New paper suggests a much easier path to space settlement

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