Artificial Gravity Breakthrough what-if

[Coyote]

Let's suppose that in the very near future, some sort of miracle breakthrough is made that allows us to generate a field of artificial gravity. The machinery required to do this, as one would expect, would be bulky, expensive, and power-hungry. Each gravity plate that a person would walk on rests on a device about the size and weight of a refrigerator, and requires a constant feed from a high-energy power source-- easy requiring a nuclear reactor to be able to run just a dozen or so.

Space exploration agencies decide that such a power-hungry, bulky device won't be practical for most spaceships, although it does make long-term manned missions more practical. But Earth-Orbit-Moon missions, still done by the planned Ares/Orion vehicles, just can't afford the payload and don't really need it for such "short" trips.

So the grav well generators are planned for the ISS, a manned mission to Mars command ship, and for a Moon base.

So I'm wondering, where would be the best, and most likely places, to put these gravity generators? Whole ships and stations can't be outfitted with them; it's too expensive and impractical. The costs work out to one gravity well generator for every member of a crew. With that as a limitation, where should engineers plan to put these generators where they'd do the most use?

My first thought was to have the generators be where the crewer sleeps-- that's at least 5-8 hours in a near-Earth gravity. That's a few good hours in gravity that doesn't take the crewman away from his or her mission. But on further thought, sleeping in gravity may be good, but it doesn't necessarily build bone & muscle mass, and may not prevent the deterioration.

So my second thought was to have the generator be the crewman's workout area, a place for daily physical fitness. But again, you have a crewer sleeping for a few hours, then exercising for, what, maybe 2 hours at most? During which time they aren't doing anything else productive for all the expense to get them there. And despite orders, exercise time is something that is likely to be cut into by mission demands or just after a long day. Not to mention you've shipped a heavy, expensive gravity unit for a couple hours a day worth of use.

Have the gravity well be at the crew workstations? Maybe, but workstations shift, and sometimes a crewer may need zero or low gravity for their job.

The best compromise I could think of so far was to have one grav well under a set of bunk beds, and then have four people 'hot-bunk' on them: four people can sleep in gravity generated by one well; while the other three wells allocated per the rest of them are put together in a group room for meals and breaks, or maybe a gym.

Is there a better way to allocate the gravity wells to maximize people's exposure without cutting into productivity, while maintaining health and morale as best as possible and justifying the expense/power?

[erik_t]

They wouldn't be anywhere in space, because you'd have to dump all that power as heat sooner or later.

[Darth Wong]

Let's suppose that in the very near future, some sort of miracle breakthrough is made that allows us to generate a field of artificial gravity. The machinery required to do this, as one would expect, would be bulky, expensive, and power-hungry. Each gravity plate that a person would walk on rests on a device about the size and weight of a refrigerator, and requires a constant feed from a high-energy power source-- easy requiring a nuclear reactor to be able to run just a dozen or so.

How large of a reactor? A tiny little 10kW unit or a 1400MW behemoth? It's really pretty vague to say "nuclear reactor" for power consumption requirements.

[Broomstick]

Astronauts are already required to perform mandatory exercise on long space missions - it at least slows deterioration even if it doesn't stop it. So park the grav plates under the workout space to improve upon what is already required.

That sort of thing isn't required on a 1 week shuttle mission, but it is for the long-term space station stays. You can't work a human being 16 hours a day with absolutely no down/break/rest time for more than a very short period of time.

[Coyote]

How large of a reactor? A tiny little 10kW unit or a 1400MW behemoth? It's really pretty vague to say "nuclear reactor" for power consumption requirements.

I keep forgetting how small they can make those things now. Let's say at least a ten megawatt reactor to power about a dozen.

[Darth Wong]

So each unit must dissipate nearly a megawatt of power? I'd have to say that you wouldn't want to put it in an exercise area, then. The heat dissipation would cook everyone.

PS. Let's try to put this in some sort of perspective you can subjectively appreciate. You know those 1500W space heaters you buy at Home Depot? Imagine putting more than five hundred of them together in a huge block, cranking them all to full power, and then channeling all that heat so it comes out of a space no bigger than your average fridge.

[Coyote]

That would hurt.

The power source is not so important as the ability to maximize the grav units; I'm just trying to think of some sort of power source that is not easily portable.

I was thinking that the grav units themselves would be hooked into a ship or station's power source, whatever it would be, and run without too much heat buildup of their own. So the nuclear reactor (or whatever the power source was) was a ship's engine, or a base/station powerplant, and the grav units fed from it like large plug-in appliances. Not that each one of these things would, individually, need a 10MW nuclear plant hooked in individually.

[Ariphaos]

I can't see how that would possibly be more efficient than just having a rotating section.

[Coyote]

I can't see how that would possibly be more efficient than just having a rotating section.

For a moon base, that won't work so well.

For ships, it is less moving parts and less mass. Rotation is all well and good but the rotating sections have to have a wide diameter, IIRC, to get the proper desired advantage out of the spin. There's a proper term for it, which I can't remember, but a spinning section where your feet get the benefit of the gravity but your upper torso and head are still effectively in null-gee. The amount of superstructure needed --and the more superstructure, the more torque, the more power needed to spin it, etc-- a dozen units the size of refrigerators with little or no moving parts is a downright bargain in comparison.

[Hawkwings]

If you're on the moon, just use the ground as a heat sink.

As for a rotating section, well, once you get it started, it only needs occasional nudges to keep it going, right?

[Starglider]

Rather than power requirements it would be more sensible to make these things ludicrously expensive, or perhaps require a bulky heavy particle accelerator to provide a specialised kind of excitation energy.

[Darth Raptor]

So it's wildly impractical, as opposed to impossible? The deleterious effects of low-to-no gravity is a problem that is best addressed with a medical approach-- drugs and/or gene therapy. I can only see this being used for the kind of fabrication that needs to be done in gravity, and only when it's not practicable to build rotating sections.

[Starglider]

The deleterious effects of low-to-no gravity is a problem that is best addressed with a medical approach-- drugs and/or gene therapy.

For exercise purposes it is possible to simply apply direct pressure with a harness, or for a more high-tech solution an exoskeleton programmed to simulate body weight. I'm not sure if that helps with bone loss though.

[RedImperator]

The problem with this is that you're not going to save mass at all on a spaceship with these, even compared to an elaborate internal centrifuge or something to simulate gravity. Adding the mass of a refrigerator for every plate is non-trivial, and on top of that you're going to need extra reactor capacity to operate them and a fuckload extra cooling equipment and radiator area. The moon is another matter, since you have a heatsink, no mass limits, and no practical way to simulate gravity, but even then, the cost of getting all this equipment to the moon is going to be...ahem...astronomical.

[The Duchess of Zeon]

Shouldn't this thing actually be able to be used as a repulsorlift more or less? It sounds like it magically increases the effective mass of an object near it, so couldn't it be at the very least integrated into the accelerator for an ion drive, for example, to vastly reduce fuel requirements, possibly to the point of outweighing the weight cost of the reactor onboard? Since you can make your exhaust stream of a much heavier mass than it actually is when it's being stored. Considering it can go from microgravity to 1 g, if you could devote 10 tons to a reactor to power the assembly, you might be able to slash the fuel requirements from a thousand tons to one ton of fuel for the same mission, and then you've just saved 989 tons on the weight--it would be sort of, for the layman, like supercharging an engine.

This of course assumes that you can't just hit the reverse button and actually use it as a repulsorlift.