NASA proposes artificial magnetic field to make Mars a second home

[Yousuf Khan]

http://www.zdnet.com/article/nasa-proposes-artificial-magnetic-field-to-make-mars-a-second-home/

> However, researchers have proposed a way to make Mars more habitable -- by creating an artificial magnetic field to reduce radiation levels.
>
> To combat some of the main barriers to sending humans to Mars, as reported by Universe Today, last week, NASA hosted a discussion and presentation group called the Planetary Science Vision 2050 Workshop.
>
> At the event, scientists and researchers discussed the future possibilities of space exploration, and during one talk, NASA Planetary Science Division Director Dr. Jim Green proposed ways to deploy a magnetic shield around the planet which could act as a barrier to radiation and reduce the need for extreme protective equipment.
>
> The proposal (.PDF) relies on the theory that over four billion years ago, the planet's magnetic field vanished, turning the planet from a warm, wet environment to a dry husk. Without returning some kind of magnetic field to Mars, this situation will not change.
>
> Green proposes that by placing a magnetic dipole shield at the Mars L1 Lagrange Point, a man-made magnetosphere sphere would cradle the entire planet.
>
> The team says that previous tests in lab conditions suggest that inflatable structures could potentially generate a magnetic dipole field at a level of perhaps 1 or 2 Tesla, protecting against both radiation and solar winds.
>
> In addition, such a field could result in Mars' atmosphere thickening over time, creating a greenhouse effect which could increase the planet's surface temperature by up to four degrees and melt northern polar ice caps.
>
> While Green admits the idea is somewhat "fanciful," the scientists insist that it is not outside the realm of possibility, and could assist in the future exploration of the planet.

[S Ergio]

On 3/8/2017 6:42 AM, Yousuf Khan wrote:
> http://www.zdnet.com/article/nasa-proposes-artificial-magnetic-field-to-make-mars-a-second-home/
>
>
>> However, researchers have proposed a way to make Mars more habitable
>> -- by creating an artificial magnetic field to reduce radiation levels.
>>
>> To combat some of the main barriers to sending humans to Mars, as
>> reported by Universe Today, last week, NASA hosted a discussion and
>> presentation group called the Planetary Science Vision 2050 Workshop.

>> At the event, scientists and researchers discussed the future
>> possibilities of space exploration, and during one talk, NASA
>> Planetary Science Division Director Dr. Jim Green proposed ways to
>> deploy a magnetic shield around the planet which could act as a
>> barrier to radiation and reduce the need for extreme protective
>> equipment.
>>
>> The proposal (.PDF) relies on the theory that over four billion years
>> ago, the planet's magnetic field vanished, turning the planet from a
>> warm, wet environment to a dry husk. Without returning some kind of
>> magnetic field to Mars, this situation will not change.
>>
>> Green proposes that by placing a magnetic dipole shield at the Mars L1
>> Lagrange Point, a man-made magnetosphere sphere would cradle the
>> entire planet.

how far away is Mars L1 Lagrange Point from Mars ?

about 141,000,000 miles.

how does magnetic field strength decline with distance ?

1/d^2 ?

so you need a magnet of at least 2*10^16 telsa ? ?


why not just put it on the surface ? by the way, you will have to water
cool it too.

extra credit questions;

1. how much water is needed to cool magnet that generates a 1 T field
100,000 miles away. (how is this water stored?)

2. how much electricity in megawatts is required to run magnet, then to
pump water.

3. what % of partials will be deflected away and outside a 100 mile zone
on the surface around the magnet? (assume 98% speed of light)

4. What type of partials will be hardly by magnet ?

>>
>> While Green admits the idea is somewhat "fanciful,"

this dude works at NASA ???

[dlzc]

Dear S Ergio:

On Wednesday, March 8, 2017 at 7:16:41 AM UTC-7, S Ergio wrote:
> On 3/8/2017 6:42 AM, Yousuf Khan wrote:
> > http://www.zdnet.com/article/nasa-proposes-artificial-magnetic-field-to-make-mars-a-second-home/

...

> >> While Green admits the idea is somewhat "fanciful,"
>
> this dude works at NASA ???

So did/does the inventor of the Alcubierre drive...

David A. Smith

[Yousuf Khan]

On 3/8/2017 9:16 AM, S Ergio wrote:
> On 3/8/2017 6:42 AM, Yousuf Khan wrote:
>> http://www.zdnet.com/article/nasa-proposes-artificial-magnetic-field-to-make-mars-a-second-home/
>>
>

> how far away is Mars L1 Lagrange Point from Mars ?
>
> about 141,000,000 miles.

You're completely wrong. You can be sure that you're completely wrong
because that distance is greater than the distance between the Earth and
the Sun! The distance you came up with is the distance between the Sun
and Mars.

The L1 point for Mars is actually about 655,000 miles, or about 1
million kilometers.

http://www.wolframalpha.com/input/?i=lagrange+point+Mars+Sun

> how does magnetic field strength decline with distance ?
>
> 1/d^2 ?
>
> so you need a magnet of at least 2*10^16 telsa ? ?

Earth's magnetic field at the surface is only 54 microteslas. The
devices they are talking about are about 1 or 2 teslas, which should be
enough to protect Mars.

http://www.wolframalpha.com/input/?i=strength+of+Earth%27s+magnetic+field

> why not just put it on the surface ? by the way, you will have to water
> cool it too.

On the surface, you'd need multiple devices. In orbit, only need the one.

The power source is likely to be the Sun, through solar panels. Cooling
through radiators into space.

>>> While Green admits the idea is somewhat "fanciful,"
>
> this dude works at NASA ???

Why not? You've certainly shown that you don't know what you're talking
about.

Yousuf Khan

[S Ergio]

for small energy useage.

>
>>>> While Green admits the idea is somewhat "fanciful,"
>>
>> this dude works at NASA ???
>
> Why not? You've certainly shown that you don't know what you're talking
> about.
>
> Yousuf Khan

thanks for the info,

that dude should have provided the numbers to back himself up, back of
the envelope should do.


so how much is the field 655,000 miles away from a one T source ?

how much fuel on board with the sattilite need to compensate for pushing
particals around?

Gamma rays are not deflected and come in at full strength to the ground,
on earth the atmosphere protects us from 95% of them. so how much gamma
can a crew take ? a year or two ?

and again, to cosmic rays, at what angle can they be deflected from
orgional their path, using a magnetic field, is it only 1 or 2 degrees ?

[The Starmaker]

pro·pose
pr?'poz/
verb
3rd person present: proposes

1.
put forward (an idea or plan) for consideration or discussion by
others.



Get wit the program...it's fake news.


They sit in a room everyday with only one agenda...pro·pose.


They are simply tryin to remain...revelant, but they are not.


Read the Headline: "NASA proposes..."

It's just fuckin TALK!


Get wit the program...it's fake news.


You're just a wishful thinker...Yousuf.


The first step, think for yourself..

[Yousuf Khan]

On 3/8/2017 12:51 PM, S Ergio wrote:
> thanks for the info,
>
> that dude should have provided the numbers to back himself up, back of
> the envelope should do.

I'm sure he has, this is just a popular science article which summarizes
his proposal, and gives you an idea about what some scientists have come
up with. It's up to you to go see his original proposal paper, if you
want more details.

> so how much is the field 655,000 miles away from a one T source ?

Actually the magnetic field strength drops away by a factor of inverse
cubed not inverse squared. But it really doesn't matter how strong the
magnetic field is at the surface of Mars, just so long as it's ahead of
Mars and it produces a large enough bow shock pattern, similar to how
the bow shock pattern is produced ahead of Earth, diverting the solar
wind away from Earth.

> how much fuel on board with the sattilite need to compensate for pushing
> particals around?

Don't know, perhaps they'll find a clever way to use the magnetic field
itself as a propulsion tool to keep it stable in the L1?

> Gamma rays are not deflected and come in at full strength to the ground,
> on earth the atmosphere protects us from 95% of them. so how much gamma
> can a crew take ? a year or two ?

The magnetic field doesn't protect against any kind of EM radiation, no
matter what. All it protects against is the solar winds. This in turn
creates a shield of the upper atmosphere to protect against the high
energy photons from penetrating into the lower atmosphere.

Fortunately, gamma rays are usually an uncommon type of photons in the
universe, as most of the gamma rays occur inside the cores of stars
during nuclear fusion, and they all get diffused into lower energy
photons by the time they exit the star's photosphere. Most sources of
raw gamma rays are things such as supernovas and quasars, and those are
very directional in their nature. Another advantage is that these
sources of gamma rays are also pretty distant.

> and again, to cosmic rays, at what angle can they be deflected from
> orgional their path, using a magnetic field, is it only 1 or 2 degrees ?

Earth's magnetic field doesn't stop cosmic rays either, they tend to hit
the Earth relatively unopposed. Again fortunately due to the fact that
cosmic rays are high energy particles produced by supernovas and active
galactic nuclei, they are relatively rare. Most of the cosmic rays are
diverted by the Sun's magnetic field rather than any single planet's
(though Jupiter's might be strong enough to divert some too).

Most cosmic rays are travelling at relativistic speeds, so no puny
magnetic field short of a magnetar is going to do much to divert any
cosmic rays. We used to use cosmic ray showers in the atmosphere to
detect new particles, prior to the advent of supercolliders.

[The Starmaker]

"This may sound “fanciful” but new research is starting
to emerge revealing that a miniature magnetsphere can
be used to protect humans
and spacecraft."



He could at least learn how to spel....magnetsphere.
http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf



fan·ci·ful
'fans?f?l/
adjective
adjective: fanciful

(of a person or their thoughts and ideas) overimaginative and unrealistic.



At least he's honest about his thinking...unrealstic.



Put him in charge of ...NASA.

[S Ergio]

On 3/8/2017 9:44 PM, Yousuf Khan wrote:
> On 3/8/2017 12:51 PM, S Ergio wrote:
>> thanks for the info,
>>
>> that dude should have provided the numbers to back himself up, back of
>> the envelope should do.
>
> I'm sure he has, this is just a popular science article which summarizes
> his proposal, and gives you an idea about what some scientists have come
> up with. It's up to you to go see his original proposal paper, if you
> want more details.
>
>> so how much is the field 655,000 miles away from a one T source ?
>
> Actually the magnetic field strength drops away by a factor of inverse
> cubed not inverse squared.

so it is far weaker than d^(-2),
for a rough order of magnitude, compair 1 mile out vs 655,000 miles out
1/(655000)^3 = 3.56 * 10^(-18)

so if the source could generate a 1 T field a mile away, then 655,000
miles away the field is 3.56 E-18, so the generator has no field on Mars.

> But it really doesn't matter how strong the
> magnetic field is at the surface of Mars, just so long as it's ahead of
> Mars and it produces a large enough bow shock pattern, similar to how
> the bow shock pattern is produced ahead of Earth, diverting the solar
> wind away from Earth.

but the L1 is not in the path of Sun to Mars, where particles go. It is
at L1 way out of the way, 60 degrees off.
diagram here;
http://www.spaceacademy.net.au/library/notes/lagrangp.htm

>
>> how much fuel on board with the sattilite need to compensate for pushing
>> particals around?
>
> Don't know, perhaps they'll find a clever way to use the magnetic field
> itself as a propulsion tool to keep it stable in the L1?

nothing to push aginst. one has to eject mass.

>
>> Gamma rays are not deflected and come in at full strength to the ground,
>> on earth the atmosphere protects us from 95% of them. so how much gamma
>> can a crew take ? a year or two ?
>
> The magnetic field doesn't protect against any kind of EM radiation, no
> matter what. All it protects against is the solar winds. This in turn
> creates a shield of the upper atmosphere to protect against the high
> energy photons from penetrating into the lower atmosphere.

No such shield on Mars, need a lot of atmosphere, on earth yes, [that is
why we are able to live on the surface of earth, atmosphere blocks most
gammas]

>
> Fortunately, gamma rays are usually an uncommon type of photons in the
> universe, as most of the gamma rays occur inside the cores of stars
> during nuclear fusion, and they all get diffused into lower energy
> photons by the time they exit the star's photosphere. Most sources of
> raw gamma rays are things such as supernovas and quasars, and those are
> very directional in their nature. Another advantage is that these
> sources of gamma rays are also pretty distant.

the sun emits gamma, and being distant does not make them weaker,

I havent found gamma ray radiation levels in space yet, there is a lot
of data NASA has already but they make it very hard to find;

"Measuring Space Radiation Between the Earth
and Mars
As the Mars Odyssey spacecraft made its way to Mars between
April and October 2001, the Mars radiation environment
experiment (MARIE) measured the amounts and kinds of space
radiation the spacecraft encountered along the way. These data
are essential to understanding how much and what kinds of
radiation future space travelers might encounter on a long trip
to explore the red planet.
Now in orbit around Mars, MARIE continues to measure the
amount of harmful radiation at the planet itself. Unlike Earth,
Mars does not have a global magnetic field to shield it from
solar flares and cosmic rays. Mars’ atmosphere is also less
than one percent as thick as the Earth’s. These two factors
make Mars very vulnerable to space radiation.
Aboard the International Space Station and in our own solar
system, NASA researchers continue to quantify the amounts
of space radiation our explorers face every day and will face
in the future. Understanding space radiation will not only protect
the crew currently aboard the International Space Station, but
those first humans who will continue the exploration of our
solar system."

>
>> and again, to cosmic rays, at what angle can they be deflected from
>> orgional their path, using a magnetic field, is it only 1 or 2 degrees ?
>
> Earth's magnetic field doesn't stop cosmic rays either, they tend to hit
> the Earth relatively unopposed.

they get changed, typically they smash into the atmosphere and cause
partical showers, into thousands of less energetic particals, and hit
the surface as a disk shape a few hundred meters across and about 1 or 2
meters thick.

> Again fortunately due to the fact that
> cosmic rays are high energy particles produced by supernovas and active
> galactic nuclei, they are relatively rare.

sun makes a lot of them for local use, sun spots etc

> Most of the cosmic rays are
> diverted by the Sun's magnetic field rather than any single planet's
> (though Jupiter's might be strong enough to divert some too).

"diverted" only means the ray's path was changed, not that the partical
went away.
and the ray travels so fast a local magnetic field has little time to
affect change

>
> Most cosmic rays are travelling at relativistic speeds, so no puny
> magnetic field short of a magnetar is going to do much to divert any
> cosmic rays. We used to use cosmic ray showers in the atmosphere to
> detect new particles, prior to the advent of supercolliders.

yep. with a PMT, some plastic, and Oscope you can detect them coming
in. (all bought off ebay)

so there are some questionable points that NASA guy's idea still has.
I think he moved it from the surface, because the path would not be long
enough to effect change, and moving to L1 is good for stability of
orbit, but not for diverting particals in path from sun, then the loss
infield strength...

[Rodney Pont]

On Thu, 9 Mar 2017 08:47:55 -0600, S Ergio wrote:

>but the L1 is not in the path of Sun to Mars, where particles go. It is
>at L1 way out of the way, 60 degrees off.
>diagram here;
>http://www.spaceacademy.net.au/library/notes/lagrangp.htm

According to Wikipedia L1 is between Mars and the Sun;
https://en.wikipedia.org/wiki/List_of_objects_at_Lagrangian_points

and I thought L1 was always the one between the two bodies.

--
Faster, cheaper, quieter than HS2
and built in 5 years;
UKUltraspeed <http://www.500kmh.com/>

[S Ergio]

On 3/9/2017 10:21 AM, Rodney Pont wrote:
> On Thu, 9 Mar 2017 08:47:55 -0600, S Ergio wrote:
>
>> but the L1 is not in the path of Sun to Mars, where particles go. It is
>> at L1 way out of the way, 60 degrees off.
>> diagram here;
>> http://www.spaceacademy.net.au/library/notes/lagrangp.htm
>
> According to Wikipedia L1 is between Mars and the Sun;
> https://en.wikipedia.org/wiki/List_of_objects_at_Lagrangian_points
>
> and I thought L1 was always the one between the two bodies.
>

you are right, guess I was thinking L4 or L5,

[I make mistake, first of the year, that I know of...]


L1 would be effective

mars is 92,900,000 miles from the sun and L1 was stated as 655,000 miles
out, or 0.7% of the way.

if you double the effective radius from L1, the magnetic field, the
partical would be exposed to the mag field for about 7 seconds from the sun.

I think the magnetic field drops off as d^(-3) nearby L1, but is d^(-2)
after a ways out.

the other problem is a magnetic field generator at L1, will alter paths
of sun generated cosmic rays, charged particals, but will they be
deflected away from Mars, or focus them on mars, or have little effect.
think of orentation of the field to incoming particals, seems like it
would need to be like earths, NS out of the galactic plane



some information here too
https://www-spof.gsfc.nasa.gov/Education/FAQs6.html

[The Starmaker]

john wrote:
>
> Just build the Space Elevator right
> out to Mars and plug in.

That sounds like a great...proposes!


but don't you want to dig a hole first?

i proposes
to dig a hole
through the earth
to make an elevator
to China, then
keeping building
to Mars.

would i end up upside down in China? or are they upside down??

how do i get to Mars right side up???

[Rodney Pont]

On Thu, 9 Mar 2017 10:50:41 -0600, S Ergio wrote:

>mars is 92,900,000 miles from the sun and L1 was stated as 655,000 miles
>out, or 0.7% of the way.

You're over 50 million miles short with that figure, that's about the
93 million miles Earth is from the sun. Are you getting these from
memory or a dubious source?

[S Ergio]

On 3/9/2017 1:04 PM, Rodney Pont wrote:
> On Thu, 9 Mar 2017 10:50:41 -0600, S Ergio wrote:
>
>> mars is 92,900,000 miles from the sun and L1 was stated as 655,000 miles
>> out, or 0.7% of the way.
>
> You're over 50 million miles short with that figure, that's about the
> 93 million miles Earth is from the sun. Are you getting these from
> memory or a dubious source?
>

picked it from some website, and they are wrong,

is that my second mistake for this year ? Oh no!

[Yousuf Khan]

That diagram appears to be wrong, it has the L1 and L2 reversed. Other
sources show the L1 is directly between the planet and the Sun.

http://www.space.com/30302-lagrange-points.html

>>> how much fuel on board with the sattilite need to compensate for pushing
>>> particals around?
>>
>> Don't know, perhaps they'll find a clever way to use the magnetic field
>> itself as a propulsion tool to keep it stable in the L1?
>
> nothing to push aginst. one has to eject mass.

Push against the solar wind. If Earth sailors found clever sail designs
to sail against the atmospheric wind hundreds of years ago, I'm sure the
same principles can work against the solar wind.

And who knows, maybe NASA will have completely proven that the EMDRIVE
works by then too, and then there's another way to keep stuff in orbit
properly. We are talking in the distant future for all of this stuff,
after all. :-)

>>> Gamma rays are not deflected and come in at full strength to the ground,
>>> on earth the atmosphere protects us from 95% of them. so how much gamma
>>> can a crew take ? a year or two ?
>>
>> The magnetic field doesn't protect against any kind of EM radiation, no
>> matter what. All it protects against is the solar winds. This in turn
>> creates a shield of the upper atmosphere to protect against the high
>> energy photons from penetrating into the lower atmosphere.
>
> No such shield on Mars, need a lot of atmosphere, on earth yes, [that is
> why we are able to live on the surface of earth, atmosphere blocks most
> gammas]

Exactly, the Martian atmosphere is so depleted that we couldn't even get
it to protect us against high-energy photons. So somehow, if we're going
to terraform Mars, we are going to have put the magnetic shield up to
give the atmosphere a fighting chance to thicken up, and then we have to
thicken it up. If we thicken it, without a magnetic shield, it's just
going to thin out again.

>> Fortunately, gamma rays are usually an uncommon type of photons in the
>> universe, as most of the gamma rays occur inside the cores of stars
>> during nuclear fusion, and they all get diffused into lower energy
>> photons by the time they exit the star's photosphere. Most sources of
>> raw gamma rays are things such as supernovas and quasars, and those are
>> very directional in their nature. Another advantage is that these
>> sources of gamma rays are also pretty distant.
>
> the sun emits gamma, and being distant does not make them weaker,

The Sun emits a small amount of gamma, it mainly emits in the visible
part of the spectrum, especially in the green part of it. Thus we've
evolved to see in the optical ranges. If we grew up on a red dwarf, we'd
evolve to see in the infrared and red part of the spectrum.

By and large, the gamma radiation produced in the core gets bounced
around inside the core and the radiative layers, until it's been reduced
down to at worst UV. 99% of the radiation coming from the Sun is in the
UV, visible, and IR ranges. The remaining 1% is whatever else you have.

http://uv.biospherical.com/student/page3.html

And of course, distance makes radiation weaker, you pointed to it
yourself, its intensity goes down by the square of distance. Gamma Ray
Bursts are aimed directly at the Earth, that's why we see them as GRB's,
otherwise we'd see them only as supernovas. But due to their distance
from us, their gamma rays have little effect on us. If the GRB's were
within a few thousand light-years of us and aimed directly at us, then
we'd be in trouble.

https://www.physicsforums.com/threads/effective-destructive-range-of-supernovae.312925/

>>> and again, to cosmic rays, at what angle can they be deflected from
>>> orgional their path, using a magnetic field, is it only 1 or 2 degrees ?
>>
>> Earth's magnetic field doesn't stop cosmic rays either, they tend to hit
>> the Earth relatively unopposed.
>
> they get changed, typically they smash into the atmosphere and cause
> partical showers, into thousands of less energetic particals, and hit
> the surface as a disk shape a few hundred meters across and about 1 or 2
> meters thick.

They can hit anywhere, it's just that the atmosphere is the first thing
in their path. Some have been known to penetrate to the ground, hence
the reason they try to put neutrino detectors deep underground to avoid
detecting cosmic rays.

>> Again fortunately due to the fact that
>> cosmic rays are high energy particles produced by supernovas and active
>> galactic nuclei, they are relatively rare.
>
> sun makes a lot of them for local use, sun spots etc

Cosmic rays are interstellar, relativistic, and originate out of
blackholes and supernovas. The Sun makes solar winds out of the same
materials (protons and electrons), and they are sub-relativistic.

> so there are some questionable points that NASA guy's idea still has.
> I think he moved it from the surface, because the path would not be long
> enough to effect change, and moving to L1 is good for stability of
> orbit, but not for diverting particals in path from sun, then the loss
> infield strength...

As stated previously, the L1 is the one in the path of the Sun. So it
will divert solar winds away from the planet behind it.

Yousuf Khan

[Rodney Pont]

On Thu, 9 Mar 2017 21:37:48 -0500, Yousuf Khan wrote:

>Push against the solar wind. If Earth sailors found clever sail designs
>to sail against the atmospheric wind hundreds of years ago, I'm sure the
>same principles can work against the solar wind.

Isn't this the ideal application of that magnetic scoop to collect
particles and an ion drive to keep it in position?

[Rodney Pont]

On Thu, 9 Mar 2017 15:31:54 -0600, S Ergio wrote:

>>> mars is 92,900,000 miles from the sun and L1 was stated as 655,000 miles
>>> out, or 0.7% of the way.
>>
>> You're over 50 million miles short with that figure, that's about the
>> 93 million miles Earth is from the sun. Are you getting these from
>> memory or a dubious source?
>>
>
>picked it from some website, and they are wrong,
>
>is that my second mistake for this year ? Oh no!

I'm not keeping a count but two basic errors in the one thread is some
going. Perhaps you could notify your source website(s) :-)

[Yousuf Khan]

On 3/9/2017 4:31 PM, S Ergio wrote:
> picked it from some website, and they are wrong,
>
> is that my second mistake for this year ? Oh no!

That's at least your 3rd mistake, just in this thread alone. Where are
you picking your sources of information from?

Yousuf Khan

[Yousuf Khan]

On 3/10/2017 12:38 AM, Rodney Pont wrote:
> On Thu, 9 Mar 2017 21:37:48 -0500, Yousuf Khan wrote:
>
>> Push against the solar wind. If Earth sailors found clever sail designs
>> to sail against the atmospheric wind hundreds of years ago, I'm sure the
>> same principles can work against the solar wind.
>
> Isn't this the ideal application of that magnetic scoop to collect
> particles and an ion drive to keep it in position?

Even an ion drive will eventually run out of propellant. Then either you
go up to refuel the ion drive, or just make it a disposable spacecraft,
and when one runs out of fuel, you replace it with another one. Wasteful.

[Rodney Pont]

On Fri, 10 Mar 2017 01:51:59 -0500, Yousuf Khan wrote:

>>> Push against the solar wind. If Earth sailors found clever sail designs
>>> to sail against the atmospheric wind hundreds of years ago, I'm sure the
>>> same principles can work against the solar wind.
>>
>> Isn't this the ideal application of that magnetic scoop to collect
>> particles and an ion drive to keep it in position?
>
>Even an ion drive will eventually run out of propellant. Then either you
>go up to refuel the ion drive, or just make it a disposable spacecraft,
>and when one runs out of fuel, you replace it with another one. Wasteful.

That's why I suggested the scoop, to collect more propellant. I'm sure
I've seen a proposed spacecraft with a huge magnetic scoop collecting
particles to fuel the ion drive.

[Yousuf Khan]

On 3/10/2017 2:21 AM, Rodney Pont wrote:
> On Fri, 10 Mar 2017 01:51:59 -0500, Yousuf Khan wrote:
>>> Isn't this the ideal application of that magnetic scoop to collect
>>> particles and an ion drive to keep it in position?
>>
>> Even an ion drive will eventually run out of propellant. Then either you
>> go up to refuel the ion drive, or just make it a disposable spacecraft,
>> and when one runs out of fuel, you replace it with another one. Wasteful.
>
> That's why I suggested the scoop, to collect more propellant. I'm sure
> I've seen a proposed spacecraft with a huge magnetic scoop collecting
> particles to fuel the ion drive.

The propellant ions used are not just any old ions, such as hydrogen
ions, they are usually more massive ions like Xenon. More mass produces
more thrust.

https://en.wikipedia.org/wiki/Ion_thruster

However, I wonder if a large enough magnetic ring can be used like an
ion thruster, only using the solar wind particles, rather than Xenon?
Not only could they use the magnetic field to divert the solar winds
away from the planet, they could also use it as thrust to keep the orbit
stable at the L1 point.

Yousuf Khan

[dlzc]

Dear Yousuf Khan:

On Friday, March 10, 2017 at 6:24:53 AM UTC-7, Yousuf Khan wrote:
...

> However, I wonder if a large enough magnetic
> ring can be used like an ion thruster, only
> using the solar wind particles, rather than
> Xenon?

Where does it get its power from? Won't be solar panels...

> Not only could they use the magnetic field
> to divert the solar winds away from the
> planet, they could also use it as thrust to
> keep the orbit stable at the L1 point.

... which is not where you really want this half-baked system. The particles this "magnetic shield" is to protect you from, are not moving at c. And Mars is still whipping around at a good clip. The "wake" this system produces will fall behind Mars, not *around* Mars. You'd need to "drive" the object a little forward of the stability point.

David A. Smith

[Yousuf Khan]

On 3/10/2017 9:37 AM, dlzc wrote:
> Dear Yousuf Khan:
>
> On Friday, March 10, 2017 at 6:24:53 AM UTC-7, Yousuf Khan wrote:
> ...
>> However, I wonder if a large enough magnetic
>> ring can be used like an ion thruster, only
>> using the solar wind particles, rather than
>> Xenon?
>
> Where does it get its power from? Won't be solar panels...

And why not? Just scale up the number of solar panels to the required
level to get to 1 or 2 Tesla.

>> Not only could they use the magnetic field
>> to divert the solar winds away from the
>> planet, they could also use it as thrust to
>> keep the orbit stable at the L1 point.
>
> ... which is not where you really want this half-baked system. The particles this "magnetic shield" is to protect you from, are not moving at c. And Mars is still whipping around at a good clip. The "wake" this system produces will fall behind Mars, not *around* Mars. You'd need to "drive" the object a little forward of the stability point.

The solar winds aren't travelling at c, they're only going between 300 -
750 km/s.

https://en.wikipedia.org/wiki/Solar_wind

Yousuf Khan

[Dr J R Stockton]

In sci.astro message <o9p3o5$1gve$1...@gioia.aioe.org>, Wed, 8 Mar 2017
08:16:28, S Ergio <inv...@invalid.com> posted:

>On 3/8/2017 6:42 AM, Yousuf Khan wrote:
>> http://www.zdnet.com/article/nasa-proposes-artificial-magnetic-field-
>>to-make-mars-a-second-home/

>>> Green proposes that by placing a magnetic dipole shield at the Mars L1
>>> Lagrange Point, a man-made magnetosphere sphere would cradle the
>>> entire planet.

Sort of. The dipole would shield the dayside of the atmosphere of Mars
from the solar wind. By the way, in the past, at least some respected
authors called L1 "L2" and L2 "L1". The proposal is not by Green; it is
by Green /et al/.

>how far away is Mars L1 Lagrange Point from Mars ?
>about 141,000,000 miles.

Very wrong.

>how does magnetic field strength decline with distance ?
>1/d^2 ?

For that, you need a monopole source. Point-dipole fields go as d^-3.

>so you need a magnet of at least 2*10^16 telsa ? ?

The field strength at the magnet is of itself not important. It is the
dipole moment which creates the far field. Referees should not have
accepted <http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf> as it is,
on those grounds.

>why not just put it on the surface ? by the way, you will have to water
>cool it too.

Because that is a different, and not useful, idea; superconductors were
discovered about 11 decades ago. Use currently-available high-
temperature superconductors or better, and cool by shades as will be
done for JWST; allow the magnet to cool by radiation into the rest of
the Universe.

>extra credit questions;
>
>1. how much water is needed to cool magnet that generates a 1 T field
>100,000 miles away. (how is this water stored?)

None; why 100,000 miles, as according to you L1 is at 141,000,000 miles.
(in a zero-litre container).

>2. how much electricity in megawatts is required to run magnet, then to
>pump water.

None. But energy will be needed to create the dipole moment initially.

>3. what % of partials will be deflected away and outside a 100 mile
>zone on the surface around the magnet? (assume 98% speed of light)

Wrong question.

>4. What type of partials will be hardly by magnet ?

Parse failure. Try writing in your native language.

>>> While Green admits the idea is somewhat "fanciful,"
>
>this dude works at NASA ???

Why not? NASA must have canteen staff, toilet cleaners, and PR people.
But the esteemed originators should not be criticised for the failure of
/hoi polloi/ to understand their published proposal, and perhaps to read
it.



The proposal is to deflect the solar wind, without adding energy to it.
Therefore, the wind will press the magnet outwards; the magnet must be a
little inwards from L1, because of that and of radiation pressure.

--
(c) John Stockton, Surrey, UK. 拯merlyn.demon.co.uk Turnpike v6.05 MIME.
Merlyn Web Site < > - FAQish topics, acronyms, & links.

[dlzc]

Dear Yousuf Khan:

On Saturday, March 11, 2017 at 1:58:40 PM UTC-7, Yousuf Khan wrote:
> On 3/10/2017 9:37 AM, dlzc wrote:

...

> > Where does it get its power from? Won't be solar panels...
>
> And why not? Just scale up the number of solar panels to
> the required level to get to 1 or 2 Tesla.

Don't need intense, if you can get big.

> > ... which is not where you really want this
> > half-baked system. The particles this "magnetic
> > shield" is to protect you from, are not moving
> > at c. And Mars is still whipping around at a
> > good clip. The "wake" this system produces will
> > fall behind Mars, not *around* Mars. You'd need
> > to "drive" the object a little forward of the
> > stability point.
>
> The solar winds aren't travelling at c, they're
> only going between 300 - 750 km/s.
>
> https://en.wikipedia.org/wiki/Solar_wind

So the "shield" will have to be WAY forward. About 43 minutes forward:
https://plus.google.com/+JonathanLangdale/posts/h4HBjVDkS74

David A. Smith

[Serg io]

On 3/11/2017 3:54 PM, Dr J R Stockton wrote:
> In sci.astro message <o9p3o5$1gve$1...@gioia.aioe.org>, Wed, 8 Mar 2017
> 08:16:28, S Ergio <inv...@invalid.com> posted:
>
>> On 3/8/2017 6:42 AM, Yousuf Khan wrote:
>>> http://www.zdnet.com/article/nasa-proposes-artificial-magnetic-field-
>>> to-make-mars-a-second-home/
>
>>>> Green proposes that by placing a magnetic dipole shield at the Mars L1
>>>> Lagrange Point, a man-made magnetosphere sphere would cradle the
>>>> entire planet.
>
> Sort of. The dipole would shield the dayside of the atmosphere of Mars
> from the solar wind. By the way, in the past, at least some respected
> authors called L1 "L2" and L2 "L1". The proposal is not by Green; it is
> by Green /et al/.
>
>> how far away is Mars L1 Lagrange Point from Mars ?
>> about 141,000,000 miles.
> Very wrong.
>
>> how does magnetic field strength decline with distance ?
>> 1/d^2 ?
> For that, you need a monopole source. Point-dipole fields go as d^-3.

no, the fields vary as d^n where n is between 2 and 4, and n is also a
function of d, and orentation of the field.

>
>> so you need a magnet of at least 2*10^16 telsa ? ?
> The field strength at the magnet is of itself not important. It is the
> dipole moment which creates the far field.

field strength is *the key* design requirement, it drives the rest of
the design.

Referees should not have
> accepted <http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf> as it is,
> on those grounds.
>
>> why not just put it on the surface ? by the way, you will have to water
>> cool it too.
> Because that is a different, and not useful, idea; superconductors were
> discovered about 11 decades ago. Use currently-available high-
> temperature superconductors or better,

cooling is to lower copper coil losses, high temp superconducters are
not yet reliable for this, unless you have a url to a 1 T magnet using
one...

I think it gets down to watts, if 100 W it probably could be done, if
2000, probably not.

> and cool by shades as will be
> done for JWST;
allow the magnet to cool by radiation into the rest of
> the Universe.

but all that is limited by # Watts used, and if it is in sunlight, which
it is.

>
>
>> extra credit questions;
>>
>> 1. how much water is needed to cool magnet that generates a 1 T field
>> 100,000 miles away. (how is this water stored?)
> None; why 100,000 miles, as according to you L1 is at 141,000,000 miles.
> (in a zero-litre container).

you evade the question, how much heat is generated by the super-cooling
refrigeration unit for a 1 T field at 100,000 miles ? ( leave "T at
100,000 miles" as a variable) How many Watts does will the
refrigeration unit take to keep the unit cool? how many solar panels ?
how much storage capacity is needed ? How much refrigeration fluid is
lost each year ? (NASA has supercooled stuff in flight, limited life
time due to fluid loss)

>
>> 2. how much electricity in megawatts is required to run magnet, then to
>> pump water.
> None. But energy will be needed to create the dipole moment initially.

not so, see above, [Im sure NASA has info on this, effecient
supercooling refegeration, not sure about application to a magnet, but
they probably have a study on it]

>
>> 3. what % of partials will be deflected away and outside a 100 mile
>> zone on the surface around the magnet? (assume 98% speed of light)
> Wrong question.

yep, wrong question to you, as you do not have any answer.

>
>> 4. What type of partials will be hardly by magnet ?
> Parse failure. Try writing in your native language.

you engrlish teacher ? this is physics group.

>
>>>> While Green admits the idea is somewhat "fanciful,"
>>
>> this dude works at NASA ???
>
> Why not? NASA must have canteen staff, toilet cleaners, and PR people.
> But the esteemed originators should not be criticised for the failure of
> /hoi polloi/ to understand their published proposal, and perhaps to read
> it.

need more engineering before reclassifying from pipe dream to possable.

> The proposal is to deflect the solar wind, without adding energy to it.
> Therefore, the wind will press the magnet outwards; the magnet must be a
> little inwards from L1, because of that and of radiation pressure.
>

which directly goes to what the field strength should be, .

[Yousuf Khan]

On 3/11/2017 9:09 PM, dlzc wrote:
> Dear Yousuf Khan:
>
> On Saturday, March 11, 2017 at 1:58:40 PM UTC-7, Yousuf Khan wrote:
>> On 3/10/2017 9:37 AM, dlzc wrote:
> ...
>>> Where does it get its power from? Won't be solar panels...
>>
>> And why not? Just scale up the number of solar panels to
>> the required level to get to 1 or 2 Tesla.
>
> Don't need intense, if you can get big.

So either way, i.e. intense or big, how does that preclude using solar
panels?

>>> ... which is not where you really want this
>>> half-baked system. The particles this "magnetic
>>> shield" is to protect you from, are not moving
>>> at c. And Mars is still whipping around at a
>>> good clip. The "wake" this system produces will
>>> fall behind Mars, not *around* Mars. You'd need
>>> to "drive" the object a little forward of the
>>> stability point.
>>
>> The solar winds aren't travelling at c, they're
>> only going between 300 - 750 km/s.
>>
>> https://en.wikipedia.org/wiki/Solar_wind
>
> So the "shield" will have to be WAY forward. About 43 minutes forward:
> https://plus.google.com/+JonathanLangdale/posts/h4HBjVDkS74

43 minutes is the distance of the L1 away from Mars as far as the local
solar wind speed is considered. Or 3.5 light-seconds as far as the solar
light is concerned.

Yousuf Khan

[dlzc]

Dear Yousuf Khan:

On Sunday, March 12, 2017 at 10:13:05 PM UTC-7, Yousuf Khan wrote:
> On 3/11/2017 9:09 PM, dlzc wrote:

...

> > Dear Yousuf Khan:
> >
> > On Saturday, March 11, 2017 at 1:58:40 PM UTC-7, Yousuf Khan wrote:
> >> On 3/10/2017 9:37 AM, dlzc wrote:
> > ...
> >>> Where does it get its power from? Won't be
> >>> solar panels...
> >>
> >> And why not? Just scale up the number of
> >> solar panels to the required level to get
> >> to 1 or 2 Tesla.
> >
> > Don't need intense, if you can get big.
>
> So either way, i.e. intense or big, how does
> that preclude using solar panels?

Easier to do big, with lower light intensity, and fewer "expensive" materials.

> >>> ... which is not where you really want this
> >>> half-baked system. The particles this "magnetic
> >>> shield" is to protect you from, are not moving
> >>> at c. And Mars is still whipping around at a
> >>> good clip. The "wake" this system produces will
> >>> fall behind Mars, not *around* Mars. You'd need
> >>> to "drive" the object a little forward of the
> >>> stability point.
> >>
> >> The solar winds aren't travelling at c, they're
> >> only going between 300 - 750 km/s.
> >>
> >> https://en.wikipedia.org/wiki/Solar_wind
> >
> > So the "shield" will have to be WAY forward.
> > About 43 minutes forward:
> > https://plus.google.com/+JonathanLangdale/posts/h4HBjVDkS74
>
> 43 minutes is the distance of the L1 away from
> Mars as far as the local solar wind speed is
> considered. Or 3.5 light-seconds as far as the
> solar light is concerned.

The magnetic field does not stop light, only charged particles. So solar wind speed, is what needs to be figured in.

David A. Smith

[Yousuf Khan]

On 3/13/2017 10:14 AM, dlzc wrote:
> Dear Yousuf Khan:
>
> On Sunday, March 12, 2017 at 10:13:05 PM UTC-7, Yousuf Khan wrote:
>> So either way, i.e. intense or big, how does
>> that preclude using solar panels?
>
> Easier to do big, with lower light intensity, and fewer "expensive" materials.

So go big. They'll figure out the best way to approach it.

>>> So the "shield" will have to be WAY forward.
>>> About 43 minutes forward:
>>> https://plus.google.com/+JonathanLangdale/posts/h4HBjVDkS74
>>
>> 43 minutes is the distance of the L1 away from
>> Mars as far as the local solar wind speed is
>> considered. Or 3.5 light-seconds as far as the
>> solar light is concerned.
>
> The magnetic field does not stop light, only charged particles. So solar wind speed, is what needs to be figured in.
>
> David A. Smith

The article you linked to is from 2011, and it's about a totally
different issue. It's about an early warning system for solar winds, so
putting a satellite at the L1 would encounter the solar wind 43 minutes
before Mars itself does. But due to the higher speed of light, which
gets to Mars in 3.5 seconds, you have 43 minutes - 3.5 seconds of early
warning about it.

The issue here is not about early warning, but about redirecting the
solar winds completely from Mars. So early warning really has no bearing
on anything here, except that if the parameters of the magnetic shield
need to be adjusted, you have about 7 seconds of turn around time to
react from Mars.

Yousuf Khan

[dlzc]

Dear Yousuf Khan:

On Wednesday, March 15, 2017 at 8:41:45 PM UTC-7, Yousuf Khan wrote:
> On 3/13/2017 10:14 AM, dlzc wrote:
> > On Sunday, March 12, 2017 at 10:13:05 PM UTC-7, Yousuf Khan wrote:
> >> So either way, i.e. intense or big, how does
> >> that preclude using solar panels?
> >
> > Easier to do big, with lower light intensity, and
> > fewer "expensive" materials.
>
> So go big. They'll figure out the best way to
> approach it.

You have a lot of faith in "them".

> >>> So the "shield" will have to be WAY forward.
> >>> About 43 minutes forward:
> >>> https://plus.google.com/+JonathanLangdale/posts/h4HBjVDkS74
> >>
> >> 43 minutes is the distance of the L1 away from
> >> Mars as far as the local solar wind speed is
> >> considered. Or 3.5 light-seconds as far as the
> >> solar light is concerned.
> >
> > The magnetic field does not stop light, only
> > charged particles. So solar wind speed, is
> > what needs to be figured in.
>

> The article you linked to is from 2011, and
> it's about a totally different issue. It's about
> an early warning system for solar winds, so
> putting a satellite at the L1 would encounter
> the solar wind 43 minutes before Mars itself
> does. But due to the higher speed of light,
> which gets to Mars in 3.5 seconds, you have
> 43 minutes - 3.5 seconds of early warning about
> it.
>
> The issue here is not about early warning, but
> about redirecting the solar winds completely
> from Mars. So early warning really has no
> bearing on anything here, except that if the
> parameters of the magnetic shield need to be
> adjusted, you have about 7 seconds of turn
> around time to react from Mars.

The solar wind takes 43 minutes to reach the orbit of Mars. So a "shadow" in solar wind created by an object at the L1 point, crosses Mars orbit 61,920 km BEHIND Mars. Mars is only 7000 km in diameter.

David A. Smith

[Yousuf Khan]

I don't get what you're saying here! Presumably, they can angle the
magnetic field far enough in advance to aim the solar wind "shadow",
right as Mars is passing through it.

Yousuf Khan

[dlzc]

Dear Yousuf Khan:

On Saturday, March 18, 2017 at 1:10:20 AM UTC-7, Yousuf Khan wrote:
> On 3/16/2017 10:25 AM, dlzc wrote:
> > On Wednesday, March 15, 2017 at 8:41:45 PM UTC-7, Yousuf Khan wrote:
> >>>
> >>> The article you linked to is from 2011, and
> >>> it's about a totally different issue. It's about an
> >>> early warning system for solar winds, so putting a
> >>> satellite at the L1 would encounter the solar wind
> >>> 43 minutes before Mars itself does. But due to the
> >>> higher speed of light, which gets to Mars in 3.5
> >>> seconds, you have 43 minutes - 3.5 seconds of early
> >>> warning about it.
> >>>
> >>> The issue here is not about early warning, but about
> >>> redirecting the solar winds completely from Mars. So
> >>> early warning really has no bearing on anything
> >>> here, except that if the parameters of the magnetic
> >>> shield need to be adjusted, you have about 7 seconds
> >>> of turn around time to react from Mars.
>
> > The solar wind takes 43 minutes to reach the orbit
> > of Mars. So a "shadow" in solar wind created by an
> > object at the L1 point, crosses Mars orbit 61,920 km
> > BEHIND Mars. Mars is only 7000 km in diameter.
>

> I don't get what you're saying here!

Sure you do.

> Presumably, they can angle the magnetic field far
> enough in advance to aim the solar wind "shadow",
> right as Mars is passing through it.

Only with "new physics". Either they make a symmetric field 20 times the diameter of what is required (because we only know how to make symmetric fields), or they add a small amount of energy to keep the source that far ahead of Mars.

David A. Smith

[Yousuf Khan]

On 3/18/2017 12:05 PM, dlzc wrote:
>> Presumably, they can angle the magnetic field far
>> > enough in advance to aim the solar wind "shadow",
>> > right as Mars is passing through it.
> Only with "new physics". Either they make a symmetric field 20 times the diameter of what is required (because we only know how to make symmetric fields), or they add a small amount of energy to keep the source that far ahead of Mars.

You can do it with multiple satellites each orbiting around the L1
point, they can all be adjusted individually and oriented individually.