Nuclear batteries for all

[Darth Wong]

So it's like carrying a young woman on your back. That must develop strong legs!

[FireNexus]

The 1950s was a truly goofy period. People were very optimistic about the future because they had seen so much recent progress, and they hadn't yet discovered the dark side of technology. Hell, even in the 1960s the average person still didn't really have a handle on what radiation could do to people. That's why all of the comics in the 1960s used radiation as a way to give people super-powers. Today, nobody would write that because we know it would just give you cancer and kill you.

That reminds me of the Family Guy episode where the Griffins rolled around in toxic waste and got super powers. Mayor West did the same in order to stop them, but all he got was lymphoma.

[Ted C]

I wonder what the current-to-mass ratio is on a battery like this. How big would it have to be to power a laptop? Or an electric car?

[Ted C]

On the subject, what did happen to the original moon buggy used by the Apollo missions? I know that they didn't bring them back, but if someone lands near that site again, would they be able to put it back to use after some tweaking?

I believe the astronauts who used the moon buggy said that they'd probably be able to get it running again just by replacing the battery, if they were ever to return.

[Simon_Jester]

After forty years? I kind of doubt it. I suspect that all the moving parts have vacuum-welded together.

[GrandMasterTerwynn]

I wonder what the current-to-mass ratio is on a battery like this. How big would it have to be to power a laptop? Or an electric car?

For all nuclear "battery" devices, the amount of power they put out is inversely proportional to the half-life of their source radionuclide. A nuclear battery's mass is also mostly shielding. The RTGs that power the Voyager spacecraft use four kilograms of fuel, produce 160W of electrical power; but masses thirty-seven kilograms, and produces 2.4 kilowatts of heat.

The nuclear "battery" in the article is probably what's known as a betavoltaic device, which produces electricity when the high-energy electrons produced in the beta decay of certain radionuclides pass through a semi-conductor and kick some of the electrons therein up into the conducting band. The best material for this is tritium, since the electrons have a mere 5.7 keV of energy, so you don't need much shielding (no more than the glass casing) to stop them.

The problem is that these sort of batteries also have abysmal current-to-mass ratios. Two or three orders of magnitude worse than a chemical battery. The strength of something like this is that it will provide a predictable current supply for decades. The only way it'd power your laptop is if it were a trickle-charger for the laptop's chemical battery . . . so you could occasionally use it without needing to find a power outlet.

[Sea Skimmer]

I believe the astronauts who used the moon buggy said that they'd probably be able to get it running again just by replacing the battery, if they were ever to return.

I’m pretty certain it was one of the original designers who said that in fact Those buggies were engineered and built to the highest possible standards of the time and I see no reason why they should not still work after being in such a stable environment. People easily get cars running that have been sitting for 30-40 years or even much longer all the time.

[AdmiralKanos]

The biggest concern is metal diffusion welding, but that depends on how the materials are joined, and what kinds of materials they are. If you put two pieces of steel tightly together in vacuum, they will eventually start fusing together. However, I haven't researched the process well enough to know how quickly it proceeds, or how it is affected by dissimilar material joins. Obviously, lower-pressure joins help as well. If the two pieces of steel are only in loose contact, it's not the same as the two pieces of steel being pushed strongly together.

[PeZook]

The buggy is a simple construction, really: a folding alluminium frame, alluminium legs with a wire mesh instead of tires and four electric motors in every wheel. The instrumentation is at the highest risk, I'd think, along with the batteries.

[Sea Skimmer]

The thing weighed about 450lb and was designed to carry a payload of over 1,000lb much of which is no longer present. I really doubt its moving parts are under any great pressure.