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#1 2017-11-27 00:03:21

Lake Matthew Team - Cole
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Omaha Shield: radiation protection systems for Unlimited Mars Career

487px-Bronze_votive_shield.jpg

Omaha Shield: a triad of radiation protection systems, to enable the Unlimited Mars Career (UMC)

November 16, 2017 – A jury has selected the Lake Matthew Team's artificial geomagnetic field proposal as the winner of the Innovation in Science award under the rubric of Hewlett-Packard's Mars Home Planet initiative. The jury's selection recognizes cosmic ray protection on open ground as a vital innovation. The proposed design protects a crater 9 km in diameter. This scale matches the ambition of HP Mars Home Planet to protect "1 million people... living, working and moving around on Mars".

The proposed "Omaha Field" is the third of three components of the Lake Matthew Team's "Omaha Shield" design; the last component to be specified and quantified. The Omaha Field aims to fill a final gap in end-to-end mission radiation protection, thereby enabling the "Unlimited Mars Career (UMC)". The team's UMC goal is to ensure that no crewmember suffers a career-limiting radiation dose, over any career duration on Mars. McGirl et al. 2016 gives one statement of the envisioned challenge.

Omaha Shield: a Protective Triad

1. Omaha Crater

MATT's Omaha Crater is a region of warm bedrock sited within icy terrain, giving abundant water for facility use. Treated water gives full cosmic ray protection to pressurized facilities. The water covers facility domes to an average depth of 5 m, sufficient to block essentially all cosmic ray protons and most other ionizing radiation, while admitting sufficient sunlight for natural-light greenhouses.

2. Omaha Trail

The proposed Omaha Trail facilities offer radiation protection to crews in transit between Earth and Mars. For each crewed mission 130 tons of water is harvested from Deimos, to be shuttled between planets as a cosmic ray shield that's dumped prior to landing. En route to Mars the water shields against ~90% of solar flare protons, and many other cosmic rays. Also the proposed tether-rail launcher at Deimos increases the speed of flights to Earth, to reduce radiation exposure even further on the way home. On the Omaha Trail, solar storm shelters should become a thing of the past.

3. Omaha Field

An artificial local geomagnetic field is proposed, with similarities to a previous NASA idea for an artificial martian magnetic shield. This proposed field is smaller: it protects Omaha Crater's open ground surface from cosmic rays at close range. The design applies technology from superconducting power lines, superconducting solenoids, and carbon nanotube cables. Magnetostatic modeling indicates that the field can deflect all solar storm protons, nearly all solar flare protons, and more than half of galactic cosmic ray protons. The Omaha Field system could be installed at other sites that are also surrounded by high terrain. Moreover, a more portable version of the system may be feasible, for self-deployment at elevated and open-plain excursion sites. Portability would extend the reach of the Omaha Field across the entirety of the martian surface...

Last edited by Lake Matthew Team - Cole (2017-11-27 00:04:08)

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#2 2017-11-27 01:58:33

louis
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Great approach - we need people to think about this problem and find doable solutions.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#3 2017-11-27 02:16:56

kbd512
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

If you want water for a colony, then locate some ice in the Martian regolith.  It's a lot easier than shipping it to Mars from Deimos.  The company working on the rocket featured prominently on your website that you want to use to ship water to Mars is counting on that.  Sufficient radiation protection can be had by burying habitat modules.  Boring machines can dig tunnels as deep as is required using solar panels or small fission reactors.  The solutions that tend to actually get implemented are of a practical nature.  There's no practical reason to crash asteroids into Mars or to ship water to Mars from Deimos.  It may be a fun thought experiment, but all practicality ends there.

Congratulations on winning the award.  Your team now has a gold star next to its name.  It's very creative, but needlessly expensive and complicated.  We've had nothing but thought experiments pertaining to sending humans to Mars precisely because our scientists are constantly trying to prove how smart they are, rather than how practical and frugal they are.  I'm impressed with the detail and ingenuity of your solutions and this critique is in no way intended to disparage your work or discourage the cleverness of your team members.

We're simply not going to colonize Mars in the next several decades unless we're exceptionally practical in our approaches to the very real problems of providing sufficient food, water, and environmental protections.  That may not be what your team wants to hear, but that doesn't make my admonishment any less applicable.  You clearly have some smart people on your team and I know your team can come up with something even better from a cost and complexity standpoint.

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#4 2017-11-27 11:01:37

Lake Matthew Team - Cole
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

kbd512 wrote:

If you want water for a colony, then locate some ice in the Martian regolith.  It's a lot easier than shipping it to Mars from Deimos.

The selected site for Omaha Crater is rich in ice; hence the selection.  MATT impact provides immense heat energy, which is very useful.  There's nothing especially impractical about that.  Invention details aim for practical execution.

Note that Deimos water would not be shipped to Mars.  That water would serve on the Omaha Trail primarily as shielding material, for ships in transit.  They'd dump the shield before EDL, as the water isn't needed after transit.

Also, have you taken a look at Dr. Lades' work on the Mars Lift design?  It's the first design that's actually shown to avoid Phobos, passively, and while using plausible CNT material.  Also our unpowered "rappeller" concept aims to further simplify elevator operation, relative to powered designs.

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#5 2017-11-27 12:07:20

kbd512
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

After we acquire the technology for space elevators and lasers that can move asteroids onto a collision course with Mars, we can probably still dig holes in the ground for less money.  Humans have been digging holes for a long time.  We're pretty good at it, too.  Whenever someone wants to start a second colony on Mars, is everyone currently living on Mars going to duck and hope that the trajectory calculations are correct?  Assuming it works, it's still an unnecessary risk and expenditure of resources.

Ships that don't have to carry 130t of water with them to and from Mars will likely weigh far less, require far less propellant, and be easier to get to and from Mars fast enough that we really don't need to worry about spending a few months in deep space.  At least, that's the plan that SpaceX has put forward and the impetus behind better in-space propulsion methods currently funded by NASA.  Incidentally, rocket engines work quite well right now without invoking technology that can only plausibly be made to work.  We may also want to use one of those space elevators on Earth before we concern ourselves with building one on Mars.  We could probably source that 130t of water from Earth a lot easier than Deimos if we were intent on using water shielding.

Anyway, just some of my thoughts about practicality.  Take it for what it's worth.  Your team's plan may be entirely feasible using technology that doesn't exist, but it seems like a rather costly way to create radiation shielding and provide a water source for a colony.  Some truly great ideas have never left the drawing board as a function of what they would cost.

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#6 2017-11-27 13:45:46

Lake Matthew Team - Cole
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

kbd512 wrote:

After we acquire the technology for space elevators and lasers that can move asteroids onto a collision course with Mars, we can probably still dig holes in the ground for less money.  Humans have been digging holes for a long time.

Warm 9 km holes aren't so easy to dig on Mars.

And the laser system for small-body deflection already exists of course.  We give it a job.

scalingmw2.png

Last edited by Lake Matthew Team - Cole (2017-11-27 14:33:05)

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#7 2017-11-27 14:39:05

kbd512
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Why do we need to dig 9km holes on Mars?

Those SpaceX rockets only carry 100 people, so we need 10,000 flights just to deliver the people and other infrastructure that doesn't exist.  That could take quite awhile as long as launch opportunities only occur every 2 years.  I think we'd need a bigger ship or a fleet with more ships than the US Navy if we want to start a colony with a million people in say, 20 years.  Where's the money for that?

I've never seen or heard of an asteroid being redirected using a laser.  I'm sure we could do it with enough money and development time, but we never have and I seriously doubt it's something we could do with spare parts laying around at ATK.  Maybe all the individual pieces of flight hardware work in a lab somewhere, but then we need all those pieces assembled into a functional device and tested.  Where's the money for that?

If we're spending money on all this extra stuff, as cool as it is, guess what won't receive enough funding?  We can't even properly fund SLS development to make its target launch date.  No humans that we know of have been to Mars and we're trying to send a million people there before the first person has set foot on the planet.  PowerPoint presentations with great ideas using future technology won't change that.  The rubber needs to meet the road somewhere in order for this colonization idea to gain traction.  That starts with initial exploration to confirm resource availability and a test colony.  If you want your team to have maximum impact, then develop a realistic starter colony idea to prove that some basic concepts will work.

Even the very best ideas require adequate funding and prior to providing the hundreds of billions of dollars required to construct an off world colony, someone will inevitably want proof of concept.  I wouldn't send one person unless I was reasonably sure that everything would function as intended, but that's just me.

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#9 2017-11-27 20:12:47

Lake Matthew Team - Cole
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

kbd512 wrote:

Why do we need to dig 9km holes on Mars?

Simply put, to cut the cost and difficulty of Mars facilities very significantly.  Radiation protection, giant habs, continual power, food self-sufficiency, ISRU facilities, precious metal mining -- all are much easier with Omaha Crater resources. 

Escaping the scaling law of pressure vessels, with large subaqueous habs, is by itself a strong justification.  Imagine the cost reduction, when one cargo can build a hab of 2 million cubic meters, as compared to today's limit of a few thousand cubic meters. 

Game-changer.  That's why we did the work.

kbd512 wrote:

I've never seen or heard of an asteroid being redirected using a laser.

Do check out that linked reference paper, up above.  NASA / UCSB have done a lot of work to realize the DE-STARLITE tech, specifically for deflection of small bodies.  It's just sitting there, waiting.

kbd512 wrote:

The rubber needs to meet the road somewhere in order for this colonization idea to gain traction.

Surely.  It will really meet the road if a leader commits his team to ramming the terraformer into Mars.

Where could we hope to find a bigger game-changer than that?

Last edited by Lake Matthew Team - Cole (2017-11-27 22:09:30)

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#10 2017-11-27 21:46:32

RobS
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Could you explain "proposed tether-rail launcher at Deimos"? It sounds like it wouldn't be on the surface of the moon, but above it, presumably so it can be pointed in the right direction for launching things toward Earth. That sounds like a great way to reduce transit costs.

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#11 2017-11-27 22:27:02

Lake Matthew Team - Cole
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

RobS wrote:

Could you explain "proposed tether-rail launcher at Deimos"? It sounds like it wouldn't be on the surface of the moon, but above it, presumably so it can be pointed in the right direction for launching things toward Earth. That sounds like a great way to reduce transit costs.

Hi.  Yes, the aim is to improve transit, by cutting propellant, transit time, cosmic ray exposure, etc.

DRL cabling extends from Deimos through L2, for mass-efficiency and tensioning. 

Delta-V 1 km/s inbound, for optimal Mars periapsis gravity-assist.

Some DRL slides in:

BIS Omaha Trail presentation Nov 2017.

ISEC Omaha Trail presentation Aug 2017.

OmahaTrail5-768x326.png
DRL extending from Deimos through L2 at lower right.

Last edited by Lake Matthew Team - Cole (2017-11-28 12:54:31)

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#12 2017-12-01 23:43:28

RobS
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Thank you. I suspect the articles about Deimos being ice-rich are incorrect, unfortunately. The moon's low density is more easily explained by a lot of interior void space, which suggests that both moons are rubble piles. Rubble piles are assembled through collision and collision would probably heat the material, causing loss of volatiles. I hope I am wrong about that. The spectral signatures of both moons do not fit any common asteroid type, probably because the moons are covered by material blasted off Mars, and the impact of that material would also deplete the moons of volatiles.

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#13 2017-12-02 00:21:10

RobertDyck
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

RobS wrote:

The spectral signatures of both moons do not fit any common asteroid type

I read they are. They're carbonaceous chondrite. That's the most common asteroid type in near-Earth space, and the one with ice.

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#14 2017-12-02 07:49:04

RobS
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

I've seen different understandings about their spectral signatures. They may be a mix of carbonaceous chondrite and Martian debris. But they are low in density and have a lot of void space. Maybe the collisions that shaped both moons caused some volatile release, and some of it froze as ice in the void space. I hope there's a lot of ice there, but it is not clear. Both moons share the inclination of Mars's axis, so there are no cryogenic cold traps at the poles.

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#15 2017-12-02 12:37:36

GW Johnson
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

It's fine (and fun) to dream up all these ways of doing things better,  utilizing resources predicted to be there at these various destinations.  The point I have tried to make in multiple threads on these forums is:  "you inherently do not know that those resources really are there,  until you actually go there and dig or drill".  Applies to Mars,  its moons,  asteroids,  comets,  and any other planet or moon. 

The feedback I keep getting is nothing but arguments-from-authority:  this or that paper or prestigious name says the buried resource stuff is there.  It's all based on remote sensing in one form or another,  precisely because no human has ever actually been there and dug or drilled.  I'm an old guy,  I've seen a lot of claims based on remote sensing about "what is there" over the decades,  AND 100% OF THEM HAVE BEEN WRONG at one level or another,  some wildly wrong,  when we actually sent something there and looked up close. 

So,  please forgive me if I discount entirely arguments-from-authority.  I know better than that.  No paper or prestigious name has any credibility worth risking lives upon.  Period.  History demonstrates that quite conclusively.

Now,  that being said,  are there any resources on Deimos or Phobos that we could really use effectively?  Might,  or might not,  be.  Point is,  we don't know,  and CANNOT know for sure,  until we go and dig or drill,  because we are talking about buried resources here!  You cannot directly observe them at all,  remotely.  You have to infer they are there,  from your remote measurements of what you can see exposed to view,  and both the inferring and the remote measurements are fraught with possibilities for error.  At one level or another,  they always will be. 

Volatiles,  if there,  could be remade into energy,  life support,  or propulsion materials,  yes.  But if they're not,  and you had counted on them being there,  you just killed your space crew!  There is nothing as demonstrably expensive as a crew killed by a bad management decision.   Same warning goes for Mars,  the moon,  any of the asteroids,  and the comets and other planets and moons.  It's just badly flawed thinking to count on inferred resources for the first trip there,  anywhere.

As for building things in space from local mass on these objects,  the technology to turn minerals and carbon debris into real engineering materials DOES NOT EXIST yet.  Not even the detailed science exists,  only vague notions of conservation of mass. 

How do you turn a simple rock and/or some charcoal-like debris into a piece of bar stock or sheet with the properties of an aluminum or steel?  NO ONE ALIVE TODAY CAN ANSWER THAT QUESTION!  There's a very good reason we don't ask stone materials to support tensile loads in bridges and other structures.  Yet that is exactly what we have to have (tensile strength) to build mass drivers and pressurized structures like space habitats,  etc.

Sometime in the future an unpredictable interval from now,  we may know how to do such things with nature's materials as they exist in space.  Once that happens,  wonderful things become possible.  It's fun to dream about them,  yes.  But foolish to propose it as something we might actually do in our lifetimes.

If you want to live to see men on Mars,  your better choices are small variations on what we already do today.  Mixing from-scratch technology development into a go-fly project never works:  when you do it,  you never fly.  You have to do both,  but do them separately.  Advice from an old retired hand who was very successful in engineering development work.

What's ready right now is chemical rocketry at any scale,  and electric propulsion at small scale.  It's not a major deal to scale up electric propulsion,  but somebody had better get on with that job,  as it takes some years to accomplish. 

RTG power is too weak to run a manned base,  we'll need a real reactor,  and if we're making supplies from local resources,  it'd better be a damned big one,  or a whole bunch of medium-sized ones.  A true base operation will need hundreds to thousands of KW of electricity.  I think we’re talking about 100 KW electric per unit here,  even initially.  Larger still eventually. 

Our life support is imperfect in its recycling,  which means extra packed supplies and make-up shipments from Earth are required,  until we learn how to do that job better at some indeterminable date in the future.  So deal with it,  and plan on it.  It means bigger spacecraft and more regular supply flights.  It pretty well rules out minimalist min-thrown-mass mission designs,  doesn't it? 

Which is really why Musk's BFR vision starts looking rather attractive,  at least from mission 2 onward.  He hasn’t yet addressed landing on unprepared ground with an inherently-unstable tall vehicle.  But he’s fine for prepared landing fields. 

Our discoveries about microgravity diseases (plural!) show that more than a year at a time exposed to zero gee is not very practical at all.  They also show we haven't yet discovered and understood all the deleterious effects.  The message is getting fairly clear:  avoid the risk and spin the damned transit vehicles. 

Use the transits with artificial gravity as the recovery time from low-gravity exposures on Mars or the moon (or anywhere else).  That way the crews are always in best health for the rigors of arrival.  For high-velocity entries from deep space,  we are talking 11+ gees at Earth,  so fitness is required.  Period.  Deal with it:  it means no zero-gee transits to or from.

For radiation protection,  we already know how to hide behind a passive shield,  and what kinds of materials to make those passive shields from,  and about how much is required.  We've been doing it for almost a century in various nuclear efforts at one scale or another here on Earth.  There's some science available for electromagnetic shielding,  but no workable technology and hardware yet available for general use. 

If you want to fly "now" (meaning within our lifetimes),  go with the passive shielding.  Otherwise,  you will wait some undetermined interval until the electromagnetic shielding hardware that is ready-to-apply becomes available. 

Passive shielding is very heavy,  and will require very innovative approaches to spacecraft design to take maximum advantage of structures and materials you already have to have for other reasons.  It is quite likely this will rule out most of today's vehicle concepts in favor of the orbit-to-orbit transport concepts of the 1950's.  That's quite the different mission architecture.  Deal with it.

I don't see NASA and "old space" dealing with any of this,  or any of the other countries’ agencies.  "New space" in the US is only just beginning to deal with some of it.   They haven’t got very far yet.

I know these thoughts will be “unpopular” with many on these forums,  but they are very realistic questions and thus very realistic design advice.  Any deep space manned missions must address these things,  or else crews will die needlessly. 

I don’t see these issues addressed yet.  So far,  that emperor is still as naked as a peeled egg.

GW


GW Johnson
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"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#16 2017-12-02 12:46:33

RobS
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Thanks, GW, that's the sort of bracing reminder of reality we need from time to time!

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#17 2017-12-02 13:22:11

SpaceNut
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

All said we need a demonstrator mission to the moons of mars to determine that actual content of resources to which we already have some cost models from Nasa launched missions of this type. We are not talking discovery mission costs but scout to which are much lower. We are not talking the billion dollar missions that last forever either.

So we need to drill and core and get real answers as GW said flight ready means not in the R&D shops but are in the fabrication for use.
We already have the can vs. Inflateable question answer for radiation levels so send up the trial hardware field generators and get real
answers.

We have the answer as to what effect exercise has on the body but nothing for the gravity numbers for mars or long term stays on the moon. So get the artifical gravity tests going at the station make more than a little bit of sense to fill in that partial answer.

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#18 2017-12-02 16:22:33

Lake Matthew Team - Cole
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

GW Johnson wrote:

It's fine (and fun) to dream up all these ways of doing things better,  utilizing resources predicted to be there at these various destinations.  The point I have tried to make in multiple threads on these forums is:  "you inherently do not know that those resources really are there,  until you actually go there and dig or drill".  Applies to Mars,  its moons,  asteroids,  comets,  and any other planet or moon. 

The feedback I keep getting is nothing but arguments-from-authority:  this or that paper or prestigious name says the buried resource stuff is there.  It's all based on remote sensing in one form or another,  precisely because no human has ever actually been there and dug or drilled...

Lumping us in with less informed [straw-man?] posters is inappropriate.  Rejected.  We do understand the literature, warts and all, and we apply it, even in our own novel designs.  As for Deimos:  We quantified the Deimos possibilities in forum, not you.  E.g. post 1, post 2.  That's not fallacious argument from authority, that's knowing more than you.

Anyone taking your own posts at face value would have been badly misinformed on that topic.  So before posting again, read our refs, and read something more; maybe then you'll have some information or self-correction for the thread.

And do keep it on-topic.  This is the thread for the new Omaha Shield proposal, specifically; not for rehashes of old and irrelevant text.

Last edited by Lake Matthew Team - Cole (2017-12-02 16:44:02)

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#19 2017-12-02 17:50:15

SpaceNut
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Gw the data from spectral observation has been found to have a near acuracy; from placing the rovers on mars as our knowledge of mars was based on the same methods.

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#20 2017-12-02 17:55:48

GW Johnson
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Lake Matthew Team - Cole:

None of us old codgers take well to being lectured by arrogant young whipper-snappers.  Mind your tongue,  please. 

I have seen papers from equally-credentialled experts that say things quite different from what the papers you cite say about water on Deimos,  or not,  its history and formation,  etc.,  etc.  Because of that difference,  I trust none of them.  Period.  I trust ground truth only.  As should you,  when lives are at stake.  Not to do so is unethical in the extreme.

As far as I am concerned,  speculations about what water might be here or there,  anywhere in the solar system (but Earth),  are all just that:  scientific speculation,  and thus effectively bullshit to boot. If these scientists are wrong,  then they are embarrassed,  but they are not killed by their mistake. 

If instead a crew goes there supplied based on what these scientists say,  and they turn out to be wrong,  then that crew dies.  There is quite a difference.  I am very disappointed in you for not seeming to know the difference between those two scenarios,  or that you ignore (or perhaps are unaware of) the fact that there are other views about what exists on Deimos in the literature. 

I need not cite such papers for you,  go find them yourself.  I am not a name-dropper,  I don't have to be.  I have seen many dozens of papers in this topic (and countless others) in recent years in peer-reviewed journals such as AAAS's "Science". Many have proven wrong and been superseded.  Few have been so egregiously wrong as to be retracted.  I think that pattern,  in and of itself,  says something.  What it says is that the very best estimates we can make usually prove to be very wrong,  once ground truth is obtained. 

As for straying from the topic,  I did NOT.  I responded directly to posts 12,  13,  and 14 just above.  If anybody strayed,  it was them.  Although,  I think the topic really is relevant,  even if this is the wrong thread for it.  I do NOT appreciate being accused of something I did not do.

Spacenut:

Remote sensing said to be groundwater-as-ice on Mars is inferred from detecting subsurface hydrogen atoms,  not water molecules.  It is inferred (not factually determined) that such hydrogen is water and not some other hydrogen-containing compounds.  It is also inferred that it is ice,  and not some other form. 

Whether these are accurate inferences is what I am pointing out:  we don't know.  We cannot know until we go there and actually dig or drill.  The history of ground truth since before 1963 starting with Surveyor on the moon is that most such estimates were not only wrong,  but often egregiously wrong. 

GW

Last edited by GW Johnson (2017-12-02 18:05:58)


GW Johnson
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"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#21 2017-12-02 18:13:42

SpaceNut
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Hopefully a comparison of mars spectral data versus that to which rover have confirmed would be enough to say that we can be more trusting but with caution to it until confirmed.

https://en.wikipedia.org/wiki/Scientifi … er_mission
Coordinated analyses of orbital and spirit rover data to characterize surface materials on the cratered plains of Gusev Crater, Mars or same abstract here
https://asu.pure.elsevier.com/en/public … o-characte

http://www.themarslab.org/app/uploads/2 … ryV2-2.pdf
http://www.spectroscopyonline.com/spect … red-planet

This is what we have done thus far for mars.

Back to field generation and protection to which the in space transit and the on surface are different and require different resolutions.

When we look at earth we have a dynamic north south polar magnetic field and we are shielded via the van alen belts to which they are both very weak but there so re-enforcing these would or should be a goal as well.

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#22 2017-12-02 18:58:35

Lake Matthew Team - Cole
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

GW Johnson wrote:

I need not cite such papers for you,  go find them yourself.  I am not a name-dropper,  I don't have to be.  I have seen many dozens of papers in this topic...

Dozens.  Wow.

GW Johnson wrote:

I trust ground truth only.  As should you,  when lives are at stake.  Not to do so is unethical in the extreme.

As though no one had ever thought of these things, and more constructively. 

You should step away from the old punching bag; there are new things to talk about.

Last edited by Lake Matthew Team - Cole (2017-12-02 19:16:01)

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#23 2017-12-02 19:45:31

RobertDyck
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

Talking of "splash of cold water", there's something else I would like confirmed. Mars Global Surveyor (MGS) used remote sensing to detect surface minerals. The paper published in Science had an addendum only available online. That addendum included surface minerals they calculated. It included serpentine and actinolite. They're important because when crushed so the mineral crystals form fibres, that's asbestos. And since this was from spectra of Mars surface, that implies surface fines contain that. However, I haven't heard any confirmation from any lander or rover. As GW keeps saying, we need ground truth. Has anyone seen these from one of the rovers?

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#24 2017-12-02 21:08:53

RobS
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Re: Omaha Shield: radiation protection systems for Unlimited Mars Career

I haven't heard anything about asbestos, Robert. The best way to get that question answered would be to ask an expert, perhaps at the Mars Society annual meeting. Steve Squires sometimes attends, for example. But even if the Martian fines don't have asbestos in them, they are so fine that they are regarded as potentially carcinogenic.

My impression is that the two rovers have provided a lot of ground truth for the orbital remote sensing data. As a result we can identify smectite and all sorts of other clay minerals from orbit; calcium carbonate; iron silicate minerals; in short, many of the most common Martian surface materials. But that actually reinforces GW Johnson's point about water, because many of the clays are hydrated and therefore have hydrogen in them. One can heat them up and drive off the water, but it's easier to obtain liquid water from ice, obviously.

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