Author Topic: Which is easier, building industry on planets, or in space?  (Read 25944 times)

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
I think the advantages of O'Neil type colonies vs building civilization and industry on planetary surfaces are often not recognized.

In space you can have whatever strength of gravity that suits the process you're performing, you can have 24/7 sunlight - at 1 AU from the sun that's over a kW of free energy for each m^2of collection surface, you can have temperatures of thousands of degrees using mirrors, and still have near absolute zero temperatures in the shade only inches away.

You don't have to contend with a pesky atmosphere, and you don't have to battle that gravity every time you bring something in or take something out.

Even the raw materials are available in the form of NEO's, a meteoroid just 50 meters in diameter masses over a 150,000 tonnes (at 2.5g/cc).

I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Solman

  • Full Member
  • ****
  • Posts: 675
  • Liked: 9
  • Likes Given: 9
 If you locate the initial effort in GEO you can have teleoperation at low latency, dead sats for initial raw material, and then asteroid regolith harvested by vehicles largely made of dead sats. All with nearly constant sunlight.

Sol

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline DarkenedOne

  • Full Member
  • ****
  • Posts: 953
  • Liked: 56
  • Likes Given: 8
I think the advantages of O'Neil type colonies vs building civilization and industry on planetary surfaces are often not recognized.

In space you can have whatever strength of gravity that suits the process you're performing, you can have 24/7 sunlight - at 1 AU from the sun that's over a kW of free energy for each m^2of collection surface, you can have temperatures of thousands of degrees using mirrors, and still have near absolute zero temperatures in the shade only inches away.

You don't have to contend with a pesky atmosphere, and you don't have to battle that gravity every time you bring something in or take something out.

Even the raw materials are available in the form of NEO's, a meteoroid just 50 meters in diameter masses over a 150,000 tonnes (at 2.5g/cc).

It all matters on the industry.  All things have to be taken into consideration including energy, local resources, available technology, and etc. 

Surely some industries will prefer space whereas others will prefer the surface.

Offline DarkenedOne

  • Full Member
  • ****
  • Posts: 953
  • Liked: 56
  • Likes Given: 8
None of you have mentioned one of the most important factors, gravity and the human body.

Artificial gravity on space stations is quite doable by rotation.  The gravity on a planet like Mars cannot be altered.  Since 1g gravity is required to long term habitation, the only acceptable location for permanent human presence in space is on space stations.     

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 219
  • Likes Given: 12
Since 1g gravity is required to long term habitation, the only acceptable location for permanent human presence in space is on space stations.     

Prove it.

Offline DarkenedOne

  • Full Member
  • ****
  • Posts: 953
  • Liked: 56
  • Likes Given: 8
Since 1g gravity is required to long term habitation, the only acceptable location for permanent human presence in space is on space stations.     

Prove it.

What is there to prove?  Unless a way to eliminate the negative effects of low or zero gravity on humans, then permanent human settlement on low gravity objects can be ruled out.

The only way we know to counter eliminate these effects is by centrifugal force.

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
A lot of things in even fractional gee are far improved over zero gravity.

There's no compelling proof I've seen that Mars gravity will be insufficient for long-term habitation.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Eric Hedman

  • Full Member
  • ****
  • Posts: 850
  • Liked: 247
  • Likes Given: 225
A lot of things in even fractional gee are far improved over zero gravity.

There's no compelling proof I've seen that Mars gravity will be insufficient for long-term habitation.
Wasn't the canceled centrifuge for the ISS supposed to settle this?

Offline strangequark

  • Full Member
  • ****
  • Posts: 1074
  • Co-Founder, Tesseract Space
  • San Francisco, CA
  • Liked: 219
  • Likes Given: 12
What is there to prove?  Unless a way to eliminate the negative effects of low or zero gravity on humans, then permanent human settlement on low gravity objects can be ruled out.

The only way we know to counter eliminate these effects is by centrifugal force.

My point is that we have very little data. We don't know if the negative effects are linear, or if there's a knee in the curve that you can stay above and keep the bulk of those problems at bay. There is some minimum acceptable limit of gravity for long term human habitation. The only places on the curve that we have long term data are 1g and 0g.

Mars gravity could very well be sufficient. Lunar gravity might be. Heck, even Ceres gravity might be. So, I strongly object to your contention that 1g is required for long term human habitation.

Offline Jorge

  • Senior Member
  • *****
  • Posts: 6180
  • Liked: 32
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #10 on: 08/19/2011 08:07 PM »
A lot of things in even fractional gee are far improved over zero gravity.

There's no compelling proof I've seen that Mars gravity will be insufficient for long-term habitation.
Wasn't the canceled centrifuge for the ISS supposed to settle this?

No, not for humans. Would have provided some analog data for small mammals.
JRF

Offline MickQ

  • Full Member
  • ****
  • Posts: 503
  • Australia.
  • Liked: 52
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #11 on: 08/19/2011 11:44 PM »
There are only 2 ways to settle the gravity question.  One is build a test station and spin up to your required G level and the other is put feet on Mars.

The first is probably more versatile in that the same unit can provide data on any required gravity while the second will provide real life science, work and discovery as well as being a hell of a lot more interesting.

BUT...  we can go on and on as we have before in different threads...

Mick.

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #12 on: 08/20/2011 12:50 AM »
Planetary surfaces like Mars, definitely.

Confident start

Quote
You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot),

 NEO's also have a huge amount of mass relative to the needs of foreseeable space industry, and it's likely we'll find NEO's easier to get to and from than Mars.
Quote
you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet,

Mars atmosphere, while better than nothing, isn't itself likely to be enough shielding for long term habitation, shelters will still be needed, possibly thick walled houses will be enough in themselves, but a similar system of using mass to stop radiation works as well in space.

Quote
you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc),
NEO's also are believed to contain water, I suspect chemical properties will be more important to plants than the physical properties of the growth medium, roots are remarkably adept at growing around sharp objects, and there are recent and coarse volcanic soils on Earth that make excellent farming soil.
Quote
the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

This warming of Mars while possible, is not a cheap or simple task, and would bring its own challenges; subsidence of land over permifrost, increased dust storms, less surface light.

Quote
All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Once you've captured your NEO's they are at rest with respect to you, and the lower gravity makes their disassembly easier. (it has occured to me that dust from this could be a major problem, to avoid creating a mini nebula, each NEO might need to be bagged - which could actually help in the recovery of volatiles).
« Last Edit: 08/20/2011 01:12 AM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #13 on: 08/20/2011 01:09 AM »
The surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?

Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that  Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.

As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline MickQ

  • Full Member
  • ****
  • Posts: 503
  • Australia.
  • Liked: 52
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #14 on: 08/20/2011 01:13 AM »
The surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?

Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that  Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.

As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.

This we won't know for sure until we go there with a pick and shovel.

Mick.

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #15 on: 08/20/2011 01:16 AM »
The surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?

Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that  Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.

As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.

This we won't know for sure until we go there with a pick and shovel.

Mick.

I'm betting that, as would be expected, any heavy metal riches have sunk to the planets core.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline MickQ

  • Full Member
  • ****
  • Posts: 503
  • Australia.
  • Liked: 52
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #16 on: 08/20/2011 01:27 AM »
The surface of Mars is (as is often pointed out) less hospitable than the middle of the Sahara, or the middle of the Antarctic icecap. Now, we could build huge rich cities in both of these places if there's an economically recoverable resource to be had, is that the case on Mars?

Mars I think, offers far less in the way of resources that the Earth, and that's across the board, if there was some individual resource there that  Earth doesn't have, or couldn't recover as cheaply, Mars could boom, I can't think of anything.

As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth, I think it's these differences to Earth rather than the similarities of other planets to Earth that are the key to space colonization.

This we won't know for sure until we go there with a pick and shovel.

Mick.

I'm betting that, as would be expected, any heavy metal riches have sunk to the planets core.

Andrew.  I would me much more than happy to confirm that in person for you.  Transport and accomodation will be up to you though.

Mick.

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #17 on: 08/20/2011 01:35 AM »
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline MickQ

  • Full Member
  • ****
  • Posts: 503
  • Australia.
  • Liked: 52
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #18 on: 08/20/2011 02:19 AM »
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?

Peace and quiet springs to mind.

Back to the OP.  If "Building" means the construction of infrastructure then you cannot beat a planetary surface for the sole fact that the human species evolved and grew in gravity.  That is what we know and live with every day.  If, on the other hand, you mean growth and profitability then I think that would depend on the type of business being "Built ".

Mick.

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #19 on: 08/20/2011 02:43 AM »
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?

A resource that can be found on Mars that cannot be obtained on Earth at a lower costs: land that does not belong to any government, and is safe from sovereign intervention.

As for the need for this "resource":

A week ago I heard about some millionaires giving money to a group planing to found an independent libertarian floating island society.  (Insert Andrew Ryan joke here) And if one of these "plans" has surfaced to my attention un-looked for, there must be many groups that wish to found their own society according to their own rules, and could take advantage of this resource Mars has to offer.
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #20 on: 08/20/2011 03:06 AM »
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?

A resource that can be found on Mars that cannot be obtained on Earth at a lower costs: land that does not belong to any government, and is safe from sovereign intervention.

As for the need for this "resource":

A week ago I heard about some millionaires giving money to a group planing to found an independent libertarian floating island society.  (Insert Andrew Ryan joke here) And if one of these "plans" has surfaced to my attention un-looked for, there must be many groups that wish to found their own society according to their own rules, and could take advantage of this resource Mars has to offer.

But haven't you just refuted your own claim that land cannot be obtained on Earth that does not belong to any government by pointing out that floating islands can be constructed at sea that do meet that criteria?
« Last Edit: 08/20/2011 03:10 AM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #21 on: 08/20/2011 03:18 AM »
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?

Peace and quiet springs to mind.

Back to the OP.  If "Building" means the construction of infrastructure then you cannot beat a planetary surface for the sole fact that the human species evolved and grew in gravity.  That is what we know and live with every day.  If, on the other hand, you mean growth and profitability then I think that would depend on the type of business being "Built ".

Mick.

Mick, I think natural gravity sucks! Far better off with the artificial gravity of a rotating habitat, have it as weak or strong as you like. Heck, you can even have a lower gravity in the attic while you have higher gravity in the basement, or have it lower in the morning and higher at night. Whatever rocks your boat!
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Warren Platts

I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?

Peace and quiet springs to mind.

Back to the OP.  If "Building" means the construction of infrastructure then you cannot beat a planetary surface for the sole fact that the human species evolved and grew in gravity.  That is what we know and live with every day.  If, on the other hand, you mean growth and profitability then I think that would depend on the type of business being "Built ".

Mick.

Mick, I think natural gravity sucks! Far better off with the artificial gravity of a rotating habitat, have it as weak or strong as you like. Heck, you can even have a lower gravity in the attic while you have higher gravity in the basement, or have it lower in the morning and higher at night. Whatever rocks your boat!

The problem is, you'll still need to build industry on planetary surfaces, unless you can figure out a way to convert solar energy into matter....

Thus, you're not gaining anything by moving your industry off the surface.

Since space transportation is so expensive, it doesn't make sense to ship unrefined raw materials. Therefore, you're stuck with industry on planetary surfaces.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline DarkenedOne

  • Full Member
  • ****
  • Posts: 953
  • Liked: 56
  • Likes Given: 8
Re: Which is easier, building industry on planets, or in space?
« Reply #23 on: 08/20/2011 06:44 PM »
The problem is, you'll still need to build industry on planetary surfaces, unless you can figure out a way to convert solar energy into matter....

Thus, you're not gaining anything by moving your industry off the surface.

Since space transportation is so expensive, it doesn't make sense to ship unrefined raw materials. Therefore, you're stuck with industry on planetary surfaces.

It will always be most efficient to have refine raw materials as close to their source as possible.  If one is getting a resource on Mars then it makes sense to refine it there.

However the same goes for asteroids.  Asteroids have many heavy elements in far greater abundance than planet surfaces.  Iridium for example is 1000 times more prevalent in asteroids than it is on Earth.  Gold, Uranium, and etc are likely going to come from asteroids.

However the thing is that mining and refining machines do not necessarily require gravity, whereas people do. 
« Last Edit: 08/20/2011 06:45 PM by DarkenedOne »

Offline Warren Platts

The problem is, you'll still need to build industry on planetary surfaces, unless you can figure out a way to convert solar energy into matter....

Thus, you're not gaining anything by moving your industry off the surface.

Since space transportation is so expensive, it doesn't make sense to ship unrefined raw materials. Therefore, you're stuck with industry on planetary surfaces.

It will always be most efficient to have refine raw materials as close to their source as possible.  If one is getting a resource on Mars then it makes sense to refine it there.

However the same goes for asteroids.  Asteroids have many heavy elements in far greater abundance than planet surfaces.  Iridium for example is 1000 times more prevalent in asteroids than it is on Earth.  Gold, Uranium, and etc are likely going to come from asteroids.

There's no evidence whatsoever that gold and uranium etc. are likely going to be found in higher concentrations than the Earth's or Moon's or Mars' crusts.

Quote
However the thing is that mining and refining machines do not necessarily require gravity, whereas people do. 

Planets have gravity. It helps with the plumbing. Whether people require gravity or not isn't the thread topic, but if I was an old lady with osteoporosis and heart trouble, 1/6 g or zero-g would probably result in an improvement in living circumstances.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #25 on: 08/20/2011 07:31 PM »
However the thing is that mining and refining machines do not necessarily require gravity, whereas people do. 

Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #26 on: 08/20/2011 08:18 PM »
There's no evidence whatsoever that gold and uranium etc. are likely going to be found in higher concentrations than the Earth's or Moon's or Mars' crusts.

I thought is had been established through examining meteorites that some asteroids do have exceptionally high concentrations of these elements. 

However the thing is that mining and refining machines do not necessarily require gravity, whereas people do. 

Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

I don't think space industry would be practical without artificial gravity, but I don't see providing it as an obstacle.

« Last Edit: 08/21/2011 01:34 AM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline UncleMatt

  • Member
  • Posts: 15
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #27 on: 08/20/2011 10:46 PM »
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #28 on: 08/20/2011 11:46 PM »
A week ago I heard about some millionaires giving money to a group planing to found an independent libertarian floating island society.

I believe you're talking about Peter Thiel

He founded Paypal. And he's an early investor in Facebook. So I'd expect he's a multi-billionaire.

There's a Seasteading website. That website has a forum.

At this point, NASA human spaceflight seems preoccupied with building large rockets to nowhere. On the other hand NOAA seems to be investing in advancing the state of the art for telerobotics. Since I believe telerobotics and ISRU are better investments to move space settlement forward, I favor NOAA funding over NASA funding.

To get back to the topic of the thread, I believe building industry on the sea and on the moon's surface is easier than building industry on asteroids.

However building industry on asteroids is less implausible than building industry on Mars.



« Last Edit: 08/20/2011 11:47 PM by Hop_David »

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5155
  • Liked: 981
  • Likes Given: 343
Re: Which is easier, building industry on planets, or in space?
« Reply #29 on: 08/21/2011 05:39 AM »
There are only 2 ways to settle the gravity question.  One is build a test station and spin up to your required G level and the other is put feet on Mars.

Actually there are cheaper ways to make leaps of progress. Like http://en.wikipedia.org/wiki/Mars_Gravity_Biosatellite

Or landing mice on moon/mars and keeping them alive long enough.
Orion - the first and only manned not-too-deep-space craft

Offline DLR

  • Full Member
  • ****
  • Posts: 497
  • Liked: 16
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #30 on: 08/21/2011 11:05 AM »
Planetary surfaces, because space is just vacuum. On planetary surfaces, you have everything available where you need it and construction should also be easier (look at what a pain it was to bolt the ISS together ;))

As for gravity, we don't know whether humans require 1g. There's simply no data on that. I may even be that a low-g (not zero-g) environment is beneficial to human health and longevity because reduced gravity also means reduced strain on bones, joints and muscles (such as the heart).

Offline Warren Platts

There's no evidence whatsoever that gold and uranium etc. are likely going to be found in higher concentrations than the Earth's or Moon's or Mars' crusts.

I thought is had been established through examining meteorites that some asteroids do have exceptionally high concentrations of these elements.

Not gold and uranium. I've looked extensively WRT gold, and it appears that gold is only found in minute quantities in meteorites. The reference below from the 1930's has the highest concentrations I've been able to find, and even its results are ambiguous.

http://www.minsocam.org/ammin/AM19/AM19_370.pdf

As for uranium, it is found in meteorites at an average concentration of 0.008 ppm; since it is a so-called lithophile, it gets concentrated in continental crust.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #32 on: 08/21/2011 04:42 PM »
However the same goes for asteroids.  Asteroids have many heavy elements in far greater abundance than planet surfaces.  Iridium for example is 1000 times more prevalent in asteroids than it is on Earth.  Gold, Uranium, and etc are likely going to come from asteroids.

There's no evidence whatsoever that gold and uranium etc. are likely going to be found in higher concentrations than the Earth's or Moon's or Mars' crusts.

This conversation has just freed me of a misconception I've been carrying for years.

I had thought copper, silver and gold were platinum group metals. Some quick Googling has freed me of that error.

How about PGMs in meteorites? Does the premise of Bill White's novel have merit?

I will add my 2¢ -- the moon's low escape velocity can permit meteorites to hit the lunar surface at a lower velocity, allowing some meteorites to remain intact rather than vaporizing. The lack of lunar weather or active geology allows meteorites to remain at the impact site. So if there are asteroids with very valuable ore deposits, it's likely some of these have found their way to the lunar surface over the eons.

Arguments for asteroidal resources are also arguments to do prospecting at the basins of lunar craters.

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #33 on: 08/21/2011 05:04 PM »
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.
That's just plain false. A thick enough atmosphere works just fine for radiation shielding.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #34 on: 08/21/2011 05:07 PM »
There's no evidence whatsoever that gold and uranium etc. are likely going to be found in higher concentrations than the Earth's or Moon's or Mars' crusts.

I thought is had been established through examining meteorites that some asteroids do have exceptionally high concentrations of these elements. 

However the thing is that mining and refining machines do not necessarily require gravity, whereas people do. 

Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

I don't think space industry would be practical without artificial gravity, but I don't see providing it as an obstacle.



Mining an asteroid will have those obstacles

You so easily dismiss anything that does support your POV

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7443
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 163
Re: Which is easier, building industry on planets, or in space?
« Reply #35 on: 08/21/2011 05:24 PM »
Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

Couldn't you use centrifugal settling?
We will be vic-toooooo-ri-ous!!!

Offline Warren Platts

However the same goes for asteroids.  Asteroids have many heavy elements in far greater abundance than planet surfaces.  Iridium for example is 1000 times more prevalent in asteroids than it is on Earth.  Gold, Uranium, and etc are likely going to come from asteroids.

There's no evidence whatsoever that gold and uranium etc. are likely going to be found in higher concentrations than the Earth's or Moon's or Mars' crusts.

This conversation has just freed me of a misconception I've been carrying for years.

I had thought copper, silver and gold were platinum group metals. Some quick Googling has freed me of that error.

How about PGMs in meteorites? Does the premise of Bill White's novel have merit?

I will add my 2¢ -- the moon's low escape velocity can permit meteorites to hit the lunar surface at a lower velocity, allowing some meteorites to remain intact rather than vaporizing. The lack of lunar weather or active geology allows meteorites to remain at the impact site. So if there are asteroids with very valuable ore deposits, it's likely some of these have found their way to the lunar surface over the eons.

Arguments for asteroidal resources are also arguments to do prospecting at the basins of lunar craters.

All over the internet, I keep running into this figure of "up to 100 ppm", which is apparently for all six PGM metals, and not just Pt. (Conveniently, ppm translates directly to "grams per tonne".) There are impact deposits on Earth e.g. in Canada and South Africa, but the concentrations when mining don't often get better than 5 grams per tonne for platinum itself. The following reference looked at 24 iron meteorites and the metal fraction of 5 stony meteorites: the average concentration from an actual meteorite found on Earth is around 11 grams per tonne, with the range being 0.5 to 29.3 grams per tonne.

http://authors.library.caltech.edu/8787/1/NICprl62.pdf

So as to the premise of Platinum Moon, I can't really see it being economically viable. Realistically, you need to be grossing on the order of $10B/year at least. If the price were to get up to $100,000/kg, then you'd need to recover (and refine!) 100,000 kg of platinum.

Thus, a chunk of meteorite at the maximum level of plausibility might consist of 100 gm of Pt/tonne, thus for one year's production, it would have to be 1,000,000 tonne chunck of meteorite. The kinetic energy of such a big rock must be huge, so it's going to hard to find such a large meteorite in tact. Thus, you'll be reduced to running all over the place trying to find and then transport much smaller chunks.

So in reality, you'll be going for conventional deposits where the ore is concentrated as a result of an impact, but you're not really mining visibly large chunks of meteorite.  Thus the Lunar platinum deposits could be expected to be similar in concentration to Earth deposits, although they may be easier to find and more of them due to the lack of erosion on the Moon. So then you're back to 10 grams per tonne, and so to get 100 tonnes of Pt, you'll have to mine and process 10 million tonnes of rock. This would be about 3.3 cubic kilometers of feedstock. Per year.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Warren Platts

Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

Couldn't you use centrifugal settling?

When mining a practically weightless asteroid? Centrifugal forces will only make it harder to find a purchase on the asteroid, and it would likely cause the asteroid to fly apart if you spin it too much.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #38 on: 08/21/2011 06:35 PM »
The kinetic energy of such a big rock must be huge, so it's going to hard to find such a large meteorite in tact. Thus, you'll be reduced to running all over the place trying to find and then transport much smaller chunks.

Kinetic energy from an impact can take different forms. Shockwaves through the lunar crust. Thermal energy. Ejecta from the impact will have it's velocity and thus its 1/2 mv^2.

But the kinetic energy per gram relies only on velocity. 1/2 m * v^2. It seems to me two meteorites of different mass traveling at the same speed would acquire the same calories per gram.

The impact speed would be sqrt(Vesc^2 + Vinf^2). Lunar escape on the moon's surface is about 2.4 km/sec. So, depending on Vinf, impact could be as slow as 2.4 km/sec.

To be honest, I don't know if that's slow enough to let a metallic meteorite remain intact.

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #39 on: 08/21/2011 06:42 PM »
Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

Couldn't you use centrifugal settling?

When mining a practically weightless asteroid? Centrifugal forces will only make it harder to find a purchase on the asteroid, and it would likely cause the asteroid to fly apart if you spin it too much.

I believe Martijn is thinking of a centrifuge apart from the asteroid rather than spinning the entire body.

A sluice box as well as other gravity dependent mining processes might be done on such a centrifuge.

However, as Jim points out, a lot of the excavation and transportation methods also rely on gravity. Getting the ore to the centrifuge will require invention of new processes.

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #40 on: 08/21/2011 07:17 PM »
I'd be happy to send you to Mars Mick, but I'll at least need some indication that there's a possibility of untold mineral wealth before we put feet on the ground, even if Mars is littered with gold, even at it's heady price these days, we probably wouldn't cover the costs. We need something there that cannot be obtained on Earth at a lower cost, anything spring to mind?

A resource that can be found on Mars that cannot be obtained on Earth at a lower costs: land that does not belong to any government, and is safe from sovereign intervention.

As for the need for this "resource":

A week ago I heard about some millionaires giving money to a group planing to found an independent libertarian floating island society.  (Insert Andrew Ryan joke here) And if one of these "plans" has surfaced to my attention un-looked for, there must be many groups that wish to found their own society according to their own rules, and could take advantage of this resource Mars has to offer.

But haven't you just refuted your own claim that land cannot be obtained on Earth that does not belong to any government by pointing out that floating islands can be constructed at sea that do meet that criteria?

".. and safe from sovereign intervention."  If worst comes to worst a floating island can be sunk by any number of nation less than ninety minuets after the decision to do so is made.
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #41 on: 08/21/2011 07:26 PM »
Isn't it obvious that you dock your rotating processing facility to one of the poles of the asteroid and use excavators to dump the raw material straight from the asteroid into the hopper, which is an open topped donut around the hub of the processing facility?

According to Wiki:
Quote
In fact, all the gold, cobalt, iron, manganese, molybdenum, nickel, osmium, palladium, platinum, rhenium, rhodium and ruthenium that we now mine from the Earth's crust, and that are essential for economic and technological progress, came originally from the rain of asteroids that hit the Earth after the crust cooled.[2][3] This is because, while asteroids and the Earth congealed from the same starting materials, Earth's massive gravity pulled all such siderophilic (iron loving) elements into the planet's core during its molten youth more than four billion years ago. Initially, this left the crust utterly depleted of such valuable elements. Asteroid impacts re-infused the depleted crust with metals.
http://en.wikipedia.org/wiki/Asteroid_mining
« Last Edit: 08/21/2011 08:34 PM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #42 on: 08/21/2011 07:36 PM »
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.
That's just plain false. A thick enough atmosphere works just fine for radiation shielding.

Depends on the radiation.  Some kinds of "cannonball" cosmic radiation can strike atmospheric molecules and cause a shotgun blast of secondary fragments to scatter down in a cone spreading out from the original path of the primary particle.  This extra atomic shrapnel can cause more damage to humans and their machines than if there had been no atmosphere at all.  Probably only Venus/ gas giant atmospheric densities can effectively block this radiation.

However these particles can be deflected by a magnetic field because they are composed of atomic nuclei and have a charge.

Another thing about wanting a magnetic field: these charged particles (usually from the sun) eventually break down all atmospheric molecules and boost their energy levels to such a state that they escape into space, depleting the atmosphere completely.  This process has already happened to Mars (time scales of 100k years or more).  Any Terra-forming project will have to counter act this long term atmospheric bleed off.  UncleMatt is correct.  But with Terra-forming erra technology it should be possible to construct an equatorial superconducting cable and power it up with solar power to give Mars an adequate magnetic field.
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7443
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 163
Re: Which is easier, building industry on planets, or in space?
« Reply #43 on: 08/21/2011 08:24 PM »
I believe Martijn is thinking of a centrifuge apart from the asteroid rather than spinning the entire body.

Yeah, that's what I meant. There's a web site out there with ideas about asteroid mining and I think they proposed this. I can't remember the name though.
We will be vic-toooooo-ri-ous!!!

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #44 on: 08/22/2011 04:29 AM »
Yes, they do.  For transport (to stay in buckets or conveyers) or for settling

Couldn't you use centrifugal settling?

When mining a practically weightless asteroid? Centrifugal forces will only make it harder to find a purchase on the asteroid, and it would likely cause the asteroid to fly apart if you spin it too much.

I believe Martijn is thinking of a centrifuge apart from the asteroid rather than spinning the entire body.

A sluice box as well as other gravity dependent mining processes might be done on such a centrifuge.

However, as Jim points out, a lot of the excavation and transportation methods also rely on gravity. Getting the ore to the centrifuge will require invention of new processes.

I think zero gravity ore movement will be like power beaming, but with mass.  A catcher funnel at a refinery base station tracks the mining machine, while the mining machine uses some version of an auto tennis ball serving machine to hurl continuous stream of ore towards the funnel.  The velocities do not have to be fast at all.  If the velocities are slow enough, one could take advantage of the asteroid's small gravity to aim the mass stream on a parabolic trajectory to deal with line of sight issues.

A juiced up version of this mining device throwing ore into space above local escape velocity would be all that is needed to change an asteroid's course for any planetary protection missions.
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #45 on: 08/22/2011 12:27 PM »
First, how does the mining handle (extract) the ore before it sending it to the refinery?  Excavators won't work, no traction and lifting the bucket could put the contents into orbit.
The next thing, how is the ore handled within the refinery?
« Last Edit: 08/22/2011 12:30 PM by Jim »

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7443
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 163
Re: Which is easier, building industry on planets, or in space?
« Reply #46 on: 08/22/2011 12:36 PM »
First, how does the mining handle (extract) the ore before it sending it to the refinery?  Excavators won't work, no traction and lifting the bucket could put the contents into orbit.

By melting and compacting the regolith to a depth of several meters or more and establishing a stable platform that way?

Quote
The next thing, how is the ore handled within the refinery?

By slowly rotating the refinery?
We will be vic-toooooo-ri-ous!!!

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7443
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 163
Re: Which is easier, building industry on planets, or in space?
« Reply #47 on: 08/22/2011 12:39 PM »
Ah, found the website I was looking for:

http://www.permanent.com/
We will be vic-toooooo-ri-ous!!!

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #48 on: 08/22/2011 01:52 PM »
Since 1g gravity is required to long term habitation, the only acceptable location for permanent human presence in space is on space stations.     

Prove it.

I see that you're not obliquely suggesting that the idea: "since no gravity whatsoever is required for a permanent human presence in space, humans could live anywhere" need be accepted without proof.

We do know that humans can permanently live in a one gee environment.  I believe we will have to discover the answer to human hab on Mars or the Moon by doing.  If the partial gravity has a long term detriment, then crew rotations to a one gee ring station could provide a health benefit.

As I've mentioned, free floating colonies mining NEO's can offer several resources that don't exist on Earth...

Maybe they can, but do you have some documentation on which of these resources would be of great benefit?  True, we should study and prospect NEO's in greater detail, at the right time, but that time is not now.

However the thing is that mining and refining machines do not necessarily require gravity, whereas people do.

That is true in principle, but a mining machine on an asteroid will have to attach itself to the asteroid, mine for a bit, then reattach itself and so on.  It would be a difficult problem to solve, from a pragmatic viewpoint.  Buckets could be covered, and settling could be accomplished by a centrifugal system, but it would be complex.

When the concentrations appear to be grams of metal per tonne of slag, it seems highly unlikely that mining will be economically worthwhile for many a year.

I had an interesting image of the asteroid belt being turned into a dust belt of small ground up particles.  Probably turn into a ring around the Sun.  If JWST could find such a dust belt surrounding a distant star, it could suggest an intelligent life form has mined their asteroid belt.  I don't know how common asteroid belts are, however.
Sometimes I just flat out don't get it.

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #49 on: 08/22/2011 05:56 PM »
Since 1g gravity is required to long term habitation,

Since you state your unsubstantiated speculation as fact, you are not credible.

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #50 on: 08/22/2011 05:59 PM »
Isn't it obvious that you dock your rotating processing facility to one of the poles of the asteroid

If the asteroid is tumbling, it may not have a defined pole.

and use excavators

Existing excavation as well as transportation methods rely on gravity.

So how are you getting the ore to the rotating facility?

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #51 on: 08/22/2011 06:26 PM »
I think zero gravity ore movement will be like power beaming, but with mass.  A catcher funnel at a refinery base station tracks the mining machine,

When I pour into a funnel, I'm using a gravity. Funnels won't work as well without gravity.

while the mining machine uses some version of an auto tennis ball serving machine to hurl continuous stream of ore towards the funnel.

If the tennis ball machine isn't anchored, it won't throw well.

How is it anchored to the asteroid?

And the material the tennis ball machine is throwing? How is this material excavated?

From Putting Rotary Drilling Into Perspective "The laws of physics dictate that for every action, there is an equal and opposite reaction, meaning that if you push on the ground with 18,000 kg (40,000 lb), the same force will push back on the unit. There-fore, the weight of the machine must be over 18,000 kg (40,000 lb) at the location of the drill string to avoid the machine “lifting off” the jacks."

Just like virtually every aspect of terrestrial excavation, gravity is also routinely used for drilling.

Digging up the ore, drilling holes, lodging anchor bolts for guy wires -- all this will require inventing and developing new techniques.

And I will once again bring up launch windows. The lower delta V asteroids have more earth like orbits. And the closer the orbital period is to 1 year, the greater the synodic period. For example, an asteroid with 1.1 year orbital period would have synodic period: (1.1 * 1) / (1.1 - 1) or 11 years. A launch window each 11 years.

How many missions would it take to establish infrastructure? Five missions would mean 55 years.

And there's trip time. Most Hohmann like orbits take around 6 or 7 months. This makes it a lot harder to send humans. Teleoperation is also very difficult as an asteroid is often 1 or 2 A.U. from earth -- that makes a light lag of 20 to 40 minutes. And those distances also make high bandwidth more difficult.

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #52 on: 08/22/2011 07:05 PM »
Hop David gives the best explanation ever on the difficulties of mining NEO's: gravity. 

Search this site for the term "gravity well".  One will find any number of explanations why NEO's are so great, when defined by the shallow gravity well which isone of their main characteristics.  As is obvious, a shallow gravity well is but one advantage among many.  It would be very rare circumstances where the gravity well would become the main parameter in a mission design.

If we plan to colonize the nearby worlds, mass and gravity will all be an essential part of the economic equation.  And mining will also be the fundamental economic engine for the long haul, umpteen decades or centuries from now.  Mining in any way, shape or form, will involve the handling of a great deal of mass.

So, if you're going to mine a homogenous NEO, I think you had better be prepared to capture the entire thing with a net which is attached to the drilling/benificiation rig.  You'd eventually grind the whole thing up, distrubuting a "slag heap" in some kind of orbit approximating the orbit of the original body.  I'm thinking that you would throw the slag "downwind", so to speak; your NEO would gradually get faster as it got lighter, and you wouldn't be hit in the "windshield" by your slag.

As these objects got jostled around, some of them would escape, and head towards the Earth, adding to the space junk already in orbit, and complicating its mitigation to no end.  Each particle would have its own orbit and trajectory; perhaps their average size would be that of #57 gravel; it would be a nightmare to have to deal with it; and the damage caused could be far more than current shielding can resist.
Sometimes I just flat out don't get it.

Offline Hells

  • Member
  • Posts: 13
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #53 on: 08/22/2011 07:47 PM »
Slam high-value bodies into the same spot on mars repeatedly. The content will liquefy and form into high grade deposits, which you can then begin to excavate after it's cooled. Will only require a minor breakthrough in propulsion    :-*

Offline savuporo

  • Senior Member
  • *****
  • Posts: 5155
  • Liked: 981
  • Likes Given: 343
Re: Which is easier, building industry on planets, or in space?
« Reply #54 on: 08/22/2011 08:30 PM »
We do know that humans can permanently live in a one gee environment.  I believe we will have to discover the answer to human hab on Mars or the Moon by doing.
Once again, you don't have to experiment with humans to figure the partial gravity question out to a reasonable confidence degree ..
In fact, IMO it would be pretty irresponsible to test on humans first.
Orion - the first and only manned not-too-deep-space craft

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #55 on: 08/22/2011 08:53 PM »
You start by assembling the Processing Shack in LEO, it could be a tidy wheel design or a more complicated geometry, either way it can spin to provide gravity for the various processes where it's needed.

This Processing Shack would weigh in the thousands of tonnes and would be fitted with everything needed for mining an NEO.

Arriving at the NEO it would anchor at one of the poles and drill towards the NEO's core, a bag would be placed around the NEO to capture any debris released, the bag could act as a heat trap to encourage the release and enable the capture of volatile.

With the NEO bagged and secured the processing of the NEO could begin, the Processing Shack would be spun up to speed rotating in the same direction as the NEO, by pushing against the NEO's rotation while doing this the NEO's rate of rotation would be slowed.

The excavation process would start around the trunk that was drilled deep into the NEO, this could be done either with lidded excavator buckets, or auger, or (more likely) bucket wheel excavators, these would be anchored to the trunk of the Processing Shack which itself would just be an extension of the Shacks hub.

The trunk would be a substantial structure, meters in diameter an allow operations deep inside the NEO, including extracting volatiles and if necessary, radiation shelter for the crew.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #56 on: 08/22/2011 08:58 PM »
I don't get this debate over how many gee's humans need, if we must have a full gee (which I doubt) whether in space, or on the Moon, or on Mars you can have a full gee, the engineering might be a little trickier in a stronger planetary gravity, but we're still just talking about big carousels.
« Last Edit: 08/22/2011 09:47 PM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7443
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 163
Re: Which is easier, building industry on planets, or in space?
« Reply #57 on: 08/22/2011 09:00 PM »
Arriving at the NEO it would anchor at one of the poles and drill towards the NEO's core, a bag would be placed around the NEO to capture any debris released, the bag could act as a heat trap to encourage the release and enable the capture of volatile.

Both anchoring and drilling could be difficult on a rubble pile, which is why I was thinking of melting your way towards the core. Maybe epoxy or even water would work too.
We will be vic-toooooo-ri-ous!!!

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #58 on: 08/22/2011 09:11 PM »
Arriving at the NEO it would anchor at one of the poles and drill towards the NEO's core, a bag would be placed around the NEO to capture any debris released, the bag could act as a heat trap to encourage the release and enable the capture of volatile.

Both anchoring and drilling could be difficult on a rubble pile, which is why I was thinking of melting your way towards the core. Maybe epoxy or even water would work too.

You have the weight and angular inertial of the Processing Shack on the drill, even at one hundred thousandth of a gee that's tens of kilos, you can start with a small pilot hole and several small anchoring holes to get a grip.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Warren Platts

Arriving at the NEO it would anchor at one of the poles and drill towards the NEO's core, a bag would be placed around the NEO to capture any debris released, the bag could act as a heat trap to encourage the release and enable the capture of volatile.

Both anchoring and drilling could be difficult on a rubble pile, which is why I was thinking of melting your way towards the core. Maybe epoxy or even water would work too.

Or you can go to the Moon instead....
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7443
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 163
Re: Which is easier, building industry on planets, or in space?
« Reply #60 on: 08/22/2011 10:07 PM »
Or you can go to the Moon instead....

I'm not saying you shouldn't. Asteroid mining is still interesting even if you do.
We will be vic-toooooo-ri-ous!!!

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #61 on: 08/22/2011 10:18 PM »
Arriving at the NEO it would anchor at one of the poles and drill towards the NEO's core, a bag would be placed around the NEO to capture any debris released, the bag could act as a heat trap to encourage the release and enable the capture of volatile.

Both anchoring and drilling could be difficult on a rubble pile, which is why I was thinking of melting your way towards the core. Maybe epoxy or even water would work too.

Or you can go to the Moon instead....

Whereupon you immediately have the disadvantage of the month long day-night cycle, and not having zero gee when it's useful.
« Last Edit: 08/22/2011 11:29 PM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #62 on: 08/23/2011 04:25 AM »
This Processing Shack would weigh in the thousands of tonnes and would be fitted with everything needed for mining an NEO.

And to get from LEO to the asteroid, you'd also need thousands of tonnes of propellant.

To put this in perspective, the I.S.S. masses about 420 tonnes.

You're talking science fiction here, not something plausible.

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #63 on: 08/23/2011 04:27 AM »
Whereupon you immediately have the disadvantage of the month long day-night cycle

Not necessarily.

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #64 on: 08/23/2011 05:28 AM »
This Processing Shack would weigh in the thousands of tonnes and would be fitted with everything needed for mining an NEO.

And to get from LEO to the asteroid, you'd also need thousands of tonnes of propellant.

To put this in perspective, the I.S.S. masses about 420 tonnes.

You're talking science fiction here, not something plausible.

Well if you're saying that less plant mass would be required for industrial activities if those activities were based on the Moon or on Mars you'll have to provide reasons supporting that theory, and however much propellant you need to burn to get to the more accessible NEO's you'll have to burn more to land on the Moon or Mars, and those landings are likely to require the assembly of the processing facility after landing the bits at the destination rather than in LEO.

Even at the Moons polar region you have the month long day-night cycle, you have peaks where that cycle is mostly day, but you still get some night, you're restricted to a tiny fraction of the Moons total surface area, and you have to track the sun through 360 degrees.
« Last Edit: 08/23/2011 05:41 AM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #65 on: 08/23/2011 09:00 AM »

Even at the Moons polar region you have the month long day-night cycle, you have peaks where that cycle is mostly day, but you still get some night, you're restricted to a tiny fraction of the Moons total surface area, and you have to track the sun through 360 degrees.

There is nuclear power options.

Offline Tass

  • Full Member
  • ***
  • Posts: 361
  • Liked: 76
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #66 on: 08/23/2011 11:12 AM »
Isn't it obvious that you dock your rotating processing facility to one of the poles of the asteroid

If the asteroid is tumbling, it may not have a defined pole.

What do you mean "tumbling". Everything that rotates have a pole unless it is under continual torque. As long as it is away from strong tidal fields there is no "tumbling" just rotating.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #67 on: 08/23/2011 11:22 AM »
Isn't it obvious that you dock your rotating processing facility to one of the poles of the asteroid

If the asteroid is tumbling, it may not have a defined pole.

What do you mean "tumbling". Everything that rotates have a pole unless it is under continual torque. As long as it is away from strong tidal fields there is no "tumbling" just rotating.

Not true,  the axis of rotation could be rotating on another axis (two axis of rotation) which is tumbling.

An example
http://en.wikipedia.org/wiki/Precession
« Last Edit: 08/23/2011 11:27 AM by Jim »

Offline Tass

  • Full Member
  • ***
  • Posts: 361
  • Liked: 76
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #68 on: 08/23/2011 12:36 PM »
Isn't it obvious that you dock your rotating processing facility to one of the poles of the asteroid

If the asteroid is tumbling, it may not have a defined pole.

What do you mean "tumbling". Everything that rotates have a pole unless it is under continual torque. As long as it is away from strong tidal fields there is no "tumbling" just rotating.

Not true,  the axis of rotation could be rotating on another axis (two axis of rotation) which is tumbling.

An example
http://en.wikipedia.org/wiki/Precession


Well yes if it is small enough to be considered perfectly rigid and very asymmetric.
« Last Edit: 08/23/2011 12:41 PM by Tass »

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #69 on: 08/23/2011 12:46 PM »
Isn't it obvious that you dock your rotating processing facility to one of the poles of the asteroid

If the asteroid is tumbling, it may not have a defined pole.

What do you mean "tumbling". Everything that rotates have a pole unless it is under continual torque. As long as it is away from strong tidal fields there is no "tumbling" just rotating.

Not true,  the axis of rotation could be rotating on another axis (two axis of rotation) which is tumbling.

An example
http://en.wikipedia.org/wiki/Precession


Yes. In the presence of a torque.

While there would be no external gravity field to provide the torque that causes precession in spinning objects on earth, any change to the asteroid's inertia tensor combined with inevitable frictional dissipation will cause the axis of rotation to change over time.  See the mechanism behind true polar wander: in a dissipating body the axis of rotation will seek the axis of maximum rotational inertia.

This will mean that you have to mine the asteroid in a rotationally symmetric manner to keep the original rotation pole where you docked your processor stable.
« Last Edit: 08/23/2011 12:47 PM by LegendCJS »
Remember: if we want this whole space thing to work out we have to optimize for cost!

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #70 on: 08/23/2011 06:52 PM »
I wasn't referring to precession, just the gif in the link.

Tass, size has nothing to do with it.  Any object can tumble.

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #71 on: 08/23/2011 06:59 PM »
I wasn't referring to precession, just the gif in the link.

Tass, size has nothing to do with it.  Any object can tumble.

You have to have precession for "tumbling" to happen, and for there to be precession you have to have a force being applied.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #72 on: 08/23/2011 07:05 PM »
I wasn't referring to precession, just the gif in the link.

Tass, size has nothing to do with it.  Any object can tumble.

You have to have precession for "tumbling" to happen, and for there to be precession you have to have a force being applied.

Not true, there are other events like collision or outgasing that can cause a tumble and  precession is not involved.

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #73 on: 08/23/2011 08:17 PM »
Either way Jim, a force has to be applied to change the axis of rotation.
« Last Edit: 08/23/2011 08:29 PM by Andrew_W »
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #74 on: 08/23/2011 10:13 PM »
Either way Jim, a force has to be applied to change the axis of rotation.

No, the origin point is that NEOs can be tumbling and that there is not a single axis of rotation

Offline Andrew_W

  • Full Member
  • ****
  • Posts: 769
  • Rotorua, New Zealand
    • Profiles of our future in space
  • Liked: 14
  • Likes Given: 12
Re: Which is easier, building industry on planets, or in space?
« Reply #75 on: 08/23/2011 10:17 PM »
Either way Jim, a force has to be applied to change the axis of rotation.

No, the origin point is that NEOs can be tumbling and that there is not a single axis of rotation

Simply wrong.
I confess that in 1901 I said to my brother Orville that man would not fly for fifty years.
Wilbur Wright

Offline KelvinZero

  • Senior Member
  • *****
  • Posts: 3611
  • Liked: 513
  • Likes Given: 130
Re: Which is easier, building industry on planets, or in space?
« Reply #76 on: 08/23/2011 10:36 PM »
Either way Jim, a force has to be applied to change the axis of rotation.
This would probably be better moved to a question answer thread. Jim is probably right. My guess is that any body does have a total angular momentum that can be expressed as a vector and a magnitude, but this vector is fixed in worldspace, not wrt the body. I just had a quick experiment with a pencil.. with some nimble fingerwork I can throw it in the air with a fast rotation along its axis and a slow rotation end over end.. No part of the pencil seems to be a consistant polar region.

ps im not sure about that total momentum thing. true or not?
« Last Edit: 08/23/2011 10:44 PM by KelvinZero »

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #77 on: 08/23/2011 10:40 PM »
Either way Jim, a force has to be applied to change the axis of rotation.

No, the origin point is that NEOs can be tumbling and that there is not a single axis of rotation

Simply wrong.

Prove it

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #78 on: 08/23/2011 11:36 PM »
Either way Jim, a force has to be applied to change the axis of rotation.

No, the origin point is that NEOs can be tumbling and that there is not a single axis of rotation

Simply wrong.

Prove it
Only perfectly rigid bodies have two stable rotation axes. NEOs are not perfectly rigid over long periods of time, and thus they only have one stable axis of rotation, generally the axis of rotation where rotational kinetic energy is minimized (though angular momentum stays the same).

Over short periods of time, a NEO might have two stable axes of rotation, because over short periods of time (i.e. if perturbations occur frequently and strongly enough), a NEO might approximate a rigid body. But over long periods of time between perturbations, a NEO has only one stable axis of rotation...

Imagine rotating a pencil around its long axis in space. For the same angular momentum, this will allow for higher rotational kinetic energy than if you rotated it along a short axis (i.e. end over end), but since a pencil is not perfectly rigid, some of this rotational kinetic energy is dissipated in friction from flexing of the pencil, and in order to maintain the same angular momentum, eventually the pencil will have to rotate about its short axis, where rotational kinetic energy is at a minimum for a given angular momentum. (EDIT:To add, it seems obvious to me that rotational kinetic energy is not minimized if a free object is tumbling...)

Same thing happens with spacecraft. Explorer 1, for instance, which was launched rotating about its long axis soon ended up rotating about its short axis: http://en.wikipedia.org/wiki/Explorer_1#Results
 (favorite quote from the wikipedia page: "To the surprise of mission experts..." ;) )
« Last Edit: 08/24/2011 12:09 AM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #79 on: 08/23/2011 11:50 PM »
http://echo.jpl.nasa.gov/asteroids/4179_Toutatis/toutatis.html
Quote
Toutatis's Rotation State

Toutatis has one of the strangest rotation states yet observed in the solar system. Instead of the spinning about a single axis as do the planets and the vast majority of asteroids, it "tumbles" somewhat like a football after a botched pass. Its rotation is the result of two different types of motion with periods of 5.4 and 7.3 Earth days that combine in such way that Toutatis's orientation with respect to the solar system never repeats.
So, you're both right. In the vast majority of asteroids, there is a single axis of rotation.

Toutatis is a rare counter-example. It tumbles. (It also has a somewhat chaotic orbit due to gravitational perturbations from Jupiter (et al) that makes predicting its actual location.)
http://csep10.phys.utk.edu/astr161/lect/asteroids/toutspin.mpg
« Last Edit: 08/24/2011 12:15 AM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #80 on: 08/24/2011 12:07 AM »
This Processing Shack would weigh in the thousands of tonnes and would be fitted with everything needed for mining an NEO.

And to get from LEO to the asteroid, you'd also need thousands of tonnes of propellant.

To put this in perspective, the I.S.S. masses about 420 tonnes.

You're talking science fiction here, not something plausible.

Well if you're saying that less plant mass would be required for industrial activities if those activities were based on the Moon or on Mars

Not Mars. I believe NEOs, Phobos and Deimos are more accessible than Mars.

you'll have to provide reasons supporting that theory,

Reasons supporting that theory:

Transporting humans to the moon takes less than a week. To an NEO, 6 months. Transporting humans to the moon is much simpler.

Improved telerobotics has the potential to build lunar infrastructure. Long light lag and low bandwidth precludes use of telerobots on NEOs.

With launch windows every two weeks, multiple missions could be made to the moon in a few years. With the rarity of launch windows to an NEO, multiple missions would likely take the better part of a century. Rarity of launch windows argues for the single huge facility in LEO you call for, but it's not necessary for the moon.

The human has millennia of experience excavating, transporting and refining ore using gravity. Inventing new techniques and acquiring experience for microgravity mining will take time and money.

On the moon, in situ regolith weights can be fashioned to give shovels, drills, etc. more newtons as they press tool to dirt. Even with 1/6 gravity, we can find ways to press hard. No gravity newtons on an asteroid. Unless your shovel is many, many kilograms, pressing tip to asteroid will cause your shovel to go the opposite direction.

On the moon there is very good indication of rich volatile ores at the poles. As yet, we have no inventory of possible asteroidal resources. We still haven't sent out prospecting probes.


you're restricted to a tiny fraction of the Moons total surface area,

I've never grokked the "lunar poles are tiny" argument. You could say Japan, England, Ireland, Hawaii, Sicily are tiny in comparison to the continents. Does that mean they're worthless? Far from it.

And while I've heard Zubrinistas employ this argument, this is the first time I've heard it from an NEO advocate. A little ironic.

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #81 on: 08/24/2011 12:13 AM »
Mars advocates aren't equivalent to Zubrinistas. Just sayin'. ;)
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline KelvinZero

  • Senior Member
  • *****
  • Posts: 3611
  • Liked: 513
  • Likes Given: 130
Re: Which is easier, building industry on planets, or in space?
« Reply #82 on: 08/24/2011 01:08 AM »
Hi Robotbeat,
Thanks for explanation of why asteroids tend to get a well defined pole. This made me think about the parallel streaks we see on some bodies. Could this be from avalanches caused by resettling? How precarious could these rubble piles be?

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #83 on: 08/24/2011 01:50 PM »

Even at the Moons polar region you have the month long day-night cycle, you have peaks where that cycle is mostly day, but you still get some night, you're restricted to a tiny fraction of the Moons total surface area, and you have to track the sun through 360 degrees.

There is nuclear power options.

No, there aren't

Somewhere around here, I have an envelope on which I worked out the various tumbling vectors of each and every asteroid.  Took me about an hour or so...

And the Zubrinistas.  Didn't they gain their independence last year?
« Last Edit: 08/24/2011 02:05 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline DarkenedOne

  • Full Member
  • ****
  • Posts: 953
  • Liked: 56
  • Likes Given: 8
Re: Which is easier, building industry on planets, or in space?
« Reply #84 on: 08/24/2011 02:28 PM »

Even at the Moons polar region you have the month long day-night cycle, you have peaks where that cycle is mostly day, but you still get some night, you're restricted to a tiny fraction of the Moons total surface area, and you have to track the sun through 360 degrees.

There is nuclear power options.

No, there aren't

Somewhere around here, I have an envelope on which I worked out the various tumbling vectors of each and every asteroid.  Took me about an hour or so...

And the Zubrinistas.  Didn't they gain their independence last year?

According to NASA nuclear power is quite doable for the moon.
http://www.space.com/5850-nasa-eyes-nuclear-power-moon-base.html

Offline Tass

  • Full Member
  • ***
  • Posts: 361
  • Liked: 76
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #85 on: 08/24/2011 03:30 PM »
Tass, size has nothing to do with it.  Any object can tumble.

Any object that is either rigid and has different moments of inertia along different axes, or is subjected to a torque.

Big objects are not rigid on geological timescales.

Offline UncleMatt

  • Member
  • Posts: 15
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #86 on: 08/28/2011 12:44 PM »
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.
That's just plain false. A thick enough atmosphere works just fine for radiation shielding.
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #87 on: 08/28/2011 04:46 PM »
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.
That's just plain false. A thick enough atmosphere works just fine for radiation shielding.
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...
It's such an obvious point that finding a direct source that says it explicitly may be difficult. But here's an article on wikipedia: "In passing through matter, fast charged particles ionize the atoms or molecules which they encounter. Thus, the fast particles gradually lose energy in many small steps" http://en.wikipedia.org/wiki/Stopping_power_(particle_radiation)

Magnetic fields are only effective at shielding charged particles, anyways. A thick atmosphere can attenuate UV and some X-ray radiation, as well.

I should know what I'm talking about; I have a Bachelor's of Science degree in physics and am now taking an upper-level course in Space Physics (dealing with space radiation, interaction with planetary magnetic fields, etc).
« Last Edit: 09/02/2011 10:42 PM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Hells

  • Member
  • Posts: 13
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #88 on: 08/28/2011 11:12 PM »
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...

http://en.wikipedia.org/wiki/Magnetosphere

Offline Rhyshaelkan

  • Full Member
  • **
  • Posts: 264
    • PERMANENT Forums
  • Liked: 25
  • Likes Given: 37
Re: Which is easier, building industry on planets, or in space?
« Reply #89 on: 08/29/2011 03:25 AM »
So what we have so far?

1G works for humans. Proof should not be necessary. Micro-g bad for humans. Proof is in the pudding. Fractional-g, inconclusive data. The few days spent on the Moon does not offer enough data. As they spent more time in micro-g transit than the stay itself.

My opinion of this. If there is a definite up and down, most bodily functions will cope nicely. However in fractional-g, there will be muscle loss as there is less resistance. Bone-mass loss seems will be an issue. However less extreme than micro-g. Weight suits might help keep the human body toned. However one would have to readjust constantly when donning or removing said weight suit. Best to keep it on continuously or find an alternative.

An alternative is a decent exercise regimen. This will require gear to provide resistance. Well documented in micro-g. If you could afford the room and water, swimming provides lots of resistance and might be the exercise of choice on fractional-g bodies. Would not have to take up much room, we already have "endless pools" with today's tech. Abundant lunar water might lend itself for a nice psychologically reassuring exercise.

For the original topic. Space itself has no resources from which to draw. We will have to bring something there. Or find the resources elsewhere. A graduated growth program where we build in LEO and then in GEO then at L1 and then at L4 and L5 does not solve the problems of resources. We would be launching everything from Earth. A money and resources sink.

This leads us to astro resources. Mars, Moon, Main Belt Asteroids, Near Earth Asteroids and Objects. As was pointed out before, accessibility might be the deciding factor for where we start.

Asteroids have some of the lowest D-V requirements and a high chance for decent resources from which to build industry. Pick a list of candidates which offer; the best potential for resources, low D-V, and orbital period that allows us to accomplish something meaningful. If the asteroid tumbles? Deal with it. That should be less of a factor than the other points. I will enumerate the solutions at request. However I would think any search savvy person could find why a tumbling or rotating asteroid is a non-factor.

Mars. Everyone's favorite. "We gotta get to Mars." "Mars or bust!"

... ok got too bored to continue. However the Moon is my first choice. As previously noted hydrogen at the poles, and possible other volatiles. Asteroid impacts, possibly a boon in rare elements not found in average lunar samples. Peaks of light. Long day/night cycle allowing someone to keep up with the day/night terminator at a brisk walk. At higher latitudes, even slower than a brisk walk. Proximity for travel and tele-operation.

For the Mars and Asteroid lovers though. I am certainly not saying that the Moon is the end all be all of human expansion into space. I just feel that it should be the first step. Instead of dividing our time and resources scrambling in several directions. We should focus on one and get that industry going to open up the rest of the solar system.

http://www.amazon.com/Welcome-Moonbase-Ben-Bova/dp/0345328590

Dated(1987), but a sad commentary of how human resources have been squandered and unfocused.

The forum for www.PERMANENT.com can be found in my sidebar.

I am an avid fan of the Mark Prados and Paul Spudis(es? Spudii? :D) of this world.
« Last Edit: 08/30/2011 11:52 AM by Rhyshaelkan »
I am not a professional. Just a rational amateur dreaming of mankind exploiting the universe.

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #90 on: 08/29/2011 02:04 PM »
So what we have so far?

1G works for humans. Proof should not be necessary. Micro-g bad for humans. Proof is in the pudding. Fractional-g, inconclusive data. The few days spent on the Moon does not offer enough data. ...

Good introductory remarks, and pretty good analysis too, up to this point:

Quote
Asteroids have some of the lowest D-V requirements and a high chance for decent resources from which to build industry. Pick a list of candidates which offer; the best potential for resources, low D-V, and orbital period that allows us to accomplish something meaningful.

Low gravity, which enables the low delta-vee characteristics, seems to be a large problem with respect to mining as talked about above.  I agree that tumbling itself is a relatively minor issue, if all the other issues have been solved.  It is partly the "picking from a list" aspect which doesn't work for me, from the perspective of my arm chair.  The creation of such a list would require years of robotic prospecting in the first place, and that before the mining and beneficiation and smelting problems could even be solved.

Fortunately, you agree with me, not that agreeing with me is some sort of pre-requisite, that the Moon is the best bet for an intial base.  Mining the asteroids is too far into the future for consideration today.  I continue to be astonished at the hypnotic effect of the far future and its utopian possibilities, which come at the expense of practicable near term possibilities.  The only way that distant future will ever come to be is to begin working with the nearest celestial body that we have to work with.

Besides, who wants to get bogged down on an asteroid?
Sometimes I just flat out don't get it.

Offline Tass

  • Full Member
  • ***
  • Posts: 361
  • Liked: 76
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #91 on: 08/29/2011 02:40 PM »
Besides, who wants to get bogged down on an asteroid?

Not on an asteroid, in a space colony build from asteroid material. I'd sure like to live in an O'Neill cylinder, though I doubt I'll ever get to.

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #92 on: 08/29/2011 05:52 PM »
Besides, who wants to get bogged down on an asteroid?

Not on an asteroid, in a space colony build from asteroid material. I'd sure like to live in an O'Neill cylinder, though I doubt I'll ever get to.

When I said that, it was a not-so-subtle dig at those who argue that if we should return to the Moon, we'll get "bogged down" there, and never go to Mars and all, therefore, Mars should be the first and only priority of human spaceflight.  The fact is, we're bogged down on Earth now, and that is not likely to change for political reasons alone.
Sometimes I just flat out don't get it.

Offline UncleMatt

  • Member
  • Posts: 15
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #93 on: 09/02/2011 10:15 PM »
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...

http://en.wikipedia.org/wiki/Magnetosphere
And this is take directly from your "source":

"Mars, with little or no magnetic field is thought to have lost much of its former oceans and atmosphere to space in part due to the direct impact of the solar wind."

With no magnetic field, the atmosphere simply degrades away into space as the solar wind sweeps by. So no matter how thick you could reasonably make the Mars atmosphere, it would never allow for the long term viability of life on the surface. No planetary magnetic field means no unshielded habitation on the surface is practical on Mars.

Offline UncleMatt

  • Member
  • Posts: 15
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #94 on: 09/02/2011 10:19 PM »
Planetary surfaces like Mars, definitely. You have a huge amount of resources available (tons and tons of free metal just within walking distance of any spot), you have an atmosphere that takes care of radiation shielding for you plus easy ISRU anywhere on the planet, you have frozen water, you have regolith that is rounded by aeolian processes instead of resembling broken glass (and thus can serve as a good growing medium, etc), the atmospheric pressure can be increased to high enough to not require pressure suits by increasing the surface temperature slightly through sprinkling carbon black powder strategically over the surface (the higher pressure also allowing liquid water and maybe even plants to grow on the surface, possibly), etc.

All at rest with respect to you, as opposed to moving in different directions at different delta-vs.
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.
That's just plain false. A thick enough atmosphere works just fine for radiation shielding.
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...
It's such an obvious point that finding a direct source that says it explicitly may be difficult. But here's an article on wikipedia: "In passing through matter, fast charged particles ionize the atoms or molecules which they encounter. Thus, the fast particles gradually lose energy in many small steps" http://en.wikipedia.org/wiki/Stopping_power_(particle_radiation)

Magnetic fields are only effective at shielding charged particles, anyways. A thick atmosphere can attenuate UV and some X-ray radiation, as well.

I should know what I'm talking about; I have a Bachelor's of Science degree in physics and am now taking an upper-level course in Space Physics (dealing with space radiation, interaction with planetary magnetic fields, etc).
Come now, a person of your advanced learning and education should know much better than to make a claim without a source to back it up, right? Thats the basis of much of science as we know it: verifiability of information. And if it is so very elementary, you should be able to quote chapter and verse off the top of your head...

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #95 on: 09/02/2011 10:39 PM »
You apparently don't understand the concept of stopping power. A charged particle has a finite distance that it can travel through air before being stopped because it leaves a trail of ions as it goes through the air (and ionizing the air takes energy... which slows the particle down to a stop after a certain distance).

This is so bloody obvious, and it is in the link I posted before (though the forum software ate it the first time I posted it) http://en.wikipedia.org/wiki/Stopping_power_(particle_radiation)

I've done the experiment myself during my Sophomore year in college. It's easy to see in any cloud chamber (in fact, cloud chambers wouldn't work if charged particles weren't affected by atmosphere):
« Last Edit: 09/02/2011 11:32 PM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Warren Platts

I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...

http://en.wikipedia.org/wiki/Magnetosphere
And this is take directly from your "source":

"Mars, with little or no magnetic field is thought to have lost much of its former oceans and atmosphere to space in part due to the direct impact of the solar wind."

With no magnetic field, the atmosphere simply degrades away into space as the solar wind sweeps by. So no matter how thick you could reasonably make the Mars atmosphere, it would never allow for the long term viability of life on the surface. No planetary magnetic field means no unshielded habitation on the surface is practical on Mars.

"Long-term" is relative. A million years is a blink on the geological time-scale, but it's plenty long-term for a human time scale.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Rhyshaelkan

  • Full Member
  • **
  • Posts: 264
    • PERMANENT Forums
  • Liked: 25
  • Likes Given: 37
Re: Which is easier, building industry on planets, or in space?
« Reply #97 on: 09/03/2011 01:06 AM »
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...

http://en.wikipedia.org/wiki/Magnetosphere
And this is take directly from your "source":

"Mars, with little or no magnetic field is thought to have lost much of its former oceans and atmosphere to space in part due to the direct impact of the solar wind."

With no magnetic field, the atmosphere simply degrades away into space as the solar wind sweeps by. So no matter how thick you could reasonably make the Mars atmosphere, it would never allow for the long term viability of life on the surface. No planetary magnetic field means no unshielded habitation on the surface is practical on Mars.

"Long-term" is relative. A million years is a blink on the geological time-scale, but it's plenty long-term for a human time scale.

Indeed. Someone with more brain wattage than I calculated that if you could raise Mars to 1 ata. It would take millions of years before the solar wind would strip it away to a non-life sustaining level. If you were somehow to raise the Earth's moon to 1 ata it would take thousands of years before the Moon would no longer have a breathable atmosphere.

As human recorded history is only 10000-6000 years(depending on who you question). Our entire civilization could grow thrive and die before a 1 ata Mars would become uninhabitable, by the process of solar wind degradation of the atmosphere. Other ways to make Mars uninhabitable might do the job better :D
I am not a professional. Just a rational amateur dreaming of mankind exploiting the universe.

Offline UncleMatt

  • Member
  • Posts: 15
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #98 on: 09/04/2011 11:21 AM »
If you can't post a source other than wikipedia, we don't have anything further to discuss...

Offline UncleMatt

  • Member
  • Posts: 15
  • Liked: 0
  • Likes Given: 0
Re: Which is easier, building industry on planets, or in space?
« Reply #99 on: 09/04/2011 11:22 AM »
I believe you are mistaken, but if you have a verifiable source, I would be happy to read it...

http://en.wikipedia.org/wiki/Magnetosphere
And this is take directly from your "source":

"Mars, with little or no magnetic field is thought to have lost much of its former oceans and atmosphere to space in part due to the direct impact of the solar wind."

With no magnetic field, the atmosphere simply degrades away into space as the solar wind sweeps by. So no matter how thick you could reasonably make the Mars atmosphere, it would never allow for the long term viability of life on the surface. No planetary magnetic field means no unshielded habitation on the surface is practical on Mars.

"Long-term" is relative. A million years is a blink on the geological time-scale, but it's plenty long-term for a human time scale.

Indeed. Someone with more brain wattage than I calculated that if you could raise Mars to 1 ata. It would take millions of years before the solar wind would strip it away to a non-life sustaining level. If you were somehow to raise the Earth's moon to 1 ata it would take thousands of years before the Moon would no longer have a breathable atmosphere.

As human recorded history is only 10000-6000 years(depending on who you question). Our entire civilization could grow thrive and die before a 1 ata Mars would become uninhabitable, by the process of solar wind degradation of the atmosphere. Other ways to make Mars uninhabitable might do the job better :D
Save your insults for someone else, I just want to see your sources of information that are suporting your claims. Thats all, nothing else.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 32243
  • Cape Canaveral Spaceport
  • Liked: 10898
  • Likes Given: 325
Re: Which is easier, building industry on planets, or in space?
« Reply #100 on: 09/04/2011 01:37 PM »
Uh, no, since Mars has no magnetic field to deflect high energy particles and radiation from the sun, it won't matter how thick you make the atmosphere on Mars. Mars is constantly losing its atmosphere to solar wind as well. You can make the atmosphere as thick as you want on Mars, and it still won't protect unshielded organisms from radiation/high energy particles.

Your source please

Online A_M_Swallow

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8396
  • South coast of England
  • Liked: 313
  • Likes Given: 135
Re: Which is easier, building industry on planets, or in space?
« Reply #101 on: 09/04/2011 01:38 PM »
If you can't post a source other than wikipedia, we don't have anything further to discuss...

True.  He won.

Offline Hop_David

  • Full Member
  • ****
  • Posts: 1636
  • Ajo, Arizona
    • Hop's Gallery
  • Liked: 115
  • Likes Given: 42
Re: Which is easier, building industry on planets, or in space?
« Reply #102 on: 09/04/2011 10:41 PM »
If you can't post a source other than wikipedia, we don't have anything further to discuss...

The Wikipedia Stopping Power article Robotbeat pointed to cites these sources:


^ ICRU Report 73: Stopping of Ions heavier than Helium, Journal of the ICRU, 5 No. 1 (2005), Oxford Univ. Press ISBN 0198570120
^ P. Sigmund: Stopping of heavy ions. Springer Tracts in Modern Physics Vol. 204 (2004) ISBN 3540222731
^ Stopping Power for Light Ions
^ Paul, H (2006). "A comparison of recent stopping power tables for light and medium-heavy ions with experimental data, and applications to radiotherapy dosimetry". Nuclear Instruments and Methods in Physics Research Section B 247: 166. Bibcode 2006NIMPB.247..166P. doi:10.1016/j.nimb.2006.01.059.
^ a b ICRU Report 60: Fundamental Quantities and Units for Ionizing Radiation. International Commission on Radiation Units and Measurements, Bethesda, MD, USA (1998) ISBN 0913394599
^ a b c d J. F. Ziegler, J. P. Biersack, and U. Littmark. In The Stopping and Range of Ions in Matter, volume 1, New York, 1985. Pergamon. ISBN 0080220533
^ a b SRIM web site
^ W. E. Burcham. Elements of nuclear physics. Longman, London and New York, 1979 ISBN 0582460271
^ Nordlund, K; Runeberg, N; Sundholm, D (1997). "Repulsive interatomic potentials calculated using Hartree-Fock and density-functional theory methods". Nuclear Instruments and Methods in Physics Research Section B 132: 45. Bibcode 1997NIMPB.132...45N. doi:10.1016/S0168-583X(97)00447-3.
^ Robinson, Mark; Torrens, Ian (1974). "Computer simulation of atomic-displacement cascades in solids in the binary-collision approximation". Physical Review B 9: 5008. Bibcode 1974PhRvB...9.5008R. doi:10.1103/PhysRevB.9.5008.
^ Biersack, J; Haggmark, L (1980). "A Monte Carlo computer program for the transport of energetic ions in amorphous targets☆". Nuclear Instruments and Methods 174: 257. Bibcode 1980NucIM.174..257B. doi:10.1016/0029-554X(80)90440-1.
^ Robinson, M (1992). "Computer simulation studies of high-energy collision cascades1". Nuclear Instruments and Methods in Physics Research Section B 67: 396. Bibcode 1992NIMPB..67..396R. doi:10.1016/0168-583X(92)95839-J.
^ Nordlund, K (1995). "Molecular dynamics simulation of ion ranges in the 1–100 keV energy range". Computational Materials Science 3: 448. doi:10.1016/0927-0256(94)00085-Q.
^ Beardmore, Keith; Grønbech-Jensen, Niels (1998). "Efficient molecular dynamics scheme for the calculation of dopant profiles due to ion implantation". Physical Review E 57: 7278. arXiv:physics/9901054. Bibcode 1998PhRvE..57.7278B. doi:10.1103/PhysRevE.57.7278.

At the moment, I judge Robotbeat's argument persuasive.

Unless I've missed something, you've cited zero sources to support your notion that a magnetosphere is necessary for radiation protection.

Offline Tass

  • Full Member
  • ***
  • Posts: 361
  • Liked: 76
  • Likes Given: 153
Re: Which is easier, building industry on planets, or in space?
« Reply #103 on: 09/06/2011 08:19 AM »
Indeed. Someone with more brain wattage than I calculated that if you could raise Mars to 1 ata. It would take millions of years before the solar wind would strip it away to a non-life sustaining level. If you were somehow to raise the Earth's moon to 1 ata it would take thousands of years before the Moon would no longer have a breathable atmosphere.

As human recorded history is only 10000-6000 years(depending on who you question). Our entire civilization could grow thrive and die before a 1 ata Mars would become uninhabitable, by the process of solar wind degradation of the atmosphere. Other ways to make Mars uninhabitable might do the job better :D
Save your insults for someone else, I just want to see your sources of information that are suporting your claims. Thats all, nothing else.
I may be blind or something, but I am utterly incapable of finding even a single insult in the above post. 

Offline Rhyshaelkan

  • Full Member
  • **
  • Posts: 264
    • PERMANENT Forums
  • Liked: 25
  • Likes Given: 37
Re: Which is easier, building industry on planets, or in space?
« Reply #104 on: 09/06/2011 08:51 AM »
Indeed. Someone with more brain wattage than I calculated that if you could raise Mars to 1 ata. It would take millions of years before the solar wind would strip it away to a non-life sustaining level. If you were somehow to raise the Earth's moon to 1 ata it would take thousands of years before the Moon would no longer have a breathable atmosphere.

As human recorded history is only 10000-6000 years(depending on who you question). Our entire civilization could grow thrive and die before a 1 ata Mars would become uninhabitable, by the process of solar wind degradation of the atmosphere. Other ways to make Mars uninhabitable might do the job better :D
Save your insults for someone else, I just want to see your sources of information that are suporting your claims. Thats all, nothing else.
I may be blind or something, but I am utterly incapable of finding even a single insult in the above post. 

I am sure the insult was misconstrued when I said "degradation." Some people cannot take a joke.
I am not a professional. Just a rational amateur dreaming of mankind exploiting the universe.

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #105 on: 09/06/2011 12:40 PM »
I may be blind or something, but I am utterly incapable of finding even a single insult in the above post. 

What?  Are you saying that blind people are the  problem with HSF? 

There.  That quick example of the faulty reasoning which characterizes some posters.  Such faulty reasoning is ensconced in the higher levels of our politics, bureacracies, and so forth.  And it plays out in many ways.  For example, "Mars is easier".  "Frankly, we've been to the Moon before".  "Four segments can't be made to work.  Only five segments."

The post in question was not insulting in the least.  In some ways, the sequence was childish.  "Show me your source".  "Oh yeah? Show me your source!"  The thinking being that an opinion or observation is a priori false without a link, no matter how spurious the link.  The lack of admitting contrary evidence, no matter what.  The insistance upon only accepting evidence that supports a claim.

Boring, but oh well.
Sometimes I just flat out don't get it.

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #106 on: 09/06/2011 09:42 PM »
If you can't post a source other than wikipedia, we don't have anything further to discuss...
As noted by others, the wikipedia article in question had a page of sources cited.

Even better, I showed you a video of the phenomenon in question (high energy charged particles interacting and losing energy to and having a limited range in the atmosphere--i.e. being stopped by air). The experiment is easily repeatable with household items and items available at a grocery store or drug store (smoke detector, black construction paper, felt, dry ice, rubbing alcohol, that sort of thing). Here's another example, using only household-type items:

What more do you want?
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #107 on: 09/06/2011 10:07 PM »
You apparently don't understand the concept of stopping power. A charged particle has a finite distance that it can travel through air before being stopped because it leaves a trail of ions as it goes through the air (and ionizing the air takes energy... which slows the particle down to a stop after a certain distance).

This is so bloody obvious, and it is in the link I posted before (though the forum software ate it the first time I posted it) http://en.wikipedia.org/wiki/Stopping_power_(particle_radiation)

I've done the experiment myself during my Sophomore year in college. It's easy to see in any cloud chamber (in fact, cloud chambers wouldn't work if charged particles weren't affected by atmosphere):


All these by-products and ionized air particles created by the high energy particle's interaction with atmosphere that can do more damage to a human than if there had been no atmosphere in the first place.  However, if the original particle was charged then a magnetic field could stop it before interaction with the atmosphere.

I don't think you are saying this, but claiming that having a thick enough atmosphere is the only factor to consider in creating a safe radiation environment on Mars is wrong.  Magnetic field has to be considered as well.

Our radiation safe conditions on Earth are a result of both thick atmosphere and a magnetic field.  One without the other may not cut it on Mars, especially the likely situation of a thin (compared to earth) atmosphere and no magnetic field.
« Last Edit: 09/06/2011 10:10 PM by LegendCJS »
Remember: if we want this whole space thing to work out we have to optimize for cost!

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #108 on: 09/06/2011 10:17 PM »
Except you are wrong. If Mars had a thick, Earth-like atmosphere, the radiation dosage would be lower than the background radiation of some areas on Earth. An Earth-like magnetic field doesn't help deflect the highest energy cosmic rays, anyway, though it does help lower the radiation dosage somewhat in LEO. But the atmosphere is more important (since it shields against UV and X-rays, as well... something that magnetic fields have exactly zero influence on), and if thick enough can provide plenty of shielding for Mars inhabitants. A magnetic field is helpful, but is most certainly not absolutely required for effective shielding.

A thick enough atmosphere is good enough for completely safe levels of shielding even with ZERO magnetic field.

Heck, the cosmic ray radiation dosage in Hellas Basin, with just the current atmosphere of Mars, is already as low as the background radiation in parts of Ramsar, Iran (10 rem is basically equivalent to 100 mSv):
http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA03480
Quote
The areas of Mars expected to have the lowest levels of cosmic radiation are where the elevation is lowest, because those areas have more atmosphere above them to block out some of the radiation. Earth's thick atmosphere shields us from most cosmic radiation, but Mars has a much thinner atmosphere than we have on Earth.

For reference, the natural background dose in parts of Ramsar, Iran, is about 132 mSv (~13rem/year) inside some residences, and people live and have lived long, healthy lives there for generations. http://www.angelfire.com/mo/radioadaptive/ramsar.html
« Last Edit: 09/06/2011 10:24 PM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline LegendCJS

  • Full Member
  • ****
  • Posts: 575
  • Boston, MA
  • Liked: 7
  • Likes Given: 2
Re: Which is easier, building industry on planets, or in space?
« Reply #109 on: 09/07/2011 12:22 AM »
Except you are wrong. If Mars had a thick, Earth-like atmosphere, the radiation dosage would be lower than the background radiation of some areas on Earth. An Earth-like magnetic field doesn't help deflect the highest energy cosmic rays, anyway, though it does help lower the radiation dosage somewhat in LEO. But the atmosphere is more important (since it shields against UV and X-rays, as well... something that magnetic fields have exactly zero influence on), and if thick enough can provide plenty of shielding for Mars inhabitants. A magnetic field is helpful, but is most certainly not absolutely required for effective shielding.

A thick enough atmosphere is good enough for completely safe levels of shielding even with ZERO magnetic field.

Heck, the cosmic ray radiation dosage in Hellas Basin, with just the current atmosphere of Mars, is already as low as the background radiation in parts of Ramsar, Iran (10 rem is basically equivalent to 100 mSv):
http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA03480
Quote
The areas of Mars expected to have the lowest levels of cosmic radiation are where the elevation is lowest, because those areas have more atmosphere above them to block out some of the radiation. Earth's thick atmosphere shields us from most cosmic radiation, but Mars has a much thinner atmosphere than we have on Earth.

For reference, the natural background dose in parts of Ramsar, Iran, is about 132 mSv (~13rem/year) inside some residences, and people live and have lived long, healthy lives there for generations. http://www.angelfire.com/mo/radioadaptive/ramsar.html

About atmospheric shielding of UV: I present to you this reference: http://www.sciencedaily.com/releases/2001/08/010802080620.htm.

It states that solar wind generated charged particles destroy ozone through the mechanism of breaking nitrogen and water molecules apart and forming hydrogen and nitrogen oxides, which in turn destroy ozone.  Hydrogen oxides last for the duration of the solar storm event, while the nitrogen oxides last for months afterwards.  It was stated that for a particular event studied on order of 1% of atmospheric ozone was destroyed due to a solar flare/ coronal mass ejection that punched its way through Earth's magnetic field.

One percent per large solar storm event is not that much, but with no magnetic field on Mars, the assault would be continuous. Both kinds of oxides would be present in perpetuity, with nitrogen oxide building to significant levels.

It would stand to reason that with no magnetic field a planetary atmosphere could not maintain ozone levels in significant quantities to block UV radiation.

I buy the greater importance of atmospheric mass over magnetic field in blocking other kinds of radiation.

I suppose the discussion of having any ozone at all in a terraformed atmosphere is kind of an oxymoron given that most strategies for terra-forming Mars involve releasing large amounts of high GWP gasses like CFCs and the like, especially ones with lifetimes of O(10^4) years in the atmosphere.
« Last Edit: 09/07/2011 12:31 AM by LegendCJS »
Remember: if we want this whole space thing to work out we have to optimize for cost!

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #110 on: 09/07/2011 12:39 AM »
Right, a magnetic field is important for shielding the atmosphere from being stripped away (and other effects like you linked to) on a long timeline.

It's not unreasonable to imagine that if you had managed to terraform Mars, you could much more easily build a large superconducting ring around the Martian equator to create a magnetic dipole as great as the Earth's magnetic field (something like 9*10^22 Amps*m^2). The superconductor current density record is something like 27 MA/cm^2, so a cable around Mars's equator carrying enough current to create a dipole as great as the Earth's would have a cross section of 100 cm^2, or would be about five inches in diameter (plus cooling and insulation). That's really not that big. And we're likely to make significant advances in superconductors (as far as current density goes, at least) in the next million or so years! ;)
« Last Edit: 09/07/2011 12:40 AM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 9161
  • Delta-t is the salient metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 617
  • Likes Given: 320
Re: Which is easier, building industry on planets, or in space?
« Reply #111 on: 09/07/2011 05:15 PM »
The experiment is easily repeatable with household items ...

Didn't they give an actual demonstration of this technique in the documentary film "ET"?
Sometimes I just flat out don't get it.

Offline Rhyshaelkan

  • Full Member
  • **
  • Posts: 264
    • PERMANENT Forums
  • Liked: 25
  • Likes Given: 37
I am not a professional. Just a rational amateur dreaming of mankind exploiting the universe.


Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28128
  • Minnesota
  • Liked: 7926
  • Likes Given: 5280
Re: Which is easier, building industry on planets, or in space?
« Reply #114 on: 09/30/2011 11:58 PM »
http://science.nasa.gov/science-news/science-at-nasa/2008/21nov_plasmoids/


Over a timescale of hundreds of millions of years. Far longer than we've even been a species. Heck, longer than there's been mammals on Earth. While that's an interesting link (and thanks for posting it, it actually is pretty related to a class I'm taking right now), it doesn't have much to do with the topic at hand. Well, at least not much more than the fact that the Sun is going to enter its Red Giant phase, eventually. It's not impossible to produce an artificial field strong enough to keep the atmosphere from leaving over millions of years.
« Last Edit: 10/01/2011 12:01 AM by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Tags: