New paper suggests a much easier path to space settlement

That's awesome, those dimensions are on the same scale as the ISS, for
instance.

Also, I've thought that by now we should have tiny rotating habitats at
partial gravity - at Mars and Lunar gravity, for instance - rotating at
less RPMs than we would need for 1g. Part of the official justification for
things like the ISS for instance is "zero g research", but we have decades
of research on zero g and the general conclusion is "it sucks big time". On
the other hand, we have basically no research on the effects of partial
gravities, and it would be much cheaper to simply create a rotating habitat
at LEO in order to simulate them than to actually send people to the Moon
and Mars.

On Wed, May 13, 2015 at 2:03 PM, Al Globus alglobus@...
[spacesettlers] wrote:

>
> "Space Settlement Population Rotation Tolerance," Al Globus and Theodore
> Hall, preprint, May 2015. This paper reviews the literature to find that
> space settlement residents and visitors can tolerate at least four, and
> proabaly six, rotations per minute to achieve 1g of artificial gravity.
> This means settlements can be radically smaller, and thus easier to build,
> than previously believed. Combined with a second paper on radiation
> shielding which is being revised, the first space settlements can be two
> orders of magnitude less massive and much closer than previous designs
> making launch from Earth practical.
>
> For full text see http://space.alglobus.net/papers/RotationPaper.pdf
>
> Full abstract
>
> To avoid a number of very negative health effects due to micro-g,
> free-space settlements may be rotated to provide 1g of artificial gravity.
> Since the NASA/Stanford space settlement studies of the 1970s the
> settlement design community has assumed that rotation rates must be no more
> than 1-2 rpm to avoid motion sickness. To achieve 1g, this rotation rate
> implies a settlement radius of approximately 225-895 m, which is much
> larger than any existing satellite. In this paper we examine the literature
> and find good reason to believe that much higher rotation rates may be
> acceptable to residents and visitors alike, significantly reducing the
> minimum size of settlements and thus the difficulty of building them. We
> find that rotation rates of up to 4 rpm, corresponding to a 56 m radius,
> should be acceptable, although visitors may require some training and
> perhaps a day or so of adaptation for those particularly susceptible to
> motion sickness. A rotation rate of up to 6 rpm (25 m radius) should be
> acceptable for residents but visitors will almost certainly need training
> and/or a few days to adapt. While higher rotation rates (up to 10 rpm) may
> be acceptable with training, such small structures are not suitable for
> permanent residence (9 m radius at 10 rpm). With some caveats due to the
> quality of the available data, it appears that the lower limit of space
> settlement size is not determined by human response to rotation rate but
> rather by other factors. This means that the effort necessary to build the
> first space settlements may be significantly less than previously believed,
> simply because they can be much smaller than heretofore expected.
>
> If you want off this list, just reply to this email and ask out.
>

Also, I've thought that by now we should have tiny rotating habitats at partial gravity - at Mars and Lunar gravity, for instance - rotating at less RPMs than we would need for 1g. Part of the official justification for things like the ISS for instance is "zero g research", but we have decades of research on zero g and the general conclusion is "it sucks big time". On the other hand, we have basically no research on the effects of partial gravities, and it would be much cheaper to simply create a rotating habitat at LEO in order to simulate them than to actually send people to the Moon and Mars.
On Wed, May 13, 2015 at 2:03 PM, Al Globus
alglobus@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

"Space Settlement Population Rotation Tolerance," Al Globus and Theodore Hall, preprint, May 2015. This paper reviews the literature to find that space settlement residents and visitors can tolerate at least four, and proabaly six, rotations per minute to achieve 1g of artificial gravity. This means settlements can be radically smaller, and thus easier to build, than previously believed. Combined with a second paper on radiation shielding which is being revised, the first space settlements can be two orders of magnitude less massive and much closer than previous designs making launch from Earth practical.
For full text see
http://space.alglobus.net/papers/RotationPaper.pdf
Full abstract
To avoid a number of very negative health effects due to micro-g, free-space settlements may be rotated to provide 1g of artificial gravity. Since the NASA/Stanford space settlement studies of the 1970s the settlement design community has assumed that rotation rates must be no more than 1-2 rpm to avoid motion sickness. To achieve 1g, this rotation rate implies a settlement radius of approximately 225-895 m, which is much larger than any existing satellite. In this paper we examine the literature and find good reason to believe that much higher rotation rates may be acceptable to residents and visitors alike, significantly reducing the minimum size of settlements and thus the difficulty of building them. We find that rotation rates of up to 4 rpm, corresponding to a 56 m radius, should be acceptable, although visitors may require some training and perhaps a day or so of adaptation for those particularly susceptible to motion sickness. A rotation rate of up to 6 rpm (25 m radius) should be acceptable for residents but visitors will almost certainly need training and/or a few days to adapt. While higher rotation rates (up to 10 rpm) may be acceptable with training, such small structures are not suitable for permanent residence (9 m radius at 10 rpm). With some caveats due to the quality of the available data, it appears that the lower limit of space settlement size is not determined by human response to rotation rate but rather by other factors. This means that the effort necessary to build the first space settlements may be significantly less than previously believed, simply because they can be much smaller than heretofore expected.
If you want off this list, just reply to this email and ask out.