong]

...and for an earth-bound application:
"...This [deep-space generator] is the latest application of the TASHE, which is also being developed to liquefy remote reserves of natural gas for a more economical transport of this fossil fuel resource to market than previously possible."
http://www.aip.org/pnu/2004/split/695-2.html

[zebo-the-fat]

Use a camp fire to heat it so you can use your microwave oven in the great outdoors!

[ToSeek]

Very nice!
If I understand the idea correctly, the radioactive isotope is used as a heat souce to run the engine. Could solar power be used to drive it for missions close to the sun?

If you're close enough to the Sun, I think you'd just use solar panels since they turn the energy straight into electricity. The alternative, I suppose, would be to have something that the Sun heats, but that would be bulky and (I think) inefficient.

[zebo-the-fat]

Very nice!
If I understand the idea correctly, the radioactive isotope is used as a heat souce to run the engine. Could solar power be used to drive it for missions close to the sun?

If you're close enough to the Sun, I think you'd just use solar panels since they turn the energy straight into electricity. The alternative, I suppose, would be to have something that the Sun heats, but that would be bulky and (I think) inefficient.

I don't know how efficient solar panels are compared to this gizmo, I would think it would be more resistant to damage from micrometeors, radiation etc. but that's pure guesswork

[Glutomoto]

Sound ? Would the accoustic vibrations be bad for spacecraft instsruments ?

Helium ? Isn't it hard to store ? How much helium is lost during engine operation. I guess the helium could also cool the infra-red detectors.


I still want one, it would be neat to have a solar fired earth cooled engine.

[TrAI]

I don't know how efficient solar panels are compared to this gizmo, I would think it would be more resistant to damage from micrometeors, radiation etc. but that's pure guesswork

Well, I think the efficiency is something like 5%-30% depending on technology.

But I would think the concentrators(mirrors or lenses) for the solar powered traveling-wave generator would have to have comparable surface area to a solar panel. You also have the question of frequency sensitivity, as the TWG would likely use far IR(heat radiation) while a solar panel might use visible and near IR light, and the sun doesn't emit the same amount of power in the whole spectrum.

I expect the TWG would be best coupled with a radioisotope or even fission heat source.

[ToSeek]

New Scientist coverage:

Spacecrafts powered by thunder

[ToSeek]

Or sticking with solar cells:

Next generation solar cells may someday power NASA's robotic explorers