Sci-Fi Civilian Vehicles, Equipment and Technology

Okay, it's not totally implausible, but it feels like something we shouldn't expect to have in private hands any time soon.

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

I figured we'd use them for civic issues like data backups, essential utility sensors, or isolated security systems. Things where you can burry the RTG in concrete or keep them under armed guard.

If you're going to do that, use miniaturized fission reactors. The reason we employ RTGs on spacecraft is that they are virtually maintenance free and last for decades, not because they are particularly power-dense. The generator on the Perseverance Mars rover outputs about 110 watts and slowly degrades over time. It weighs 45 kg, with fissile material weighing 4.8 kg. For peak power output, the generator charges batteries, which can discharge to deliver up to 900 watts.

Pu-238 is not something that you find lying around in the grocery store and definitely not something to stick in an off-the-shelf commercial product, even if it's only used at a grid or enterprise level.

I'm trying to find information on data center power usage. I see that individual racks can use up to 60 kW, so a little bit of napkin math says that to keep one of those running on an RTG backup, it would need 2.6 tons of plutonium dioxide. At that point we're far beyond commercial power and well into weapons proliferation... or rather, rebuilding society from the aftermath of nuclear armageddon.

Edited by Fighteer on Mar 2nd 2024 at 10:43:15 AM

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

(Pedantic, but you can't use battery grade plutonium for nuclear weapons. While it is in theory bomb-grade, the heat output would do a number on the actual bomb design)

"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." - Richard Feynman

Im not sure why you would want nuclear-powered everything. Conventional powersources work perfectly fine with existing backups in the real world.

Data centers today use commercial battery backup systems: think Tesla Powerpack and Megapack or the equivalent. These are perfectly adequate for the task of keeping them running for short durations and have the added benefit of not using tons of toxic, radioactive materials.

My search yesterday revealed that Google plans to have all its data centers operate on 100% renewable energy, meaning wind/solar with battery storage. Not only is this good for the environment but it means they can maintain greater reliability since they aren't subject to grid failures.

Nuclear power can indeed be a grid-scale baseline: able to sustain demand under nearly any conditions. Maybe in the future we'll have the promised compact fission reactors that can be deployed off-grid and safely operated under less rigorous regulatory scrutiny. Those aren't just being developed for use on Earth, but for places like the Moon, where there is no electricity grid and solar power is unavailable for 14 out of every 28 Earth days.

It's not inconceivable that you may some day be able to homestead on Mars with your Fission Pro 2000.

Edited by Fighteer on Mar 3rd 2024 at 10:34:30 AM

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

Any condition except, well, rapidly changing power demands. it's only really good at a constant power output

Right, that's why you use nuclear as the backstop, with renewables and battery storage to handle the variance.

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

Yea but i mean as in: if your goal is to provide continuous power in case of emergencies for your storage drives, nuclear isn't a great option. Same for the sensor or security system examples. Conventional systems existing today do just fine: a generator or a battery can provide power in seconds. In fact for the sensor example in specific, i'd argue environmental energy harvesting systems would be vastly superior. Like, using vibrations, heat, soil chemistry, whatever. Never runs out, always works, the only downside is that the provided energy tends to be really low.

Nuclear's one of those things that's IMHO doomed to be a niche technology: it's really good in some specific cases, it's far from a silver bullet.

You certainly don't want to run a car on nuclear power.

Fusion reactors are still highly radioactive, I wouldn't trust them outside of centralized infrastructure.

They may not be making bunches of radioactive waste, but the fusion reaction happening makes the reactor itself radioactive... and while we can contain that easy enough, do we really trust Joe Neighbor with a radioactive car engine not to try and mess with it himself?

"Our grid power went down, so let's fire up the nuclear reactor," is indeed a horrible idea. So if that's what you mean, I wholeheartedly agree.

Going back to the radioisotope thermal-electric generator (RTG) idea, those things are "always on" by definition. You can't turn off radioactive decay and turn it on again later. So using one of those as a "backup battery" would be insane even if we ignore the power density and thermal management problems.

Edit: As for "portable" fusion reactors, such a design would be so advanced compared to anything we have today that I'd have to assume they've solved the neutron activation problem. High-energy neutrons are a bitch to contain so I wish the engineers luck on that one.

Edited by Fighteer on Mar 4th 2024 at 8:59:15 AM

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

As a baseline “always on” energy source, it can’t be beat. It isn’t dependent upon good weather and sunny days unlike solar and it can work at all times and conditions unlike wind which can have periods where it’s either not enough to generate power or too much to operate safely. Also you’d literally only have to fuel it once and not refuel it again for years.

Also it has no environmental detriment such as excess carbon or sulfur emissions unlike traditional fuels.

Yes it’ll require a bit more attention to safety so as to not irradiate at least the immediate area around the reactor but it’s far more doable than you think.

"Allah may guide their bullets, but Jesus helps those who aim down the sights."

To be clear, outside of the extremely difficult aneutronic fusion, basic fusion powerplants are still going to spit out a lot of Xrays and neutrons. A well-designed fusion reactor will have plenty of mass to stop that, but i doubt a consumer version is going to be the size of a large office building. a "Mr Fusion" to power your car will just outright kill you.

I think this is a misunderstanding. I don't mean "nuclear powered everything" as in "part of a power mix". I mean 100% nuclear power, no ifs, no buts, no exception, nothing else. It's unworkable because the baseload is only a fraction of the total load. A datacenter is constantly spinning disks up and down, and HVAC is running harder or slower based on weather and seasonal trends. It's not something a nuclear reactor can follow. It also can't spin up fast enough to deal with a sudden break in main power. So neither a full nuclear-powered datacenter nor a backup-nuclear power center is a good idea. But a datacenter plugged into the grid with a battery or conventional generator as backup can at least ensure the disks spin down to a safe state before bigger generators turn on to keep it all running.

The advantage of a big power grid is that it not only can deal with power variations by spinning up a generator somewhere, it also deals with local variance in wind and sun because it's not going to be cloudy or low-wind on a global scale. Across the USA or Europe, it's going to be windy *somewhere*. But that also means you're going to have a basic demand all the time because stuff is going to be on *somewhere*. A power mix that takes advantage of all these elements is thus ideal. i mean, that's why we've built gas powerplants even when coal was much cheaper: coal boilers are simply not capable of following minute-to-minute power changes, only hourly ones.

Edited by devak on Mar 4th 2024 at 7:39:33 PM

Batteries, in turn, have nearly instant demand response but don't actually generate power; they need to be recharged during periods of oversupply. That's why grid-scale batteries are being used around the world to replace "peaker" plants. The latter are usually powered by natural gas and designed to supply grid demand during peak hours, but they're extremely inefficient and highly polluting.

Grid batteries work by recharging when there is more power being supplied than being consumed, such as during midday when solar flux is at its maximum. Then, when everybody comes home and turns on their stoves and televisions, or when the air conditioning is at max, the batteries discharge to supply that extra demand.

Edited by Fighteer on Mar 4th 2024 at 3:50:37 PM

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

Yup.

Britain built an artificial dam for power storage (it pumps in and discharges water) and it turns on when half the nation makes a cup of tea during a sports break. Extremely unequal power demand is most of what power grid management is actually about!

An interesting facet of this is that because of the power market, storage facilities can actually make money by buying power when it's readily available and selling it when it's needed.

Would an orbital datacenter as a manned space station be a feasible idea?

Yes, but ask yourself two questions about it.

A) This is going to apply to any space based infrastructure: Why?

Building in space is hard, there is plenty of room on planets and building on them is easier, this one is not to say there is never a reason to do so, we build stuff in space today, you just need to ask "what do you get from being in space that being on a planet wont provide"

B) Relevant to a data center specificly: How are you going to cool it?

Space is a wonderful insulator and electronics produce a lot of heat, planet side ones are not only cooled by being in atmosphere but often water cooled as well...

So where is all the heat going to go?

If you can answer those your good to go.

Edited by Imca on Mar 5th 2024 at 10:52:55 PM

Given the acceleration and cost reduction of mass-to-orbit over the past few years, largely thanks to SpaceX (and China), it is no longer absurd to think that we could lift enough equipment to build an orbital data center. Communication rates aren't even that big of an issue; recent missions — plus of course Starlink — have proven that laser transmission works perfectly well, and latency to/from LEO is only a few milliseconds.

Heat dissipation, however... that is a genuine problem, and not one that is trivial to solve. Indeed, it may be the parameter that most strictly limits the viable size of spacecraft or satellites of any sort — more specifically, their size to power consumption ratio.

Other factors to consider are radiation shielding and orbital collisions. Not sure Google is eager to tell customers that they lost all their cloud data because a defunct satellite smashed into the center housing it. (Yes, I know they have redundant storage; I'm illustrating a point.)

All of these problems can be solved with sufficient engineering, but by that point the cost-benefit starts to look a little dicey. What is the notional advantage we gain by doing this?

Perhaps a more realistic scenario is distributed cloud computing — such as what Starlink is doing for Internet. Rather than one massive satellite, we can use thousands of smaller ones.

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

Also, C) how do you protect it from space weather? Computer systems don't like being hit by solar wind or cosmic rays or magnetospheric particles.

Sometimes I wonder if we need a No Space Weather trope akin to The Air Not There.

"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." - Richard Feynman

A bonus fact to complicate maters here, all energy used by a computer becomes heat.

The actual computing part of a computers operation actualy uses no energy, but due to how they function all the energy consumption rather comes from resistance in the parts... and well that all turns to heat.

There is no way around this, and it's why superconductors would be such a boon for computing.

Essentially a 700 watt computer and a 700 watt space heater heat the room the same amount, slight edge to the computer since the heater produces light...

Edited by Imca on Mar 5th 2024 at 11:05:37 PM

A very valid concern. Also has applicability right now. We are presently nearing or at a peak maximum of the 11 year sunspot cycle so there’s been a lot of geomagnetic activity the last few months.

And a number of satellite systems that have suffered errors or temporary outages as a result.

"Allah may guide their bullets, but Jesus helps those who aim down the sights."

Which is why I was thinking of putting these into MEO at least, to avoid the worst of the traffic. GEO could work, but that's still a traffic problem plus a manned station would be harder to reach all the way out there for shift changes.

And of course the radiation.

I'm sorry, you want a crewed station to house the data centers? Umm, no. Not happening.

Well, maybe once we get permanent, large-scale orbital habitation, and they'll need local data centers to keep things running. But that's not what I thought you were talking about.

MEO gets into that high-radiation environment that loves to kill electronics. Anything sent up there needs a lot of shielding, adding mass.

"It's Occam's Shuriken! If the answer is elusive, never rule out ninjas!"

At that point, why not put your data center underground in a cave on the Moon? Of course the problem would be that information takes more than one second to get from the Earth to the Moon.

Edited by minseok42 on Mar 5th 2024 at 9:17:05 AM

"Enshittification truly is how platforms die"-Cory Doctorow