"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.
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.

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.

The *g* thresholds at which these effects occur depend on the training, age
and fitness of the individual. An un-trained individual not used to
the *g*-straining
maneuver, can black out between 4 and 6 *g*, particularly if this is pulled
suddenly. Roller coasters typically do not expose the occupants to much
more than about 3 g. A hard slap on the face may impose hundreds of g-s
locally but may not produce any obvious damage: a constant 15 g-s for a
minute, however, may be deadly. A trained, fit individual wearing a *g*
suit and practising the straining maneuver, can, with some difficulty,
sustain up to 9*g* without loss of consciousness.
http://en.wikipedia.org/wiki/High-G_training

We could get some idea of the problems, by mounting a small, hinged (to
provide banking), residence on a centrifuge and testing on Earth.

Regards,
Selvaraj

On 13 May 2015 at 22:33, Al Globus alglobus@... [spacesettlers] <
spacesettlers@yahoogroups.com> 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.
>

g
thresholds at which these effects occur depend on the training, age and fitness of the individual. An un-trained individual not used to the
g
-straining maneuver, can black out between 4 and 6
g
, particularly if this is pulled suddenly. Roller coasters typically do not expose the occupants to much more than about 3 g. A hard slap on the face may impose hundreds of g-s locally but may not produce any obvious damage: a constant 15 g-s for a minute, however, may be deadly. A trained, fit individual wearing a
g
suit and practising the straining maneuver, can, with some difficulty, sustain up to 9
g
without loss of consciousness.
http://en.wikipedia.org/wiki/High-G_training
We could get some idea of the problems, by mounting a small, hinged (to provide banking), residence on a centrifuge and testing on Earth.
Regards,
Selvaraj
On 13 May 2015 at 22:33, 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.

No, any problem is in the 0-1g range. You can't go below 1g on Earth.

Incidentally, those 4-6g ranges are mostly for vertical g-forces. When
you're lying flat on your back wrt to the g-force, over 10g is survivable
even for several minutes, although uncomfortable.

On 14 May 2015 at 17:16, sraj sraj99@... [spacesettlers] <
spacesettlers@yahoogroups.com> wrote:

>
> The *g* thresholds at which these effects occur depend on the training,
> age and fitness of the individual. An un-trained individual not used to the
> *g*-straining maneuver, can black out between 4 and 6 *g*, particularly
> if this is pulled suddenly. Roller coasters typically do not expose the
> occupants to much more than about 3 g. A hard slap on the face may impose
> hundreds of g-s locally but may not produce any obvious damage: a constant
> 15 g-s for a minute, however, may be deadly. A trained, fit individual
> wearing a *g* suit and practising the straining maneuver, can, with some
> difficulty, sustain up to 9*g* without loss of consciousness.
> http://en.wikipedia.org/wiki/High-G_training
>
> -------------
>
> We could get some idea of the problems, by mounting a small, hinged (to
> provide banking), residence on a centrifuge and testing on Earth.
>
> Regards,
> Selvaraj
>
> On 13 May 2015 at 22:33, Al Globus alglobus@... [spacesettlers] <
> spacesettlers@yahoogroups.com> 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.
>>
>

--
-Ian Woollard

Incidentally, those 4-6g ranges are mostly for vertical g-forces. When you're lying flat on your back wrt to the g-force, over 10g is survivable even for several minutes, although uncomfortable.
On 14 May 2015 at 17:16, sraj
sraj99@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>
The
g
thresholds at which these effects occur depend on the training, age and fitness of the individual. An un-trained individual not used to the
g
-straining maneuver, can black out between 4 and 6
g
, particularly if this is pulled suddenly. Roller coasters typically do not expose the occupants to much more than about 3 g. A hard slap on the face may impose hundreds of g-s locally but may not produce any obvious damage: a constant 15 g-s for a minute, however, may be deadly. A trained, fit individual wearing a
g
suit and practising the straining maneuver, can, with some difficulty, sustain up to 9
g
without loss of consciousness.
http://en.wikipedia.org/wiki/High-G_training
We could get some idea of the problems, by mounting a small, hinged (to provide banking), residence on a centrifuge and testing on Earth.
Regards,
Selvaraj
On 13 May 2015 at 22:33, 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.
-Ian Woollard

True. Yet by rotating the centrifuge in the 0 - 1g range (lateral
component), we stand to get some idea of the problems if any we are going
to face. If no one has any problem over say 10 days, we would have crossed
a primary hurdle.

Regards,
Selvaraj

On 14 May 2015 at 22:39, Ian Woollard ian.woollard@...
[spacesettlers] wrote:

>
> No, any problem is in the 0-1g range. You can't go below 1g on Earth.
>
> Incidentally, those 4-6g ranges are mostly for vertical g-forces. When
> you're lying flat on your back wrt to the g-force, over 10g is survivable
> even for several minutes, although uncomfortable.
>
> On 14 May 2015 at 17:16, sraj sraj99@... [spacesettlers] <
> spacesettlers@yahoogroups.com> wrote:
>
>>
>>
>> The *g* thresholds at which these effects occur depend on the training,
>> age and fitness of the individual. An un-trained individual not used to the
>> *g*-straining maneuver, can black out between 4 and 6 *g*, particularly
>> if this is pulled suddenly. Roller coasters typically do not expose the
>> occupants to much more than about 3 g. A hard slap on the face may impose
>> hundreds of g-s locally but may not produce any obvious damage: a constant
>> 15 g-s for a minute, however, may be deadly. A trained, fit individual
>> wearing a *g* suit and practising the straining maneuver, can, with some
>> difficulty, sustain up to 9*g* without loss of consciousness.
>> http://en.wikipedia.org/wiki/High-G_training
>>
>> -------------
>>
>> We could get some idea of the problems, by mounting a small, hinged (to
>> provide banking), residence on a centrifuge and testing on Earth.
>>
>> Regards,
>> Selvaraj
>>
>> On 13 May 2015 at 22:33, Al Globus alglobus@... [spacesettlers] <
>> spacesettlers@yahoogroups.com> 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.
>>>
>>
>>
>>
>>
>
> --
> -Ian Woollard
>

Regards,
Selvaraj
On 14 May 2015 at 22:39, Ian Woollard
ian.woollard@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

No, any problem is in the 0-1g range. You can't go below 1g on Earth.
Incidentally, those 4-6g ranges are mostly for vertical g-forces. When you're lying flat on your back wrt to the g-force, over 10g is survivable even for several minutes, although uncomfortable.
On 14 May 2015 at 17:16, sraj
sraj99@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>
The
g
thresholds at which these effects occur depend on the training, age and fitness of the individual. An un-trained individual not used to the
g
-straining maneuver, can black out between 4 and 6
g
, particularly if this is pulled suddenly. Roller coasters typically do not expose the occupants to much more than about 3 g. A hard slap on the face may impose hundreds of g-s locally but may not produce any obvious damage: a constant 15 g-s for a minute, however, may be deadly. A trained, fit individual wearing a
g
suit and practising the straining maneuver, can, with some difficulty, sustain up to 9
g
without loss of consciousness.
http://en.wikipedia.org/wiki/High-G_training
We could get some idea of the problems, by mounting a small, hinged (to provide banking), residence on a centrifuge and testing on Earth.
Regards,
Selvaraj
On 13 May 2015 at 22:33, 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.
-Ian Woollard

That would just add a lateral component to the 1g vector pointing down
below, and in the end the resulting vector would be > 1g.

For instance if you put 0.5 g on the centrifugue the module of the
resulting vector will be sqrt(1g2+0.5g2)=1.12g

That's why this kind of experiment on partial gravity can *only* be done
either in space or in the actual surface of a smaller planetary body.

On Fri, May 15, 2015 at 1:33 AM, sraj sraj99@gmail.com [spacesettlers] <
spacesettlers@yahoogroups.com> wrote:

>
> True. Yet by rotating the centrifuge in the 0 - 1g range (lateral
> component), we stand to get some idea of the problems if any we are going
> to face. If no one has any problem over say 10 days, we would have crossed
> a primary hurdle.
>
> Regards,
> Selvaraj
>
> On 14 May 2015 at 22:39, Ian Woollard ian.woollard@...
> [spacesettlers] wrote:
>
>>
>>
>> No, any problem is in the 0-1g range. You can't go below 1g on Earth.
>>
>> Incidentally, those 4-6g ranges are mostly for vertical g-forces. When
>> you're lying flat on your back wrt to the g-force, over 10g is survivable
>> even for several minutes, although uncomfortable.
>>
>>
>> On 14 May 2015 at 17:16, sraj sraj99@... [spacesettlers] <
>> spacesettlers@yahoogroups.com> wrote:
>>
>>>
>>>
>>> The *g* thresholds at which these effects occur depend on the training,
>>> age and fitness of the individual. An un-trained individual not used to the
>>> *g*-straining maneuver, can black out between 4 and 6 *g*, particularly
>>> if this is pulled suddenly. Roller coasters typically do not expose the
>>> occupants to much more than about 3 g. A hard slap on the face may impose
>>> hundreds of g-s locally but may not produce any obvious damage: a constant
>>> 15 g-s for a minute, however, may be deadly. A trained, fit individual
>>> wearing a *g* suit and practising the straining maneuver, can, with
>>> some difficulty, sustain up to 9*g* without loss of consciousness.
>>> http://en.wikipedia.org/wiki/High-G_training
>>>
>>> -------------
>>>
>>> We could get some idea of the problems, by mounting a small, hinged (to
>>> provide banking), residence on a centrifuge and testing on Earth.
>>>
>>> Regards,
>>> Selvaraj
>>>
>>> On 13 May 2015 at 22:33, Al Globus alglobus@... [spacesettlers] <
>>> spacesettlers@yahoogroups.com> 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.
>>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>> -Ian Woollard
>>
>>
>

For instance if you put 0.5 g on the centrifugue the module of the resulting vector will be sqrt(1g2+0.5g2)=1.12g
That's why this kind of experiment on partial gravity can *only* be done either in space or in the actual surface of a smaller planetary body.
On Fri, May 15, 2015 at 1:33 AM, sraj
sraj99@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

True. Yet by rotating the centrifuge in the 0 - 1g range (lateral component), we stand to get some idea of the problems if any we are going to face. If no one has any problem over say 10 days, we would have crossed a primary hurdle.
Regards,
Selvaraj
On 14 May 2015 at 22:39, Ian Woollard
ian.woollard@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

No, any problem is in the 0-1g range. You can't go below 1g on Earth.
Incidentally, those 4-6g ranges are mostly for vertical g-forces. When you're lying flat on your back wrt to the g-force, over 10g is survivable even for several minutes, although uncomfortable.
On 14 May 2015 at 17:16, sraj
sraj99@...m
[spacesettlers]
<
spacesettlers@yahoogroups.com
>
The
g
thresholds at which these effects occur depend on the training, age and fitness of the individual. An un-trained individual not used to the
g
-straining maneuver, can black out between 4 and 6
g
, particularly if this is pulled suddenly. Roller coasters typically do not expose the occupants to much more than about 3 g. A hard slap on the face may impose hundreds of g-s locally but may not produce any obvious damage: a constant 15 g-s for a minute, however, may be deadly. A trained, fit individual wearing a
g
suit and practising the straining maneuver, can, with some difficulty, sustain up to 9
g
without loss of consciousness.
http://en.wikipedia.org/wiki/High-G_training
We could get some idea of the problems, by mounting a small, hinged (to provide banking), residence on a centrifuge and testing on Earth.
Regards,
Selvaraj
On 13 May 2015 at 22:33, 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.
-Ian Woollard

There are two aspects to the problem of rotation:

1. The G levels experienced.
2. How the vestibular system reacts to rotation (the radius of rotation and
the angular velocity).

We could get some idea about (2) by using a centrifuge.

(Discovered Coelho's post when I was checking my sent mail.)

Regards,
Selvaraj

On 15 May 2015 at 22:54, Lucio de Souza Coelho lucioc@...
[spacesettlers] wrote:

>
> That would just add a lateral component to the 1g vector pointing down
> below, and in the end the resulting vector would be > 1g.
>
> For instance if you put 0.5 g on the centrifugue the module of the
> resulting vector will be sqrt(1g2+0.5g2)=1.12g
>
> That's why this kind of experiment on partial gravity can *only* be done
> either in space or in the actual surface of a smaller planetary body.
>
> On Fri, May 15, 2015 at 1:33 AM, sraj sraj99@... [spacesettlers] <
> spacesettlers@yahoogroups.com> wrote:
>
>>
>>
>> True. Yet by rotating the centrifuge in the 0 - 1g range (lateral
>> component), we stand to get some idea of the problems if any we are going
>> to face. If no one has any problem over say 10 days, we would have crossed
>> a primary hurdle.
>>
>> Regards,
>> Selvaraj
>>
>>
>> On 14 May 2015 at 22:39, Ian Woollard ian.woollard@...
>> [spacesettlers] wrote:
>>
>>>
>>>
>>> No, any problem is in the 0-1g range. You can't go below 1g on Earth.
>>>
>>> Incidentally, those 4-6g ranges are mostly for vertical g-forces. When
>>> you're lying flat on your back wrt to the g-force, over 10g is survivable
>>> even for several minutes, although uncomfortable.
>>>
>>>
>>> On 14 May 2015 at 17:16, sraj sraj99@... [spacesettlers] <
>>> spacesettlers@yahoogroups.com> wrote:
>>>
>>>>
>>>>
>>>> The *g* thresholds at which these effects occur depend on the
>>>> training, age and fitness of the individual. An un-trained individual not
>>>> used to the *g*-straining maneuver, can black out between 4 and 6 *g*,
>>>> particularly if this is pulled suddenly. Roller coasters typically do not
>>>> expose the occupants to much more than about 3 g. A hard slap on the face
>>>> may impose hundreds of g-s locally but may not produce any obvious damage:
>>>> a constant 15 g-s for a minute, however, may be deadly. A trained, fit
>>>> individual wearing a *g* suit and practising the straining maneuver,
>>>> can, with some difficulty, sustain up to 9*g* without loss of
>>>> consciousness.
>>>> http://en.wikipedia.org/wiki/High-G_training
>>>>
>>>> -------------
>>>>
>>>> We could get some idea of the problems, by mounting a small, hinged
>>>> (to provide banking), residence on a centrifuge and testing on Earth.
>>>>
>>>> Regards,
>>>> Selvaraj
>>>>
>>>> On 13 May 2015 at 22:33, Al Globus alglobus@... [spacesettlers] <
>>>> spacesettlers@yahoogroups.com> 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.
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> -Ian Woollard
>>>
>>>
>>
>

1. The G levels experienced.
2. How the vestibular system reacts to rotation (the radius of rotation and the angular velocity).
We could get some idea about (2) by using a centrifuge.
(Discovered Coelho's post when I was checking my sent mail.)
Regards,
Selvaraj
On 15 May 2015 at 22:54, Lucio de Souza Coelho
lucioc@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

That would just add a lateral component to the 1g vector pointing down below, and in the end the resulting vector would be 1g.
For instance if you put 0.5 g on the centrifugue the module of the resulting vector will be sqrt(1g2+0.5g2)=1.12g
That's why this kind of experiment on partial gravity can *only* be done either in space or in the actual surface of a smaller planetary body.
On Fri, May 15, 2015 at 1:33 AM, sraj
sraj99@...m
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

True. Yet by rotating the centrifuge in the 0 - 1g range (lateral component), we stand to get some idea of the problems if any we are going to face. If no one has any problem over say 10 days, we would have crossed a primary hurdle.
Regards,
Selvaraj
On 14 May 2015 at 22:39, Ian Woollard
ian.woollard@...
[spacesettlers]
<
spacesettlers@yahoogroups.com
>

No, any problem is in the 0-1g range. You can't go below 1g on Earth.
Incidentally, those 4-6g ranges are mostly for vertical g-forces. When you're lying flat on your back wrt to the g-force, over 10g is survivable even for several minutes, although uncomfortable.
On 14 May 2015 at 17:16, sraj
sraj99@...m
[spacesettlers]
<
spacesettlers@yahoogroups.com
>
The
g
thresholds at which these effects occur depend on the training, age and fitness of the individual. An un-trained individual not used to the
g
-straining maneuver, can black out between 4 and 6
g
, particularly if this is pulled suddenly. Roller coasters typically do not expose the occupants to much more than about 3 g. A hard slap on the face may impose hundreds of g-s locally but may not produce any obvious damage: a constant 15 g-s for a minute, however, may be deadly. A trained, fit individual wearing a
g
suit and practising the straining maneuver, can, with some difficulty, sustain up to 9
g
without loss of consciousness.
http://en.wikipedia.org/wiki/High-G_training
We could get some idea of the problems, by mounting a small, hinged (to provide banking), residence on a centrifuge and testing on Earth.
Regards,
Selvaraj
On 13 May 2015 at 22:33, 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.
-Ian Woollard