New Space Settlement image

> From: Marcel Williams [mailto:newpapyrus@...]
>
> MW: If your talkin' luxury liner then your talkin'
> about a big space station. But if your talking about
> O'neill type space colonies then at mininimum these
> would have to be at least 2 kilometers in diameter
> just to make sure that 99.9% of the people who inhabit
> themwon't feel nausea. Medical research back in the
> 1970s showed that rotation rates higher than 1rpm for
> a 1G simulated gravity were not healthy-- so you have
> to have a structure with a diameter of at least 2
> kilometers.

While agreeing with you on the distinction between a station (even a
luxurious one) and a habitat, I must comment that there is some disagreement
on this issue of spin rate. There are other studies which suggest that 2-3
RPMs might be acceptable to the biggest majority of people. O'Neill felt
that his Bernal Sphere, at 2 RPMs, was a reasonable compromise. The 1 RPM
upper limit was adhered to in the NASA-Ames study, though. There, a
diameter of 1.1 mile was assumed.

Another variable in this is if it should turn out that some gravity lower
than 1 G is acceptable. This might result in smaller structures for a given
spin rate, or lower spin rates for a given structure. In other words, we
might see something as small as a Bernal Sphere, but it may only rotate at 1
RPM to give 1/2 of a G at the equator.

> I cover the entire surface of a
> cylindrical cosmodrome with shielding (soil and
> water)-- even the window area (water about 5 meters
> deep).

2 meters would probably be sufficient. I think that's what Marshal Savage
assumes for his water shield.

> Of course, I prefer a cosmodrome about 30
> kilometers in diameter and about 100 kilometers long.

I think you would be beyond current material strengths there. O'Neill
calculated the maximum size possible as 19 km diameter for a titanium
sphere. But that would be no slouch; providing around two hundred square
kilometers of land.

> Only the mass production of structures that size will
> ever attract people from Earth to live their forever,
> IMO.

I agree with your thinking. Many Europeans might be comfortable in a Bernal
Sphere, but most Americans and others used to a little bit more distance
between neighbors probably wouldn't settle for anything less than an O'Neill
Cylinder.

Regards,

Mike Combs

> From: Marcel Williams [
mailto:newpapyrus@...
]
>
> MW: If your talkin' luxury liner then your talkin'
> about a big space station. But if your talking about
> O'neill type space colonies then at mininimum these
> would have to be at least 2 kilometers in diameter
> just to make sure that 99.9% of the people who inhabit
> themwon't feel nausea. Medical research back in the
> 1970s showed that rotation rates higher than 1rpm for
a 1G simulated gravity were not healthy-- so you have
> to have a structure with a diameter of at least 2
> kilometers.
While agreeing with you on the distinction between a station (even a luxurious one) and a habitat, I must comment that there is some disagreement on this issue of spin rate. There are other studies which suggest that 2-3 RPMs might be acceptable to the biggest majority of people. O'Neill felt that his Bernal Sphere, at 2 RPMs, was a reasonable compromise. The 1 RPM upper limit was adhered to in the NASA-Ames study, though. There, a diameter of 1.1 mile was assumed.
Another variable in this is if it should turn out that some gravity lower than 1 G is acceptable. This might result in smaller structures for a given spin rate, or lower spin rates for a given structure. In other words, we might see something as small as a Bernal Sphere, but it may only rotate at 1 RPM to give 1/2 of a G at the equator.
> I cover the entire surface of a
> cylindrical cosmodrome with shielding (soil and
> water)-- even the window area (water about 5 meters
> deep).
2 meters would probably be sufficient. I think that's what Marshal Savage assumes for his water shield.
> Of course, I prefer a cosmodrome about 30
> kilometers in diameter and about 100 kilometers long.
I think you would be beyond current material strengths there. O'Neill calculated the maximum size possible as 19 km diameter for a titanium sphere. But that would be no slouch; providing around two hundred square kilometers of land.
> Only the mass production of structures that size will
> ever attract people from Earth to live their forever,
> IMO.
I agree with your thinking. Many Europeans might be comfortable in a Bernal Sphere, but most Americans and others used to a little bit more distance between neighbors probably wouldn't settle for anything less than an O'Neill Cylinder.
Regards,
Mike Combs