"Terraforming" the Asteroid Belt

Tom Kalbfus · 2014-11-04 16:31:31

Antius wrote:

RobertDyck wrote:
I wouldn't build a habitat as a centrifuge on any world. If you need that, you can't step outside to prospect or mine minerals. Build space habitats as a giant centrifuge: O'Neill cylinder, Stanford torus, Bernal sphere. They can mine asteroids for materials. But not on a world. Not a planet or dwarf planet. My hope is that gravity is sufficient to prevent microgravity effects on the human body. So 90% gravity on Venus, 38% on Mars, 1/6 on Luna, 1/7 on Ganymede, 1/8 on Callisto.
But you mentioned Ceres. That's awkward. Surface gravity is so weak that it's probably not sufficient to avoid microgravity effects. According to Wikipedia, surface gravity is 0.029 g. Also not enough to sustain an atmosphere. But enough to form a round body, which classifies it as a dwarf planet. Material will be differentiated. It's believed that metal asteroids formed in the core of an asteroid with sufficient gravity to differentiate material, and sufficient heat to melt metal. By today's classification, that would be a dwarf planet. So at some point in the early formation of our solar system, a collision broke apart a dwarf planet. Metal asteroids today are the core of that dwarf planet. So Ceres is what that other planet would have looked like. And that means Ceres most likely has a iron core. But Wikipedia says surface is similar to a C-type asteroids, so carbonaceous chondrite. At least what we can see with telescopes. So an interesting suite of resources.
Eh. I guess a centrifuge hab would work. Good luck with that.
If gravity is too weak to maintain healthy bone mass, one solution may be to put people into short rotation centrifuges for 1 hour a day. That would be relatively easy from an engineering standpoint and the literature I have read suggests that it mitigates bone demineralisation resulting from bedrest. And bedrest is a good simulation of microgravity so far as the human body is concerned.

Ceres has 5% gravity, that is nearly weightless. As a counter argument, how would you like to spend 23 hours in bed every day, and on the 24th hour you get up and walk around, is that going to be enough? I think Ceres has low enough gravity that you can treat it as zero g for most intents and purposes. Walking would be very difficult, unless you do so very slowly. Most people would get around by leaping and jumping. At 5% Earth' gravity, the acceleration is 50 centimeters per second squared.

Terraformer · 2014-11-04 16:38:46

It's 2.7%, not 5%. Perhaps magnetised boots would provide enough stickiness to walk normally, and save the leaping for outside (which will still be inside, given paraterraforming).

I don't think there's going to be a problem with going for a run in a centrifuge every day...

Void · 2014-11-05 11:34:09

I would handle the outside with a upgrade of this:
http://en.wikipedia.org/wiki/John_Lethbridge

I hope my math is correct 150 (68.0389 kg) pound person could have a suit of a weight of 5555.55 LB ( 2519.96 kg). That could include spiked wheels to try to deal with inertia.

I would have the human in a subsuit under the frame. The subsuit would be large enough to allow body functions without unsuiting as I have spoken of in other threads. This would also be good, because you could incorporate significant solar cells, and batteries (Or other storage method).

Tom Kalbfus · 2014-11-06 05:02:46

Terraformer wrote:

It's 2.7%, not 5%. Perhaps magnetised boots would provide enough stickiness to walk normally, and save the leaping for outside (which will still be inside, given paraterraforming).
I don't think there's going to be a problem with going for a run in a centrifuge every day...

You ever try to pick up a rock with a magnet? I don't think magnetized boots would be of much help on the surface of Ceres Much of Ceres is not made of material that is attracted to magnets.

Terraformer · 2014-11-06 06:38:02

Tom, you weary me with your inability to fully read posts before replying to them.

Void · 2014-11-07 09:07:42

What if you cut tunnels with a height of 370 feet and a width of 5 to 10 feet?

Surface
--------------------------------------------------------------------

__ 370 feet
| |
| |
| |
| |
| |
| | Ice
| |
| |
| |
| |
| |
| |
|_| 0 feet

I wonder what synthetic gravity would be like in a hamster wheel in one of these? Say 1/3 gee +/- 2.7%? over the travel of the wheel?

A bit like riding in an elevator?

And the tunnels themselves might not need supports, maybe just some bracing at the top.

Looking from the top view, you might have layouts like this:

Main _______________________________________________
| | \
a b \
\_____________________________________ and whatever, as many such tunnels as you would want.

'a' might be a place for a centrifuge, 'b' might be where a tall building that actually has an airlock on the surface, but where the building was mostly embedded in the ice.

Granted you would want to have some type of vacuum proof covering over the ice walls.

Antius · 2014-11-07 10:19:08

Rotating habitats or at least rotating buildings would appear to be a workable solution.

It is clearly a less efficient solution than a free space O'Neil type habitat, as you would need to mount your habitat on bearings and would need continuous electric power input to an electric motor in order to overcome friction and air resistance. Still, in low gee, air or magnetic bearings would be easier to engineer. The bigger the building and the slower the rotation rate, the lower the effective air resistance per unit volume. Or if your entire hab is rotating in a vacuum, air resistance is obviously zero. Using bearings and an electric motor obviously pushes up the cost, but it does not make the option unworkable.

For low mass asteroids you could probably rotate the hab without any consideration of the parent body's gravitational effects on the interior, i.e. in any direction you wish. For larger bodies such as Ceres, a carousel approach might work better, where effective gravity is the vector product of real and rotational gravity. Otherwise effective gravity will have a sinusoidal variation, leading to motion sickness.

Void · 2014-11-07 11:23:53

Its nice that there would be choices.

As for the odd shaped tunnels, the low gravitation on Ceres should make it easy to have things all over the walls, such as a factory process line, and people could either leap up, or pull themselves up on a rope or ladders. Perhaps no need or use for stairs. Maybe just a pneumatic jet pack to fly about inside of the tall tunnel spaces.

Tom Kalbfus · 2014-11-08 06:57:22

Humans weren't built for living in space, you can't expect them to adapt as if they had always lived there! I think you can place an O'Neill cylinder on its end and rotate it on a track placed on the Surface of Ceres. The thin is, Ceres would help stabilize the cylinder, preventing it from going in a roll to flipping end over end. The longer you make an O'Neill cylinder the more likely it is to go out of balance and flip end over end, but not if you anchor it to the surface of Ceres! Would you like an O'Neill cylinder that is 10 km wide and 1000 km long? You can have a river flowing down each valley towards the surface of Ceres.

Last edited by Tom Kalbfus (2014-11-08 07:01:53)

Void · 2014-11-11 09:17:47

That's an interesting idea. One reason I am interested in Ceres, is that although many star systems may not have good worlds to inhabit, it may be that an object similar to Ceres could be found. Having adapted to Ceres here, then you would have a method for habitation there. A smaller cold object would be much easier to access than a large cold one.

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#26 2014-11-04 16:31:31

Re: "Terraforming" the Asteroid Belt

#27 2014-11-04 16:38:46

Re: "Terraforming" the Asteroid Belt

#28 2014-11-05 11:34:09

Re: "Terraforming" the Asteroid Belt

#29 2014-11-06 05:02:46

Re: "Terraforming" the Asteroid Belt

#30 2014-11-06 06:38:02

Re: "Terraforming" the Asteroid Belt

#31 2014-11-07 09:07:42

Re: "Terraforming" the Asteroid Belt

#32 2014-11-07 10:19:08

Re: "Terraforming" the Asteroid Belt

#33 2014-11-07 11:23:53

Re: "Terraforming" the Asteroid Belt

#34 2014-11-08 06:57:22

Re: "Terraforming" the Asteroid Belt

#35 2014-11-11 09:17:47

Re: "Terraforming" the Asteroid Belt

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