OT Jeff Bezos: Forget Mars, humans will live in these free-floating space pod colonies

[a425couple]

from
https://www.cnbc.com/2019/03/08/jeff-bezos-mount-everest-is-a-garden-paradise-compared-to-mars.html

(interesting graphics at the citation)

Jeff Bezos: Forget Mars, humans will live in these free-floating space
pod colonies
Published Fri, Mar 8 2019 1:15 PM ESTUpdated Fri, Mar 8 2019 3:26 PM EST
Catherine Clifford
@CATCLIFFORD

Amazon CEO Jeff Bezos, founder of space venture Blue Origin and owner of
The Washington Post.Alex Wong | Getty Images News | Getty Images

Richest man alive Jeff Bezos says Mars is not a place humans would be
comfortable living.

“My friends who want to move to Mars? I say, ‘Do me a favor, go live on
the top of Mount Everest for a year first, and see if you like it —
because it’s a garden paradise compared to Mars,’” Bezos said at the
Yale Club in New York City in February, according to a Business Insider
transcript.

That is not to say that Bezos, who founded Amazon and aerospace company
Blue Origin, is not interested in sending regular people to space. Bezos
says moving to space will become necessary as the population is
expanding and Earth’s resources are finite. Eventually, an Earth-bound
population would face population control and energy rationing, Bezos said.

”...[T]hat to me seems like a pretty bleak world. We don’t have to have
that,” Bezos said.

There are currently over 7.6 billion people on earth, but if space
becomes a viable place for humans to live, the solar system has enough
resources to support 1 trillion humans, Bezos said. “Then we’d have
1,000 Mozarts and 1,000 Einsteins. Think how incredible and dynamic that
civilization will be.”

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@JeffBezos
The stunning Perito Moreno Glacier in Patagonia. We’ve sent robotic
probes to every planet in this solar system. Earth is BY FAR the best
one. We go to space to save the Earth. @BlueOrigin #NoPlanB
#GradatimFerociter

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However, said Bezos, “I don’t think we’ll live on planets.” Instead he
envisions humans living in self-sufficient space structures, like those
designed by Princeton physics professor Gerard O’Neil.

Below is an artist rendering of the exterior of what one of O’Neil’s
space settlements would look like.



Painting by Rick Guidice courtesy of NASA.

O’Neill’s space settlements include two cylinders, each 20 miles long
and 4 miles in diameter, according to the National Space Society. Below
is an artist rendering of the interior of one of the cylinders.



Painting by Rick Guidice courtesy of NASA.

“The space colonies we’ll build will have many advantages. The primary
one is that they’ll be close to Earth. The transit time and the amount
of energy required to move between planets is so high,” Bezos said.

“Ultimately what will happen, is this planet will be zoned residential
and light industry. We’ll have universities here and so on, but we won’t
do heavy industry here. Why would we? This is the gem of the solar
system. Why would we do heavy industry here? It’s nonsense.”

The artist rendering below is an artist rendering of inside of one of
O’Neill’s space settlement cylinders, according to the National Space
Society.



Painting by Don Davis courtesy of NASA.

Like Bezos, Tesla and SpaceX CEO Elon Musk believes humans will be a
multiplanetary species.

“I really believe in the future of space,” Musk said on Saturday at the
Kennedy Space Center in Florida after the launch of its unmanned rocket
ship Crew Dragon. “I think it is important that we become a space-faring
civilization and be out there among the stars ... We want the things
that are in science fiction novels and movies not be science fiction
forever. We want them to be real one day.”

However Musk envisions humans “terraforming” Mars, or making the surface
inhabitable, so people can live there. It will be extremely risky, says
Musk.

Embedded video

SpaceX
✔
@SpaceX
Supporting the creation of a permanent, self-sustaining human presence
on Mars. http://spacex.com/mars

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“It’s gonna be hard. There’s a good chance of death, going in a little
can through deep space. You might land successfully, [but] once you land
successfully, you’ll be working non-stop to build the base — so not much
time for leisure.

“And once you get there, even after all this, there’s a very harsh
environment, so there’s a good chance you’ll die there. We think you can
come back but we’re not sure,” Musk told Axios in November.

See also:

Elon Musk always thought SpaceX would ‘fail’ and he’d lose his PayPal
millions

Elon Musk defends plans to build a community on Mars after downbeat NASA
report

Elon Musk: Moving to Mars will cost less than $500,000, ‘maybe even
below $100,000’


1:26
Here’s what it will be like to travel to Mars in Elon Musk’s spaceship
Like this story? Subscribe to CNBC Make It on YouTube!

[Ted Nolan <tednolan>]

In article <qfe0f...@news2.newsguy.com>,

a425couple <a425c...@hotmail.com> wrote:
>from
>https://www.cnbc.com/2019/03/08/jeff-bezos-mount-everest-is-a-garden-paradise-compared-to-mars.html
>
>(interesting graphics at the citation)
>
>Jeff Bezos: Forget Mars, humans will live in these free-floating space
>pod colonies
>Published Fri, Mar 8 2019 1:15 PM ESTUpdated Fri, Mar 8 2019 3:26 PM EST
>Catherine Clifford
>@CATCLIFFORD
>
>Amazon CEO Jeff Bezos, founder of space venture Blue Origin and owner of
>The Washington Post.Alex Wong | Getty Images News | Getty Images
>
>Richest man alive Jeff Bezos says Mars is not a place humans would be
>comfortable living.

For a few more days :-(

>
>My friends who want to move to Mars? I say, Do me a favor, go live on
>the top of Mount Everest for a year first, and see if you like it
>because it's a garden paradise compared to Mars, Bezos said at the
>Yale Club in New York City in February, according to a Business Insider
>transcript.

Mars ain't the kind of place to raise your kids
In fact it's cold as hell
--
------
columbiaclosings.com
What's not in Columbia anymore..

[Lynn McGuire]

We need the gravity generator invented first before we start living in
space station. I wonder what the maintenance on a rotating space
station would look like ? Probably very intense due to the temperatures
of space and the stress of moving parts.

Lynn

[J. Clarke]

>> ?

>> ?

What moving parts?
>
>Lynn

[Lynn McGuire]

The rotating section proving something other than micro gravity in the
space station. A space station will need one until someone invents the
gravity generator.
https://www.youtube.com/watch?v=y-u2w17Vdrw

Lynn

[Sjouke Burry]

Just pile a few megatons of matter in orbit and you get the gravity for
free....
Added bonus: That shields you from harmful radiation.

[Lynn McGuire]

We're gonna need a way bigger spaceship lifter.

Lynn

[Alan Baker]

On 2019-07-01 4:01 p.m., Lynn McGuire wrote:
> We need the gravity generator invented first before we start living in
> space station.  I wonder what the maintenance on a rotating space
> station would look like ?  Probably very intense due to the temperatures
> of space and the stress of moving parts.

You are really and truly quite dim-witted, aren't you.

A rotating space station doesn't need to have any parts that move
relative to each other in order to rotate to create centripetal forces
to simulate gravity.

And the stresses are LESS on the structure in general because it is
highly doubtful you'd spin it fast enough to create 1g.

[J. Clarke]

On Mon, 1 Jul 2019 18:47:55 -0500, Lynn McGuire

Interesting that you show some impractical design from a me-too FX
extravaganza and not the classics.

<https://www.youtube.com/watch?v=0ZoSYsNADtY>
<https://www.youtube.com/watch?v=pWINrpzDQCY>
<https://www.youtube.com/watch?v=1ZImSTxbglI>

Note that the last has the whole concept explained by von Braun
personally.

I'm sorry, Lynn, but if you see moving parts as an issue you aren't
thinking.

[Lynn McGuire]

So you really think that a space ship is going to fly up to a space
station and rotate itself to match the space station rotation ? That
calls for a high level of precision that I do not see happening.

Lynn

[J. Clarke]

On Mon, 1 Jul 2019 19:59:15 -0500, Lynn McGuire

You've clearly never seen the Blue Angels, the Thunderbirds, or any
other group of fighter jocks showing off.

Further, a robot has landed on a rotating asteroid.

What leads you to believe that this is anything difficult? Line up on
the axis, center the target, rotate, approach.

[J. Clarke]

On Mon, 1 Jul 2019 19:59:15 -0500, Lynn McGuire

By the way, Von Braun thought it was viable. Considering that von
Braun pulled off several Moon landings and you can't even tell the
players, I'll take his judgment over yours thank you.

[David DeLaney]

On 2019-07-01, Lynn McGuire <lynnmc...@gmail.com> wrote:
> I wonder what the maintenance on a rotating space
> station would look like ? Probably very intense due to the temperatures
> of space and the stress of moving parts.

a), space has no temperature. Do you mean the problems of absorbed solar
radiation and radiation from the station into space?

b) Why would a rotating space station have moving parts? I mean relative to the
other parts of the space station, of course.

Dave, have you not been admonished by the City Fathers' designer recently?
--
\/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
my gatekeeper archives are no longer accessible :( / I WUV you in all CAPS! --K.

[Dimensional Traveler]

Without clicking on the YouTube link, why would it only be a _section_
of the station that rotates?


--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.

[Dimensional Traveler]

The Great Wall of China was built one brick and one shovelful of dirt at
a time.

[Alan Baker]

So matching rotation is somehow intrinsically more difficult than
matching translation?

[Alan Baker]

Because Lynn believes it would be hugely difficult to match rotation for
docking...

[Jaimie Vandenbergh]

On Mon, 1 Jul 2019 21:41:42 -0700, Dimensional Traveler
<dtr...@sonic.net> wrote:

>On 7/1/2019 4:47 PM, Lynn McGuire wrote:
>> On 7/1/2019 6:07 PM, J. Clarke wrote:
>>

>>> What moving parts?

>>
>> The rotating section proving something other than micro gravity in the
>> space station. A space station will need one until someone invents the
>> gravity generator.
>> https://www.youtube.com/watch?v=y-u2w17Vdrw
>>
>Without clicking on the YouTube link, why would it only be a _section_
>of the station that rotates?

There may be some interest in having the resupply dock rotate, to avoid
the Elite (space flight/trading sim computer game, current and 1980s)
problem of docking to a rotation frame of reference. But that is only to
compensate for fallible human brains which are notoriously poor at
dealing with the jump from cartesian to angular coordinates, automated
docking will have no need of it. Also it would have to play The Blue
Danube any time it was spinning.

A space station in rotation producing an approximation to gravity will
be far far easier to perform maintenance work on than it currently is in
microgravity. Go watch some of NASA's ISS or other in-space repair work.
Dealing with stuff that floats away, coping with needing to brace
everything all the time to stop your tool from rotating you instead of a
nut - anyone who's done spacewalks would be ecstatic at the chance to do
them in gravity instead of free floating. Even if they still had the
cumbersome suit on.

The negative issue is if something on the outside of the spinning
section needs work - then you're hanging "underneath" and working
upwards, which is a real pain.

Cheers - Jaimie
--
It's important to be comfortable in your own skin
because it's illegal to wear someone else's.

[Peter Trei]

A docking with rotating space station is also shown in 2001:

https://www.youtube.com/watch?v=q3oHmVhviO8

pt

[tonyn...@gmail.com]

And there's no one there to raise them if you did

[Lynn McGuire]

On 7/1/2019 8:48 PM, J. Clarke wrote:
...

>>>> The rotating section proving something other than micro gravity in the
>>>> space station. A space station will need one until someone invents the
>>>> gravity generator.
>>>> https://www.youtube.com/watch?v=y-u2w17Vdrw
>>>
>>> Interesting that you show some impractical design from a me-too FX
>>> extravaganza and not the classics.
>>>
>>> <https://www.youtube.com/watch?v=0ZoSYsNADtY>
>>> <https://www.youtube.com/watch?v=pWINrpzDQCY>
>>> <https://www.youtube.com/watch?v=1ZImSTxbglI>
>>>
>>> Note that the last has the whole concept explained by von Braun
>>> personally.
>>>
>>> I'm sorry, Lynn, but if you see moving parts as an issue you aren't
>>> thinking.
>>
>> So you really think that a space ship is going to fly up to a space
>> station and rotate itself to match the space station rotation ? That
>> calls for a high level of precision that I do not see happening.
>
> You've clearly never seen the Blue Angels, the Thunderbirds, or any
> other group of fighter jocks showing off.
>
> Further, a robot has landed on a rotating asteroid.
>
> What leads you to believe that this is anything difficult? Line up on
> the axis, center the target, rotate, approach.

Then why did NASA not design the ISS to be a rotating space station if
you say it is so easy to implement and maintain ?

Lynn

[Peter Trei]

Making a station rotate for gravity is an entirely different problem than
getting a spacecraft to match the rotation.

pt

[Scott Lurndal]

Perhaps because it was designed as a microgravity laboratory?

[Dimensional Traveler]

That's part of it. I suspect another part is budgetary. A space
station has to be LARGE for spinning it to be practical without serious
side effects. (Like "See? I sit here and pour and it ends up in the
glass of the guy two tables over!")

[Scott Lurndal]

But of what use would having gravity be in a microgravity laboratory?

It's an interesting point you bring up, however. How LARGE would
a rotating structure need to be to provide a reasonable simulation
of some fraction of one gravity without side effects such as you
mention?

[Alan Baker]

Because it adds other issues that make it unnecessary for that
particular station...

[Lynn McGuire]

On 7/1/2019 10:38 PM, David DeLaney wrote:
> On 2019-07-01, Lynn McGuire <lynnmc...@gmail.com> wrote:
>> I wonder what the maintenance on a rotating space
>> station would look like ? Probably very intense due to the temperatures
>> of space and the stress of moving parts.
>
> a), space has no temperature. Do you mean the problems of absorbed solar
> radiation and radiation from the station into space?
>
> b) Why would a rotating space station have moving parts? I mean relative to the
> other parts of the space station, of course.
>
> Dave, have you not been admonished by the City Fathers' designer recently?

The absence of temperature is called 0 K. However, space does have a
background temperature of around 2.7 K.
https://helios.gsfc.nasa.gov/qa_sp_ht.html

Heat transfer occurs from a high temperature to a low temperature.
There will always be heat transfer from a space station to space. And,
the outer skin and parts of the space station will be subjected to those
extreme temperatures which will cause deterioration over time. Seals,
welds, bolts, etc will be subjected to thermal stress as the space
station passes in and out of the sun's heating.

So, even if somebody was crazy enough to rotate a dock facility in the
middle of a space station, would there be no moving parts ? No, there
would be moving parts. At some point, you might want to close a door to
that docking facility so you can pressurize the bay and work on the
space ship outer skin in the relative comfort of air and just 0 F.

Lynn

[Alan Baker]

Let the furious backpedaling begin!

[Dimensional Traveler]

Off the top of my head I don't remember. I know many people have
calculated it. Some even put the math in their sci-fi stories! :)

[Peter Trei]

About 20m radius seems to be the consensus. I don't know how fast it would
spin, or what g it would produce.

THere's a NASA study, which was suggested as an ISS add-on sleeping quarters.
https://en.wikipedia.org/wiki/Nautilus-X
https://www.popsci.com/science/article/2011-02/new-nasa-reusable-spacecraft-concept-could-serve-multiple-missions-future/

OTOH, I also find claims that at >2 rpm, coriolis becomes noticable, though
people can get used to higher rates. At 2 rpm, you'd need a wheel 224m across
to get a full 1g.

Frankly, if most people can get used to living on a constantly rolling ship,
I expect we can handle some Coriolis.

pt

[Moriarty]

On Tuesday, July 2, 2019 at 6:50:49 PM UTC+10, Jaimie Vandenbergh wrote:
> On Mon, 1 Jul 2019 21:41:42 -0700, Dimensional Traveler
> <dtr...@sonic.net> wrote:
>
> >On 7/1/2019 4:47 PM, Lynn McGuire wrote:
> >> On 7/1/2019 6:07 PM, J. Clarke wrote:
> >>
> >>> What moving parts?
> >>
> >> The rotating section proving something other than micro gravity in the
> >> space station. A space station will need one until someone invents the
> >> gravity generator.
> >> https://www.youtube.com/watch?v=y-u2w17Vdrw
> >>
> >Without clicking on the YouTube link, why would it only be a _section_
> >of the station that rotates?
>
> There may be some interest in having the resupply dock rotate, to avoid
> the Elite (space flight/trading sim computer game, current and 1980s)
> problem of docking to a rotation frame of reference. But that is only to
> compensate for fallible human brains which are notoriously poor at
> dealing with the jump from cartesian to angular coordinates, automated
> docking will have no need of it. Also it would have to play The Blue
> Danube any time it was spinning.

That brought back some very pleasant memories. Right on, Commander!

-Moriarty

[Robert Carnegie]

Where did I read about a space station visitors' men's room
with an off-centre target mark on the urinal with the
words, "Aim here, dammit"?

I don't think it was _2001_!

[Jaimie Vandenbergh]

On Tue, 2 Jul 2019 15:20:38 -0700 (PDT), Moriarty <blu...@ivillage.com>
wrote:

Have you had a look at the modern instantiation, Elite: Dangerous? It's
a fabulous thing. https://youtu.be/weAoY7kw2NM?t=120

Cheers - Jaimie
--
"It's only work when somebody makes you do it." - Calvin

[Juho Julkunen]

In article <j1pnhelnbgvn4nsi1...@4ax.com>,
jai...@sometimes.sessile.org says...

The Stellar Forge is amazing, but does Braben have a brother to write a
musical for the game?

https://www.youtube.com/watch?v=rAkHGbRPNR4

--
Juho Julkunen

[Jaimie Vandenbergh]

On Wed, 3 Jul 2019 03:23:14 +0300, Juho Julkunen <giao...@hotmail.com>
wrote:

My word. I can't believe I was today years old when I first heard of
this. Thank you, I think.

Cheers - Jaimie
--
There's no place like 127.0.0.1

[Jack Bohn]

Scott Lurndal wrote:

> It's an interesting point you bring up, however. How LARGE would
> a rotating structure need to be to provide a reasonable simulation
> of some fraction of one gravity without side effects such as you
> mention?

Back in the 1970s, they thought maybe 3 rpm, which needs 100m to give 1g. That was the parameter of O'Neill's first cylinder. Further thought for the comfort of those traveling back and forth to the zero-g manufacturing facilities suggested limiting rotation to 1 rpm, needing around 900m for one g, which led to the Stanford Torus. (We still don't know what fraction between zero and 1 will halt the deleterious effects of freefall, or if it even will. Maybe we will just have a bit of gravity for the convenience of knowing things will stay where we put them, and which direction liquids will go.) The ISS is a bit longer than 100m, so put a big weight on one end, spinning it will look like the second-hand of a wall clock, going three times faster. With your feet at 100m from the center of rotation, the floor will be accelerating your mass inwards at 9.87 m/s/s; your inner ear, say 1.6m above the feet is accelerated at 9.69 m/s/s. I don't know if the inner ear is an accelerometer that way, whether the body crosschecks it against the sensation of weight from the other muscles, or if it would be bothered by the about 2% discrepancy. If I've calculated correctly, the ears are moving in a circle at 30.976 m/s, while the feet are moving in a (larger) circle at 31.416 m/s, or 0.44 m/s faster. If you drop something from that height, in the about 1/3 of a second while the floor is being accelerated towards it, it has moved 15 cm to one side. [That number, and what follows is almost certainly wrong, but I'll post it and try to wrap my head around the real situation.] To end the situation there does not give enough credit to Murphy. The momentum is probably not equalized between the floor and the falling object on contact; the object will probably bounce, and the floor skitter under it (at a speed in the range of 1 km/hr, nothing you couldn't chase down) until they have transferred the momentum, or until the object has gotten under a piece of furniture.

--
-Jack

[J. Clarke]

(a) it was designed by committee
(b) they had to launch it with the Space Shuttle instead of something
efficient
(c) it was the first real try at a multicomponent space station
(d) they had to do it on the same budget that wasy paying for (b)

[J. Clarke]

Except that you always have the option of stopping the rotation to do
the work, assuming that the thing has been designed to tolerate that
sort of thing (for example there's a cover for the swimming pool).

[J. Clarke]

On Tue, 2 Jul 2019 14:30:19 -0500, Lynn McGuire
<lynnmc...@gmail.com> wrote:

>On 7/1/2019 10:38 PM, David DeLaney wrote:
>> On 2019-07-01, Lynn McGuire <lynnmc...@gmail.com> wrote:
>>> I wonder what the maintenance on a rotating space
>>> station would look like ? Probably very intense due to the temperatures
>>> of space and the stress of moving parts.
>>
>> a), space has no temperature. Do you mean the problems of absorbed solar
>> radiation and radiation from the station into space?
>>
>> b) Why would a rotating space station have moving parts? I mean relative to the
>> other parts of the space station, of course.
>>
>> Dave, have you not been admonished by the City Fathers' designer recently?
>
>The absence of temperature is called 0 K. However, space does have a
>background temperature of around 2.7 K.
> https://helios.gsfc.nasa.gov/qa_sp_ht.html
>
>Heat transfer occurs from a high temperature to a low temperature.
>There will always be heat transfer from a space station to space. And,
>the outer skin and parts of the space station will be subjected to those
>extreme temperatures which will cause deterioration over time. Seals,
>welds, bolts, etc will be subjected to thermal stress as the space
>station passes in and out of the sun's heating.

The same issue with solar heating and cooling on a regular cycle
occurs on Earth you know. Engineering design doesn't have any trouble
coping with it. As for the background temperature, people who have
never taken a heat transfer course always act like this is some huge
deal. It's radiative transfer across an outstandingly good
vacuum--it's the same kind of issue as between the walls of a thermos
bottle, which are exceedingly efficient insulators despite having only
a very tiny span of much less good vacuum between them.

Solar heating is the same deal. You get pretty much the same amount
of solar heating in Earth orbit as you do at the Equator on the
Equinox. Yes, it can heat things up pretty well, but the Navy doesn't
seem to have any difficulty with things being exposed to sunlight then
dunked in water.

>So, even if somebody was crazy enough to rotate a dock facility in the
>middle of a space station, would there be no moving parts ? No, there
>would be moving parts. At some point, you might want to close a door to
>that docking facility so you can pressurize the bay and work on the
>space ship outer skin in the relative comfort of air and just 0 F.

Yes, there would be the same kind of moving parts that we have on
submarines and the like, only subject to a much more benign
environment (salt water doesn't like _anything_ while vacuum is
non-corrosive).

[Dimensional Traveler]

(e) multiple countries were each building modules for it

[Lynn McGuire]

Yes but one portion of the spin, the space station is radiating heat to
a black body at 3 K. And then in 20 ??? seconds, the space station is
absorbing solar radiation from the sun at 400 ??? 600 ??? K. That is a
fairly fast heating and cooling cycle.

We, the human race, have spent an enormous amount of time and and effort
developing materials that can live a long time between -40 F to 300 F.
Drop below -40 F and the material selection get very tricky. Drop below
-320 F (liquid nitrogen) and materials selection gets downright
difficult. We have the materials but they are in short supply and very
expensive. Just ask NASA and JPL. I don't even want to talk about
lubricants.

Lynn

[Peter Trei]

Many spacecraft already spin, to provide even heating and cooling over their
surface. The temperature cycling isn't nearly as big a problem as you seem to
think.

We even have dual-spin stabilized satellites, where most of the satellite
spins, but a platform holding antenna does not.

pt

[Juho Julkunen]

In article <ubunhelmhocu69hg4...@4ax.com>,
jai...@sometimes.sessile.org says...

I only learned of it a few days ago, so it was fresh on my mind. As you
might have noticed, the entire musical is on YouTube. I haven't
listened to it, but it makes me kinda happy to know it exists.

--
Juho Julkunen

[J. Clarke]

On Tue, 2 Jul 2019 23:34:24 -0500, Lynn McGuire

What part of "thermos bottle" are you having trouble with?

>We, the human race, have spent an enormous amount of time and and effort
>developing materials that can live a long time between -40 F to 300 F.
>Drop below -40 F and the material selection get very tricky. Drop below
>-320 F (liquid nitrogen) and materials selection gets downright
>difficult. We have the materials but they are in short supply and very
>expensive. Just ask NASA and JPL. I don't even want to talk about
>lubricants.

Why would the materials ever experience temperatures outside that
range?

[Thomas Koenig]

J Clarke <jclarke...@gmail.com> schrieb:

Granted the Space Shuttle was _far_ more epensive than originally
envisioned, but it got the job done.

Could we actually launch something the size and mass of the ISS
modules today? Hmm, it seems as if a Falcon Heavy should be able
to do it, at least looking at the specs on Wikipedia.

[Thomas Koenig]

Lynn McGuire <lynnmc...@gmail.com> schrieb:

> So, even if somebody was crazy enough to rotate a dock facility in the
> middle of a space station, would there be no moving parts ? No, there
> would be moving parts. At some point, you might want to close a door to
> that docking facility so you can pressurize the bay and work on the
> space ship outer skin in the relative comfort of air and just 0 F.

Well, you _could_ have no moving parts in an airlock, but it would
not be a very efficient, or very clean solution:

Use a multi-stage ferrofluid airlock.

[Thomas Koenig]

Lynn McGuire <lynnmc...@gmail.com> schrieb:

> Yes but one portion of the spin, the space station is radiating heat to
> a black body at 3 K. And then in 20 ??? seconds, the space station is
> absorbing solar radiation from the sun at 400 ??? 600 ??? K. That is a
> fairly fast heating and cooling cycle.

The faster it is, the less stressful it is for the material.

> We, the human race, have spent an enormous amount of time and and effort
> developing materials that can live a long time between -40 F to 300 F.
> Drop below -40 F and the material selection get very tricky. Drop below
> -320 F (liquid nitrogen) and materials selection gets downright
> difficult. We have the materials but they are in short supply and very
> expensive. Just ask NASA and JPL.

Stainless steel is actually fairly good (if heavy).

> I don't even want to talk about
> lubricants.

There is always Molybdenum Disulfide.

Elastomers can be more of a problem, at least if you go below the
glass temperatures of siloxanes.

[J. Clarke]

On Wed, 3 Jul 2019 21:17:10 -0000 (UTC), Thomas Koenig
<tko...@netcologne.de> wrote:

>J Clarke <jclarke...@gmail.com> schrieb:
>> On Tue, 2 Jul 2019 12:35:31 -0500, Lynn McGuire
>><lynnmc...@gmail.com> wrote:
>
>>>Then why did NASA not design the ISS to be a rotating space station if
>>>you say it is so easy to implement and maintain ?
>>
>> (a) it was designed by committee
>> (b) they had to launch it with the Space Shuttle instead of something
>> efficient
>
>Granted the Space Shuttle was _far_ more epensive than originally
>envisioned, but it got the job done.

No, it didn't. The _job_ was to bring launch costs down to a
reasonable level, and the Space Shuttle did not deliver.

>Could we actually launch something the size and mass of the ISS
>modules today?

Didn't need the Space Shuttle to do that. Saturn V was adequate to
the task.

>Hmm, it seems as if a Falcon Heavy should be able
>to do it, at least looking at the specs on Wikipedia.

Put it this way, Falcon Heavy can deliver more to effing _Mars_ than
the Space Shuttle could to the ISS.

[J. Clarke]

The concern, at least in real engineering, not Lynn-paranoid-fantasy
engineering, isn't moving parts per se but the continuous airtight
bearing that would have to be maintained for the kinds of things that
Hollywood special effects people like to depict, which are engineering
horrors for the most part.

[Alan Baker]

There's an interesting saga about the "big dumb booster" that NASA was
originally going to build as an stopgap solution for getting payloads
into orbit.

[John Halpenny]

Some of the modules were launched by the Shuttle, at about a billion dollars a flight. Many more modules of similar size and weight were launched on Proton rockets, at a bit over 50 million dollars a flight. This is why the Americans spent more than the Russians.

John

[Quadibloc]

On Monday, July 1, 2019 at 5:01:45 PM UTC-6, Lynn McGuire wrote:

> We need the gravity generator invented first before we start living in
> space station. I wonder what the maintenance on a rotating space

> station would look like ? Probably very intense due to the temperatures
> of space and the stress of moving parts.

At least a space station _can_ be made to rotate. We would need a gravity
generator even more badly for settlements on the Moon or Mars, where there is no
alternative way to get Earth-normal gravity.

The Earth rotates as a whole, so it doesn't have problems with moving parts. A
rotating space station probably would have non-rotating shielding, but that
would be basically just one or two points where bearings are required.

More to the point, there is at present no particular prospect known that we will
_ever_ invent a gravity generator, so if colonizing space is important enough
not to put off for a few million years, we had better plan to do without.

John Savard

[Quadibloc]

On Wednesday, July 3, 2019 at 3:17:12 PM UTC-6, Thomas Koenig wrote:

> Could we actually launch something the size and mass of the ISS
> modules today?

If not, Donald Trump had better say goodbye to the Lunar Gateway. So at the moment, NASA is definitely aiming at acquiring that capability in the near future.

John Savard

[Quadibloc]

On Monday, July 1, 2019 at 10:41:46 PM UTC-6, Dimensional Traveler wrote:

> Without clicking on the YouTube link, why would it only be a _section_
> of the station that rotates?

One reason not to have a whole station rotating is so that radiation shielding,
intended to shield even against secondary radiation from cosmic rays, won't have
to be supported by a structure able to contain its weight under Earth's gravity.

John Savard

[Quadibloc]

On Tuesday, July 2, 2019 at 2:50:49 AM UTC-6, Jaimie Vandenbergh wrote:
> Also it would have to play The Blue
> Danube any time it was spinning.

Actually, it would probably have to avoid doing that in order to avoid driving the
astronauts crazy.

John Savard

[Quadibloc]

On Tuesday, July 2, 2019 at 7:17:00 AM UTC-6, Peter Trei wrote:

> On Tuesday, July 2, 2019 at 4:50:49 AM UTC-4, Jaimie Vandenbergh wrote:

> > There may be some interest in having the resupply dock rotate, to avoid
> > the Elite (space flight/trading sim computer game, current and 1980s)
> > problem of docking to a rotation frame of reference.

> A docking with rotating space station is also shown in 2001:
>
> https://www.youtube.com/watch?v=q3oHmVhviO8

Which is no doubt why, when you buy the automatic docking computer in Elite, it
plays "The Blue Danube" when it is in operation.

John Savard

[Quadibloc]

This remains true, at least as an option, in the current version of the game:

https://www.youtube.com/watch?v=pxzHaFQn5Nk

John Savard

[Quadibloc]

On Tuesday, July 2, 2019 at 1:30:24 PM UTC-6, Lynn McGuire wrote:

> The absence of temperature is called 0 K. However, space does have a
> background temperature of around 2.7 K.
> https://helios.gsfc.nasa.gov/qa_sp_ht.html

It may not be strictly accurate to say that space has "no temperature". However,
while space is not a perfect vacuum, it closely approximates one.

Therefore, a vessel or station in space, if it is subject to thermal stresses,
will indeed experience them as a result of incident radiation, not contact with
the ambient medium, making David De Laney's point essentially correct.

John Savard

[Quadibloc]

On Monday, July 1, 2019 at 10:42:44 PM UTC-6, Dimensional Traveler wrote:
> On 7/1/2019 5:01 PM, Lynn McGuire wrote:
> > On 7/1/2019 6:54 PM, Sjouke Burry wrote:

> >> On 02.07.19 1:01, Lynn McGuire wrote:

> >>> We need the gravity generator invented first before we start living in
> >>> space station. I wonder what the maintenance on a rotating space
> >>> station would look like ? Probably very intense due to the temperatures
> >>> of space and the stress of moving parts.

> >> Just pile a few megatons of matter in orbit and you get the gravity
> >> for free....
> >> Added bonus: That shields you from harmful radiation.

> > We're gonna need a way bigger spaceship lifter.

> The Great Wall of China was built one brick and one shovelful of dirt at
> a time.

This is true, but building a planet seems an awfully expensive way to build a
space station.

John Savard

[Quadibloc]

On Tuesday, July 2, 2019 at 1:30:51 AM UTC-6, Alan Baker wrote:

> Because Lynn believes it would be hugely difficult to match rotation for
> docking...

Since 2001: A Space Odyssey was just a movie, and Elite was just a computer
game, it's not immediately obvious that he couldn't be right.

I think having a non-rotating space station portion is needed so that several
metres of rock could be used as shielding - small amounts of radiation only make
things worse, because cosmic rays induce secondary radiation.

However, having a one-piece rotating space station inside a one-piece non-
rotating radiation shielding enclosure does not involve a large number of moving
parts.

John Savard

[Alan Baker]

It's hardly an insurmountable engineering challenge to simply rotate the
shielding as well...

[J. Clarke]

On Wed, 3 Jul 2019 22:45:02 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
wrote:

It's aiming at distributing more pork in the near future.

[J. Clarke]

On Wed, 3 Jul 2019 23:11:15 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
wrote:

>On Tuesday, July 2, 2019 at 1:30:51 AM UTC-6, Alan Baker wrote:
>
>> Because Lynn believes it would be hugely difficult to match rotation for
>> docking...
>
>Since 2001: A Space Odyssey was just a movie, and Elite was just a computer
>game, it's not immediately obvious that he couldn't be right.

You dismiss von Braun completely.

>I think having a non-rotating space station portion is needed so that several
>metres of rock could be used as shielding - small amounts of radiation only make
>things worse, because cosmic rays induce secondary radiation.

Has the lack of several meters of rock been an issue for the ISS?

>However, having a one-piece rotating space station inside a one-piece non-
>rotating radiation shielding enclosure does not involve a large number of moving
>parts.

Except that now you have the problem of preventing the rotating part
from colliding with the nonrotating part, unless you put some hardware
in place to keep them separated, and, voila, moving parts.

[J. Clarke]

On Wed, 3 Jul 2019 22:47:07 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
wrote:

Except that that is not the design shown in the link that you did not
click or in any other design that I have seen depicted anywhere that
involved rotating and non-rotating portions of the same vehicle.

[Quadibloc]

On Thursday, July 4, 2019 at 6:38:19 AM UTC-6, J. Clarke wrote:

> Except that now you have the problem of preventing the rotating part
> from colliding with the nonrotating part, unless you put some hardware
> in place to keep them separated, and, voila, moving parts.

Yes, some moving parts, but only a minimal number.

As the shielding needs to be very thick and heavy, making it rotate for 1g or even
more, as it surrounds the habitat, would be quite unreasonable.

John Savard

[J. Clarke]

On Thu, 4 Jul 2019 07:13:57 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
wrote:

>On Thursday, July 4, 2019 at 6:38:19 AM UTC-6, J. Clarke wrote:
>
>> Except that now you have the problem of preventing the rotating part
>> from colliding with the nonrotating part, unless you put some hardware
>> in place to keep them separated, and, voila, moving parts.
>
>Yes, some moving parts, but only a minimal number.

That have to work constantly, forever. That's the problem.

>As the shielding needs to be very thick and heavy, making it rotate for 1g or even
>more, as it surrounds the habitat, would be quite unreasonable.

Nahh, just means more structure, that adds to the shielding.

[Quadibloc]

On Thursday, July 4, 2019 at 6:40:15 AM UTC-6, J. Clarke wrote:

> Except that that is not the design shown in the link that you did not
> click or in any other design that I have seen depicted anywhere that
> involved rotating and non-rotating portions of the same vehicle.

For long-term habitation, radiation needs to be taken care of as well as the Earth
takes care of it.

Here is how I would address the issue:

http://www.quadibloc.com/science/spaint.htm

However, except for one minor detail, the design is not really original with me.
The basic principle is already present in a design from MIT - that design was
based on the Stanford Torus, but surrounded the torus with non-rotating
shielding.

John Savard

[Quadibloc]

But structure that has to have *tensile strength*, so making it is much harder
than just hauling up waste rock and just putting in enough structure to barely
hold it in position.

John Savard

[Quadibloc]

On Thursday, July 4, 2019 at 6:38:19 AM UTC-6, J. Clarke wrote:
> On Wed, 3 Jul 2019 23:11:15 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
> wrote:

> >I think having a non-rotating space station portion is needed so that several
> >metres of rock could be used as shielding - small amounts of radiation only make
> >things worse, because cosmic rays induce secondary radiation.

> Has the lack of several meters of rock been an issue for the ISS?

The ISS tests whether or not humans can survive the extreme conditions of a
journey to Mars on a lightweight spaceship made with current technology.

In space, people are exposed to more radiation dosage than they naturally
receive on Earth.

I propose a space habitat that eliminates these issues. Have enough shielding to
duplicate the performance of the Earth's atmosphere, and have Earth-normal
gravity. That way, the ability of humans to survive is proven by experience on
Earth.

John Savard

[J. Clarke]

On Thu, 4 Jul 2019 07:23:59 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>

wrote:

>On Thursday, July 4, 2019 at 8:16:06 AM UTC-6, J. Clarke wrote:
>> On Thu, 4 Jul 2019 07:13:57 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
>> wrote:
>
>> >As the shielding needs to be very thick and heavy, making it rotate for 1g or even
>> >more, as it surrounds the habitat, would be quite unreasonable.
>
>> Nahh, just means more structure, that adds to the shielding.
>
>But structure that has to have *tensile strength*, so making it is much harder
>than just hauling up waste rock and just putting in enough structure to barely
>hold it in position.

The cost of hauling is greater than the cost of the material so there
is little economic benefit to hauling "waste rock".

[J. Clarke]

On Thu, 4 Jul 2019 07:26:24 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>

wrote:

>On Thursday, July 4, 2019 at 6:38:19 AM UTC-6, J. Clarke wrote:
>> On Wed, 3 Jul 2019 23:11:15 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
>> wrote:
>
>> >I think having a non-rotating space station portion is needed so that several
>> >metres of rock could be used as shielding - small amounts of radiation only make
>> >things worse, because cosmic rays induce secondary radiation.
>
>> Has the lack of several meters of rock been an issue for the ISS?
>
>The ISS tests whether or not humans can survive the extreme conditions of a
>journey to Mars on a lightweight spaceship made with current technology.

That is not the purpose for which it was constructed.

>In space, people are exposed to more radiation dosage than they naturally
>receive on Earth.

In low earth orbit would you care to quantify how much more?
Hint--google "van Allen belts" and then after you finish panicking
look at their altitudes vs the altitude of the space station.

>I propose a space habitat that eliminates these issues.

Propose away.

>Have enough shielding to
>duplicate the performance of the Earth's atmosphere, and have Earth-normal
>gravity. That way, the ability of humans to survive is proven by experience on
>Earth.

Until the bearings fail and the thing tears itself apart. You and
Lynn both seem to be deliberately trying to force incompetent
engineering on us.

[J. Clarke]

On Thu, 4 Jul 2019 07:20:29 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
wrote:

>On Thursday, July 4, 2019 at 6:40:15 AM UTC-6, J. Clarke wrote:
>
>> Except that that is not the design shown in the link that you did not
>> click or in any other design that I have seen depicted anywhere that
>> involved rotating and non-rotating portions of the same vehicle.
>
>For long-term habitation, radiation needs to be taken care of as well as the Earth
>takes care of it.

Why? Show us numbers based on ambient radiation levels for lifetime
exposure.

>Here is how I would address the issue:
>
>http://www.quadibloc.com/science/spaint.htm
>
>However, except for one minor detail, the design is not really original with me.
>The basic principle is already present in a design from MIT - that design was
>based on the Stanford Torus, but surrounded the torus with non-rotating
>shielding.

Why not make all that shielding part of the structure and make it less
likely that there will be a structural failure in the rotating
assembly? Instead of the 1.5:1 margins typical in flight structures,
with all that mass why not make it 150:10 or 1500:1?

[Peter Trei]

On Thursday, July 4, 2019 at 10:37:57 AM UTC-4, J. Clarke wrote:
> On Thu, 4 Jul 2019 07:26:24 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
> wrote:
>
> >On Thursday, July 4, 2019 at 6:38:19 AM UTC-6, J. Clarke wrote:
> >> On Wed, 3 Jul 2019 23:11:15 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
> >> wrote:
> >
> >> >I think having a non-rotating space station portion is needed so that several
> >> >metres of rock could be used as shielding - small amounts of radiation only make
> >> >things worse, because cosmic rays induce secondary radiation.
> >
> >> Has the lack of several meters of rock been an issue for the ISS?
> >
> >The ISS tests whether or not humans can survive the extreme conditions of a
> >journey to Mars on a lightweight spaceship made with current technology.
>
> That is not the purpose for which it was constructed.
>
> >In space, people are exposed to more radiation dosage than they naturally
> >receive on Earth.
>
> In low earth orbit would you care to quantify how much more?
> Hint--google "van Allen belts" and then after you finish panicking
> look at their altitudes vs the altitude of the space station.

Correct - the ISS is sheilded primarily by the Earth's magnetic field.
Radiation is more of a concern further out, for interplanetary travel.
If we'd had a bad solar flare during Apollo, we'd have lost a mission.

> >I propose a space habitat that eliminates these issues.
>
> Propose away.
>
> >Have enough shielding to
> >duplicate the performance of the Earth's atmosphere, and have Earth-normal
> >gravity. That way, the ability of humans to survive is proven by experience on
> >Earth.

As with his political 'solutions' Quaddie totally ignores the cost of
providing his solution.

> Until the bearings fail and the thing tears itself apart. You and
> Lynn both seem to be deliberately trying to force incompetent
> engineering on us.

We *already* do this - there are satellites which have a rotating body, and
a stationary antenna array. Its a mature technology, and they operate for
many years reliably, with zero inspections and maintenance.

Making one that can maintain a continuous livable atmosphere through the
bearing is a much harder problem.

pt

[Quadibloc]

Depends where you're hauling it from. Lunar material.

[J. Clarke]

On Thu, 4 Jul 2019 11:02:41 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
wrote:

>Depends where you're hauling it from. Lunar material.

While that's true to some extent, it's still wasting mass to just use
it for one thing. Further, if you're building from lunar material
you're already set up to turn it into structural material so why start
a new line to load and ship tailings?

[Quadibloc]

Aluminum and Titanium are easy enough to find on the Moon. I'm not sure they
make great radiation shielding - plain rock is likely to be better.

For the huge amounts of shielding that cosmic rays make necessary, sending up
unprocessed rock from the Moon, and not planning to use terrestrial material, is
reasonable. This, though, presumes enough iron can be mined on the Moon to make
a mass driver possible.

John Savard

[David Johnston]

> On Monday, July 1, 2019 at 10:41:46 PM UTC-6, Dimensional Traveler wrote:
>
>> Without clicking on the YouTube link, why would it only be a _section_
>> of the station that rotates?
>

Does anything want to dock with it ever?

[J. Clarke]

On Thu, 4 Jul 2019 16:56:25 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>

wrote:

>On Thursday, July 4, 2019 at 1:08:09 PM UTC-6, J. Clarke wrote:
>> On Thu, 4 Jul 2019 11:02:41 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
>> wrote:
>
>> >Depends where you're hauling it from. Lunar material.
>
>> While that's true to some extent, it's still wasting mass to just use
>> it for one thing. Further, if you're building from lunar material
>> you're already set up to turn it into structural material so why start
>> a new line to load and ship tailings?
>
>Aluminum and Titanium are easy enough to find on the Moon. I'm not sure they
>make great radiation shielding - plain rock is likely to be better.
>
>For the huge amounts of shielding that cosmic rays make necessary, sending up
>unprocessed rock from the Moon, and not planning to use terrestrial material, is
>reasonable. This, though, presumes enough iron can be mined on the Moon to make
>a mass driver possible.

First you have to make a compelling argument that cosmic rays are a
problem. For a station in Earth Orbit that's a pretty hard sell--at
most the ISS gets 30x what someone on the ground gets. Since death
from radiation effects is not a common cause of death it's difficult
to argue convincingly that that's enough to justify radical measures.

If you're not talking about something in Earth orbit then you have a
different problem--cosmic rays are the least of your worries, and you
should be worrying about the things that actually compose most of the
hazard.

As for your rock vs metal, you blather about titanium and wonder about
iron--the most abundant elements on the lunar surface are in order
oxygen, silicon, iron, calcium, aluminum, and magnesium. Everything
else is less than 5%.

Now, your "plain old rock" is going to be mostly composed of those
substances. So why is "plain old rock" that is mostly oxygen better
than a denser material?

When you're talking about production of materials on the Moon though,
you've already got the long-term space station in Earth orbit in
place--you need that as a relay point for your lunar construction,
that can't use lunar materials until you've shipped enough
infrastructure to start extracting them.

[David Johnston]

On 2019-07-04 6:38 a.m., J. Clarke wrote:
> On Wed, 3 Jul 2019 23:11:15 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
> wrote:
>
>> On Tuesday, July 2, 2019 at 1:30:51 AM UTC-6, Alan Baker wrote:
>>
>>> Because Lynn believes it would be hugely difficult to match rotation for
>>> docking...
>>
>> Since 2001: A Space Odyssey was just a movie, and Elite was just a computer
>> game, it's not immediately obvious that he couldn't be right.
>
> You dismiss von Braun completely.
>
>> I think having a non-rotating space station portion is needed so that several
>> metres of rock could be used as shielding - small amounts of radiation only make
>> things worse, because cosmic rays induce secondary radiation.
>
> Has the lack of several meters of rock been an issue for the ISS?

Fortunately people don't actually live there for years.

[Alan Baker]

What makes you think you can't dock with a docking station that's rotating?

[Gene Wirchenko]

On Tue, 2 Jul 2019 12:00:11 -0700, Dimensional Traveler
<dtr...@sonic.net> wrote:

[snip]

>That's part of it. I suspect another part is budgetary. A space
>station has to be LARGE for spinning it to be practical without serious
>side effects. (Like "See? I sit here and pour and it ends up in the
>glass of the guy two tables over!")

"Excuse me, miss. The gentleman two tables over would like to
pour you a drink."

Sincerely,

Gene Wirchenko

[Peter Trei]

As we so often do this group, we're all speculating far ahead of the available
data.

I expect there's a big difference between 'Coriolis Force can't be detected
without instruments', and 'Coriolis Force can be lived with for long periods'.
After all, human have lived on rolling ships at sea for months at a time. The
human inner ear can deal with quite a lot.

The other problems, such as pouring a drink, are just a matter of training
and practice.

pt

[Peter Trei]

On Tuesday, July 2, 2019 at 3:00:13 PM UTC-4, Dimensional Traveler wrote:
> On 7/2/2019 11:48 AM, Scott Lurndal wrote:
> > Lynn McGuire <lynnmc...@gmail.com> writes:
> >> On 7/1/2019 8:48 PM, J. Clarke wrote:
> >> ...
> >>>>>> The rotating section proving something other than micro gravity in the
> >>>>>> space station. A space station will need one until someone invents the
> >>>>>> gravity generator.
> >>>>>> https://www.youtube.com/watch?v=y-u2w17Vdrw
> >>>>>
> >>>>> Interesting that you show some impractical design from a me-too FX
> >>>>> extravaganza and not the classics.
> >>>>>
> >>>>> <https://www.youtube.com/watch?v=0ZoSYsNADtY>
> >>>>> <https://www.youtube.com/watch?v=pWINrpzDQCY>
> >>>>> <https://www.youtube.com/watch?v=1ZImSTxbglI>
> >>>>>
> >>>>> Note that the last has the whole concept explained by von Braun
> >>>>> personally.
> >>>>>
> >>>>> I'm sorry, Lynn, but if you see moving parts as an issue you aren't
> >>>>> thinking.
> >>>>
> >>>> So you really think that a space ship is going to fly up to a space
> >>>> station and rotate itself to match the space station rotation ? That
> >>>> calls for a high level of precision that I do not see happening.
> >>>
> >>> You've clearly never seen the Blue Angels, the Thunderbirds, or any
> >>> other group of fighter jocks showing off.
> >>>
> >>> Further, a robot has landed on a rotating asteroid.
> >>>
> >>> What leads you to believe that this is anything difficult? Line up on
> >>> the axis, center the target, rotate, approach.
> >>
> >> Then why did NASA not design the ISS to be a rotating space station if
> >> you say it is so easy to implement and maintain ?
> >>
> >
> > Perhaps because it was designed as a microgravity laboratory?

> >
> That's part of it. I suspect another part is budgetary. A space
> station has to be LARGE for spinning it to be practical without serious
> side effects. (Like "See? I sit here and pour and it ends up in the
> glass of the guy two tables over!")

That's not a 'serious effect'. That's an effect which is completely predictable,
and easily compensated for if you know its coming.

The level we need to worry about is that which makes it difficult for humans
to function, even after acclimation.

As anyone who's spent time on a ship at sea knows, it takes a while to acquire
'sea legs'.

pt

[Alan Baker]

Indeed. There are people who suffer from vertigo who learn to basically
"ignore" the inner ear's signals

[Lynn McGuire]

You know, you throw around the word incompetent fairly casually. That
word is grounds for slander in Texas, especially for a registered
Professional Engineer such as myself. Do you drive a nice vehicle ? I
am driving an old Ford Expedition with 209K miles on it, I sure could
use a new one.

Lynn

[Lynn McGuire]

Just resupply the space station with more consumables daily through the
space elevator.

Lynn

[Lynn McGuire]

On 7/4/2019 1:06 AM, Quadibloc wrote:
> On Tuesday, July 2, 2019 at 1:30:24 PM UTC-6, Lynn McGuire wrote:
>
>> The absence of temperature is called 0 K. However, space does have a
>> background temperature of around 2.7 K.
>> https://helios.gsfc.nasa.gov/qa_sp_ht.html
>
> It may not be strictly accurate to say that space has "no temperature". However,
> while space is not a perfect vacuum, it closely approximates one.
>
> Therefore, a vessel or station in space, if it is subject to thermal stresses,
> will indeed experience them as a result of incident radiation, not contact with
> the ambient medium, making David De Laney's point essentially correct.
>
> John Savard

I think that I will let you lick the uninsulated outer wall of the space
station first.

Lynn

[Lynn McGuire]

On 7/4/2019 12:42 AM, Quadibloc wrote:
> On Monday, July 1, 2019 at 5:01:45 PM UTC-6, Lynn McGuire wrote:
>
>> We need the gravity generator invented first before we start living in
>> space station. I wonder what the maintenance on a rotating space
>> station would look like ? Probably very intense due to the temperatures
>> of space and the stress of moving parts.
>
> At least a space station _can_ be made to rotate. We would need a gravity
> generator even more badly for settlements on the Moon or Mars, where there is no
> alternative way to get Earth-normal gravity.
>
> The Earth rotates as a whole, so it doesn't have problems with moving parts. A
> rotating space station probably would have non-rotating shielding, but that
> would be basically just one or two points where bearings are required.
>
> More to the point, there is at present no particular prospect known that we will
> _ever_ invent a gravity generator, so if colonizing space is important enough
> not to put off for a few million years, we had better plan to do without.
>
> John Savard

Most SF writers regard the lower gravity of the Moon and Mars as a
feature rather than a problem. Retire to the Moon and live in a easy
place to walk !

Of course the space born kids might have brittle bones but, that is
another problem.

Lynn

[Alan Baker]

You know, the context in which he used the word makes that complete
nonsense, don't you?

I guess for a professional engineer, you're incompetent... ...as a lawyer.

:-)

[Dimensional Traveler]

I resent that! I am not speculating. I was being a smartass! :)


--
Inquiring minds want to know while minds with a self-preservation
instinct are running screaming.

[J. Clarke]

Your graceless concession of the point is accepted.

[J. Clarke]

You're again presupposing technology for the construction of which a
space station is required.

[Lynn McGuire]

We had a sailboat (41 ft sloop) when I was growing up that we shared
with three other families (it was our dad's pride and joy). I never had
seasickness problems in it, even with 10+ ft seas.

I was on 100+ ft Gulf of Mexico fishing boat a couple of years ago. He
had side thrusters on it and spun the boat twice around to track the
redfish school that we were trying to catch. I hurled. Then I caught a
20 inch redfish. My fellow fisherpeople were not pleased.

Lynn

[J. Clarke]

There seems to be a propensity but also a training factor and an age
effect. I hurled repeatedly my first couple of days at sea but then
didn't have another problem--at one point I stood a double watch
because the weather was kicking up and the Chief couldn't find anybody
else who was functional enough to stand it. At one point I remember
standing on the bridge wing having the time of my life while the
Captain and the XO hung over the rail hurling their guts out behind
me.
>
>Lynn

[Peter Trei]

IANAL, but I expect that you (Lynn) would have to demonstrate that you've
suffered financial loss due to that Usenet post.

Good luck.

Every single person here is ignorant and incompetent in most fields of human
endeavor. Many of us are hypercompetent - that is, experts - in one or two
areas. I would not dare to contradict you on issue of fossil fuel extraction,
handling, and use.

OTOH, you were recently surprised to learn that stopping the rotation of the
Earth would leave its gravitational field intact. That's middle school physics,
and you got it wrong. I infer that I can't consider you an expert on orbital
mechanics, and related engineering.

Being able to recognize where one's opinion is actually well-qualified and
expert, and where one is an ignorant layman, is a useful skill.

pt

[Dimensional Traveler]

It never occurred to them to chum for redfish?

[Quadibloc]

On Thursday, July 4, 2019 at 8:37:57 AM UTC-6, J. Clarke wrote:
> On Thu, 4 Jul 2019 07:26:24 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
> wrote:

> >Have enough shielding to
> >duplicate the performance of the Earth's atmosphere, and have Earth-normal
> >gravity. That way, the ability of humans to survive is proven by experience on
> >Earth.

> Until the bearings fail and the thing tears itself apart. You and
> Lynn both seem to be deliberately trying to force incompetent
> engineering on us.

I make no claims to being an engineer, but certainly I would not try, say for
pork-barrel purposes, to have the bearings supplied by an unqualified
contractor. Of course, high-quality bearings may not be the solution - an overall design that avoids a single point of failure, and which leads to failures being graceful, is more appropriate.

John Savard

[Quadibloc]

On Thursday, July 4, 2019 at 9:02:53 AM UTC-6, Peter Trei wrote:

> We *already* do this - there are satellites which have a rotating body, and
> a stationary antenna array. Its a mature technology, and they operate for
> many years reliably, with zero inspections and maintenance.

Yes, but in my case, the masses involved are much greater.

> Making one that can maintain a continuous livable atmosphere through the
> bearing is a much harder problem.

That is not a problem in the sort of design I am discussing:

http://www.quadibloc.com/science/spaint.htm

the portion of the space habitat which contains atmosphere rotates as a unit,
and the bearing assembly would be entirely in the portion that is in vacuum. I was leaving the nature of the bearings as a problem for competent engineers; a low-tech pivot in a cone at one end, and something with magnetic repulsion at the other might be one possibility.

A layer of PTFE hollow cylinders between the cylindrical habitat and the shell
of shielding to provide more distributed bracing might have more friction but
better safety characteristics.

John Savard

[Quadibloc]

On Thursday, July 4, 2019 at 9:02:53 AM UTC-6, Peter Trei wrote:

> As with his political 'solutions' Quaddie totally ignores the cost of
> providing his solution.

I originated it as an existence proof, in a reply to a claim I heard that cosmic
rays meant that O'Neill colonies were an impossible pipe dream, so that criticism
is valid.

John Savard

[J. Clarke]

On Sat, 6 Jul 2019 01:00:10 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>

wrote:

>On Thursday, July 4, 2019 at 8:37:57 AM UTC-6, J. Clarke wrote:
>> On Thu, 4 Jul 2019 07:26:24 -0700 (PDT), Quadibloc <jsa...@ecn.ab.ca>
>> wrote:
>
>> >Have enough shielding to
>> >duplicate the performance of the Earth's atmosphere, and have Earth-normal
>> >gravity. That way, the ability of humans to survive is proven by experience on
>> >Earth.
>
>> Until the bearings fail and the thing tears itself apart. You and
>> Lynn both seem to be deliberately trying to force incompetent
>> engineering on us.
>
>I make no claims to being an engineer, but certainly I would not try, say for
>pork-barrel purposes, to have the bearings supplied by an unqualified
>contractor. Of course, high-quality bearings may not be the solution - an overall design that avoids a single point of failure, and which leads to failures being graceful, is more appropriate.

I am pretty sure that the bearings on Kepler were made by "qualified
suppliers".

It doesn't matter who made them, bearings have a finite service life
and sometimes fail prematurely. One of the failure modes is seizure,
which when there are large amounts of energy involved, generally
results in something breaking.