(Note, I had previously written this along with the isotope separation, but wanted to give that idea a chance for discussion first.)
Another possible use for hypergravity is for training humans.
A big 2-gee facility on Earth would be expensive to build and maintain and would necessarily be small enough that you’d get large Coriolis effects. You’d be limited in size. But in orbit, you could build a large training facility that top athletes could train in, much like athletes train at high altitude. The athletes would develop denser bones, stronger muscles, and you could also reduce the oxygen concentration to get the benefits of high altitude training for lung capacity, etc. Soldiers, especially special forces, could train for months in such a facility as well.
Considering that the top 100 athletes make over $3.2 billion per year, you’ve got to think about the next 101-200 top athletes… Would they be willing to invest, say, $1-2 million so they could get in the top 100? If this proves to be a decisive advantage and is cheap enough (say $50,000 per person per week?), you could have entire teams training in large equatorial LEO (where the radiation levels are quite low, with shielding for the rest) rotating hypergravity training facilities which could also serve as orbital hotels at the lower gravity levels.
And what is a few hundred (or even thousand) supersoldiers worth per soldier? (I leave aside the idea of using the station as launch-point for special forces soldiers… There are plenty of military applications of space already.)
Each market could be multiple billion per year, and it’d intrinsically involve a real advantage to human spaceflight.
Another thing: Space tourism and settlement and even the NASA astronaut corp are for space nuts. This is one of the very few reasons why non-space-nuts would want to fly in orbit (for more than just point-to-point), and it could potentially be tens of thousands of people (athletes, soldiers, fitness nuts) in very large facilities. It’s not just because “space is neat.”
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I wouldn’t be surprised if there are forms of physical therapy that could benefit also.
Now that you’ve posted this (I saw the draft when you first posted it a few days ago before taking it back down), I’m going to do a post on why hypogravity facilities might also be interesting. I wonder what launch cost level you’d need to get down to before this was actually cheaper to do in orbit than on the ground? I like the idea a lot, but also like hypogravity because you *can’t* do that on the ground. But it’s nice having some market ideas that require actual people in space, not just shipping photons around.
A fractionally serious suggestion:
How about microgravity for treating horses with leg injuries? Here in 1 g, a horse with a broken/injured leg will put weight on the other side and develop laminitis, which frequently requires euthanasia.
Might be worth it for prized horses. Top horses may be worth $10 million or more. But launching a wounded horse to orbit sounds like a monumental task. As does finding enough room for them to prance around, and enough ECLSS and food to support such an animal. But yeah, this is a neat option for physical therapy.
“A big 2-gee facility on Earth would be expensive to build and maintain and would necessarily be small enough that youâ€™d get large Coriolis effects. Youâ€™d be limited in size. But in orbit, you could build a large training facility that top athletes could train in, much like athletes train at high altitude.”
Re: “Youâ€™d be limited in size.” On Earth.
You could build a track which was say 1 km in radius. That would be big enough and there land area [or ocean area] available to do this. Wiki:
“For example, to produce standard gravity, É¡0 = 9.80665 m/s2 with an orbital period of 15 s, the radius of rotation would have to be 56 m (184 ft), while an orbital period of 30 s would require it to be 224 m (735 ft). ”
And with radius of 1000 meters:
For 19.6 m/s/s it requires a rotation [or cycle] to be every 44.87 seconds.
So circumference is 2000 meters times pi is 6283 meter and divided 44.87 seconds
is 140 m/s [312.5 mph]
So need train which can go 315 mph and to travel at 90 degree to level surface- or riding on 90 degree bank.
So one would still have earth gravity and be adding 2 gees to it.
And believe that these force vectors would be added- or the sum of artificial gravity would not be at 90 degree to level surface- so be something like 70 degree and would greater than 2 gees, something like 2.2 gees.
But if I am wrong, one still gets the 2 gee [plus 1 gee of earth’s gravity].
Now since want large volume [or large cross section- rather than merely longer length of train car] you could encase the track so you reduce atmospheric pressure- or something like hyperloop type thing. And to reduce pressure of Earth atmosphere one would need a structure strong enough to withstand the vacuum. And this same structure strength can also act as foundation to withstand to outward gee force of train. But one could instead use streamline train which is similar as used for Maglev train, fastest Maglev train:
“The highest recorded maglev speed is 603 km/h (375 mph), achieved in Japan by JR Central’s L0 superconducting Maglev on 21 April 2015, 28 km/h (17 mph) faster than the conventional TGV wheel-rail speed record.”
Yes, it’s POSSIBLE to build such a facility on Earth, but not terribly practical. If and when launch costs drop low enough that people can get to orbit for less than $1 million, it might actually start being less hassle to build such a facility in orbit. If they get as low as folks like Bezos and Musk (and Greason?) are planning, then it really starts to look feasible.
Sure, but not half as expensive as even the simplest manned orbital facility.
2km is overkill. All it’s doing is adding velocity and complexity. At 200m diam, you’re down to 44m/s, and still only 4RPM, while still giving you up to 600m x 2m platform-width of area.
The cost of “the simplest manned orbital facility” is a function of launch cost and overall space development. If the capability exists for large crewed space platforms and cheap crewed launch, then the equation changes. Also, at 200m, you’ll still be experiencing significant Coriolis. Might work for some purposes, but too small for comfort. Since you’ll need to be living in such a facility for weeks or months and you’ll have high net worth individuals doing so, you’ll need a facility large enough for extensive comforts (other than the punishing 1.5-2gees 🙂 ). If you’re building a huge facility, spinning at high speeds, putting it in a vacuum to reduce the otherwise huge energy costs (and wind, etc) like hyperloop, then it seems feasible that in a world with, say, sub-$100k per person launch costs, you could make a good case for just doing it in orbit.
I mean, today, with the ~$20 million per person launch costs, I see no way to make a good business case vs an Earth-based facility, but in a world with a factor of 100-1000x less cost-to-orbit (and possibly more experience with orbital manufacturing an off-world resource gathering) and with an already-existing mass orbital tourism market, I can definitely see it make sense.
(Additionally, there are some other synergies for basing special ops teams in a constellation of orbital stations that I didn’t really want to get into.)
Coriolis issues have been exaggerated over the years, due to early work which didn’t properly test adaptation. Recent work suggest most people should be able to adapt up to 10RPM. So 4RPM should be fairly simple. (Given what top end athletes put up with, this will be fairly minor.)
Thread hijacking, but I really think such a ground facility would be useful for NASA. I suspect that a period of high-g before a mission would reduce the effects of micro-gravity. And higher-g after a mission would speed up recovery from long-duration micro-g.
Also testing at points between 1.5 – 3g would give us the shape of the health-curve, which probably would allow us to project down into the sub-1g range. Gives us an idea what would be the minimum beneficial size for a spin-g habitat in space.
If 5-7t launches drop to less than $1m (7-10 people in a capsule at less than $100k per), you really won’t need to invent such novelties to find payloads.
The issue is getting there from here.
Using drop-ships from a small number of orbital facilities makes them too predictable. You are also waiting on the orbital inclination to align with the target.
However, if orbital launch costs are sub-million and routine and safe enough for sports-medicine/etc, then using the first stage as a point-to-point sub-orbital ferry would be within reach of especially a military budget. That means you can launch on demand, maximum 90 minutes flight time anywhere in the world, and minimal early warning for any target that doesn’t have an ICBM-early-warning satellite network.
“Coriolis issues have been exaggerated over the years, due to early work which didnâ€™t properly test adaptation. Recent work suggest most people should be able to adapt up to 10RPM. So 4RPM should be fairly simple. (Given what top end athletes put up with, this will be fairly minor.)”
I agree that astronaut adaptation to Coriolis is likely to work well, and that problems associated with that are hugely exaggerated (as is the case with so many things in this field), but if you’re developing a training facility, you don’t WANT your subjects to adapt. Because that means having to re-adapt when they land. Additionally, while I think astronauts are plenty tough enough to cope with the symptoms of nausea that would occur in the initial stages of adaptation (and re-adaptation), it would certainly make the whole idea much less appealing to the high net worth individuals you’re trying to market this to.
And I do think costs can get down that low. I don’t think this market alone will bring that about. But there needs to be a bunch of multi-billion-dollar markets to make the investments needed to get there look attractive. Just adding to that list.
And your point about point-to-point travel is quite true. The idea wouldn’t be to wait for your orbital inclination to line up, but to have several such facilities in orbit, with craft tether-launched for the rotating space station given 1km/s initial impulse, plus a small winged (but vertical-landing) reentry vehicle capable of large cross-range and high maneuverability as a landing craft. But anyway, this is just one idea among many. Point-to-point is at least as attractive, but you wouldn’t want a large SSTO vehicle as it represents too large of a target for the enemy (even a not-very-sophisticated one). But militarization of low Earth orbit in general sounds like a bad idea. It’d be a very bad idea if you’re attempting to target large states (capable of destroying your orbital facilities), less of a bad idea if you’re targeting non-state-actors.
–Chris Stelter says:
April 17, 2016 at 10:42 am
Yes, itâ€™s POSSIBLE to build such a facility on Earth, but not terribly practical. If and when launch costs drop low enough that people can get to orbit for less than $1 million, it might actually start being less hassle to build such a facility in orbit. If they get as low as folks like Bezos and Musk (and Greason?) are planning, then it really starts to look feasible.—
Well if you have settlements on Mars, it should be cheap to leave Mars, also.
The premise of being able to commercially mine water on the Moon is based upon
the payload cost of lunar surface to lunar orbit being similar to launch cost from Earth surface to Earth orbit. Or about $2000 per lb to orbit.
With the Moon and within couple decades the main cost is lunar rocket fuel- a 1000 times more expensive as compared to price rocket fuel on Earth, but the Moon can reach about parity because it has less of a gravity well or one needs around 1/10th of the rocket fuel.
With the Moon within a century one could have lunar rocket fuel being around same cost as Earth rocket fuel- though after a century with the Moon one probably not mainly using rocket fuel to leave the Moon. Or eventually cost to lunar orbit could about 10 cent per lb- as it’s lack of atmosphere allows high velocity at lunar surface- leaving the Moon is like Earth subway ticket.
With Mars settlement one should able to get rocket fuel at parity with lunar rocket fuel- when lunar rocket fuel about $1000 per lb, Mars rocket fuel would about $1000 per lb and reaching rough parity with Earth to present orbit costs.
Were Earth cost to orbit to lower to $100 per lb this results in lower cost to leave the Moon and Mars- and given enough time both Mars and Moon will have lower costs to orbit as compare to Earth- even if rocket fuel on either is 10 times higher than Earth rocket fuel.
But even in this situation of cheap cost of getting to orbit one could have 1 or 2 gee facilities on Mars and Moon surface. Or the low gravity of Moon and Mars could be non problem in terms living there for long periods.
Of course doesn’t address these problems in terms of exploring these places so that future settlements are possible.
Pista Centrifuga for training runners with hypergravity has been available for years, but has not become mainstream. Perhaps there are problems with excess gravity, or perhaps it is easier to don a weighted pack. -MBM
You may enjoy reading this:
Great Mambo Chicken And The Transhuman Condition: Science Slightly Over The Edge.
by Ed Regis (Author).
For the relevance to this topic, see this review:
REVIEW 14 March 1992
Review: Spin a chicken
By WENDY GROSSMAN