# Mars in 90 days



## Brian G Turner (Oct 20, 2004)

Advocates of a propulsion idea for spacecraft claim that it would enable a 90-day round trip to Mars.   Using current technology, it would take astronauts about 2.5 years to travel to Mars, conduct their mission and return to Earth, US scientists estimate. 

  It would use a space station to fire a beam of magnetised particles at a solar sail mounted on a spacecraft. 

  This plasma beam would then make use of repulsive forces to propel the spacecraft along at high speeds. 

http://news.bbc.co.uk/1/hi/sci/tech/3755988.stm


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## Morning Star (Oct 20, 2004)

Forgive me for thinking this...but this really reminds of the old "Trip to the Moon" novel. I think it was by Jules Vern, they still made a movie out of it. It involved the theory of firing the shuttle out of a cannon at very, very high speeds.


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## dwndrgn (Oct 20, 2004)

Actually it sounds _very_ much like what is described in 2001:A Space Odyssey.


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## Princess Ivy (Oct 21, 2004)

sorry, but how do they stop? I mean, according to most science fiction that i've read, retros are fired to break accellaration, however that usualy takes a period of months, apparently if they break to fast they end up going staight back. my understanding of the sciences involved is very limited


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## polymorphikos (Oct 21, 2004)

I think they'll decellerate using a second beam at the same rate as the initial acceleration, from the halfway mark. If I got that right, since the article confused me slightly due to sleepiness.


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## Maryjane (Oct 21, 2004)

2  | >> Continue with this story >


but how do they stop? I mean, according to most science fiction that i've read, retros are fired to break accellaration, however that usualy takes a period of months, apparently if they break to fast they end up going staight back. my understanding of the sciences involved is very limited


_That's true Princes Ivy I think it's a couple weeks before they reach said planet they begin giving retros short bursts to slow it down and when it gets close enough to the planet the gravitational pull along with the retros to position the ship into a syncronus orbit around the planet. For returning it again uses the retros with short bursts to position the ship then fire engins for the spiraling trajectory away from the planet._

_I have heard of a few alternate propulsion systems in the think tank stage and some have even been applied like this diagram shows. _








The glich with this plan is that a plasma driven rocket is slower on the exceleration then the conventional rockets but once it gets goin it'll move like a scolded dog and in astronomical terms that's much faster then conventional rockets  another bonus with plazma fule is last much longer then traditional rocket fule. Then we will have this means of transporting the parts to build the first ship to Mars right in orbit here.

LBUQUERQUE, NEW MEXICO -- Make way for the ultimate high-rise 
            project: the space elevator. Long viewed as science fiction 
            "imagineering", researchers are gathering momentum in their pursuit 
            to propel this uplifting concept into actuality. 
            Still, the mental picture needed to grasp the elevator to space 
            idea…well, you can't be weak of mind. 
            Forget the roar of rocketry and those bone jarring liftoffs, the 
            elevator would be a smooth 62,000-mile (100,000-kilometer) ride up a 
            long cable. Payloads can shimmy up the Earth-to-space cable, 
            experiencing no large launch forces, slowly climbing from one 
            atmosphere to a vacuum. 
            Earth orbit, the Moon, Mars, Venus, the asteroids and beyond - they 
            are routinely accessible via the space elevator. And for all its 
            promise and grandeur, this mega-project is made practical by the 
            tiniest of technologies - carbon nanotubes. 
                  TECH WEDNESDAY
                        Visit SPACE.com to explore a new technology feature each 
                        Wednesday.
                        >>Go to Tech Wednesday archive page 


                           Images


                        For a space elevator to function, a cable with one end 
                        attached to the Earth's surface stretches upwards, 
                        reaching beyond geosynchronous orbit, at 21,700 miles 
                        (35,000-kilometer altitude).


                         Twenty tons of cable and reel would be kicked up 
                              to geosynchronous altitude by spacecraft to get 
                              the project started.



                         Super-strong carbon nanotubes may make space 
                              elevators feasible. Click-to-enlarge.



                         Space Elevators could be established on other 
                              planets, like Mars, to assist in their 
exploration.


                           Related SPACE.com STORIES

                        Space Elevator: Next Stop, Earth Orbit


                        Moon Base Would Scan The Sky, And Deflect Threats To 
                        Earth


                        Advanced Projects Map Future of Spaceflight


                        NASA To Go Nuclear; Spaceflight Initiative Approved


                           TODAY'S DISCUSSION
                        What do you think of this story? 
                        >>Uplink your views 


            Seen as an engineering undertaking for the opening decades of the 
            21st century, the space elevator proposal was highlighted here 
            during the 2002 Space and Robotics Conferences, held March 17-21, 
            and sponsored by the Aerospace Division of the American Society of 
            Civil Engineers.
            Thought experiment 
            Science fiction writers have been deploying space elevators for 
            years. 
            Space visionary, Arthur Clarke, centered his novel of the late 
            1970s, The Fountains of Paradise, on the notion. Also, among other 
            writers, Kim Stanley-Robinson's Red Mars noted the soaring splendor 
            of an elevator to space. Furthermore, the scheme has bounced around 
            technical journals for decades. Some call it a "thought experiment", 
            but others point out that space exploration B.C. -- "Before Cable" 
            -- will pale contrasted to what's possible within ten to fifteen 
            years.
            "Even though the challenges to bring the space elevator to reality 
            are substantial, there are no physical or economic reasons why it 
            can't be built in our lifetime." That's the matter-of-fact feeling 
            of physicist, Bradley Edwards of Eureka Scientific in Berkeley, 
            California, but carrying out heavy lifting design work in Seattle, 
            Washington.
            Edwards told SPACE.com that he's been wrapped up in space elevator 
            work for some three years, supported by grants from NASA's Institute 
            for Advanced Concepts (NIAC) program. "I'm convinced that the space 
            elevator is practical and doable. In 12 years, we could be launching 
            tons of payload every three days, at just a little over a couple 
            hundred dollars a pound," he said. 
            "In 15 years we could have a dozen cables running full steam putting 
            50 tons in space every day for even less, including upper middle 
            class individuals wanting a joyride into space. Now I just need the 
            $5 billion, Edwards added.
            And so it grows
            For a space elevator to function, a cable with one end attached to 
            the Earth's surface stretches upwards, reaching beyond 
            geosynchronous orbit, at 21,700 miles (35,000-kilometer altitude). 
            After that, simple physics takes charge.
            The competing forces of gravity at the lower end and outward 
            centripetal acceleration at the farther end keep the cable under 
            tension. The cable remains stationary over a single position on 
            Earth. This cable, once in position, can be scaled from Earth by 
            mechanical means, right into Earth orbit. An object released at the 
            cable's far end would have sufficient energy to escape from the 
            gravity tug of our home planet and travel to neighboring the moon or 
            to more distant interplanetary targets.
            Putting physics aside the toughest challenge has been finding a 
            super-strong cable material. "That's what has kept this idea in 
            science fiction for 40 years," Edwards said. But the right stuff in 
            terms of cable material is no longer thought of as "unobtainium", he 
            said.
            The answer is carbon-nanotube-composite ribbon. Small fibers of the 
            material are set down side-by-side, then interconnected to form a 
            growing ribbon. 
            Stronger than steel
            The hurdle to date, Edwards said, has been the commercial 
            fabrication of carbon nanotubes. Both U.S. and Japanese firms, among 
            others, are ramping up production of carbon nanotubes, with tons of 
            this now exotic matter soon to be available. "That quantity of 
            material is going to be around well before five years time. It's not 
            going to take long," he said.
            Given the far stronger-than-steel ribbon of carbon nanotubes, a 
            space elevator could be up within a decade. "There's no real serious 
            stumbling block to this," Edwards explained.
            "The making of carbon nanotubes is moving very quick," said Hayam 
            Benaroya, a professor in the Department of Mechanical and Aerospace 
            Engineering at Rutgers in Piscataway, New Jersey. "We're moving from 
            the scientific stage of just developing them to actual commercial 
            entities producing them in ton-like quantities," he said.
            "Perhaps within our lifetimes we might actually see real designs of 
            skyhooks and space tethers, these kinds of things. They may be 
            feasible at reasonable cost," Benaroya said.
            Next page: Reel world high-wire act


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## Maryjane (Oct 21, 2004)

_Ok that's enough for me, enough educating for one night. Bye everyone see ya later. You to Princes Ivy _


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## Princess Ivy (Oct 21, 2004)

mj, that went straight over my head, but if you understand it, i'll trust that instead


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## Maryjane (Oct 21, 2004)

_Stick around Maryjane for a while my bestest friend Princes Ivy and I'll teach you about the real world of science which can be just as exciting as sci fi, there is a whole lot more in the bag of tricks in astrophysics and i'll try to keep it as simple as I can, like without the mathematical equations _


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## Michael (Oct 21, 2004)

Very interesting stuff, MJ. Some of this is a bit new to me. In Arthur C. Clarke's Odyssey series, he mentions that the structure would need to be built or perhaps "encased" in diamond, the only substance known that's hard enough to protect it and keep it up--and there's not enough on earth to do it. Have scientists changed their minds about this?

As far as going to Mars in 90 days, why do that when you can do it in a matter of hours with a nuclear drive?  I've mentioned this, and quoted from Carl Sagan's book Cosmos, in another thread.  The only thing stopping us from building such a ship is a treaty that bans detonation of nuclear warheads in space.


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## Maryjane (Oct 22, 2004)

_A joint international project the same they have for the space station to build the space elevator using nanotube constuction for the cable they could also build the ship for the journy to mars out of the same nanotubes which is lighter then aluminum yet dencer then plutonium and they could construct anytype propulsion system they want there would be no restricion of space and size in "free fall" orbit. Actually they are contracting proposals out for the production of nanotube cable and other components to several different manufacturers in different parts of the world right now. Let's go shop at the local nanotech shoe store for nanotube shoe laces. _


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## Michael (Oct 22, 2004)

Yes, possibly quite viable all the way.  I'll be sad if someone does not actually follow through with such a project.


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## Maryjane (Oct 22, 2004)

_It would be sad Michael, we need to move on off planet, should of never stopped since the moon landing in the 60's I think that is so incredidble that we had space travel during an era where they were using thechnology that was so primitive compared to what we have now and yet they are resuming the shuttle program only begrudgingly. With the technology we have today I find it very hard to understand why the space travel progam hasn't moved forward more. Something wrong with this picture I mean it's not just a financial thing something else is holding them back. For many years when they took pics of Mars and sent them back to earth for processing only a very small amount of info was shown to the public, now we are getting floods of none sensored data of Mars from Nasa. Is this why the interest in space flight has once more resumed?_


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## PERCON (May 26, 2005)

Give it time. Time is all they need. Recently they have shown they have concerns about sending people to distant planets, even ones like Mars which is right next to us relatively speaking, they've sent probes and robots up, in a way that's the best step forwards, it's not the only possible route but in my opinion it's the best one. Sending people to a planet where instead a lightweight probe could be sent there much faster and do practically the same job sounds safer, and better (getting repetitive now).

2007/8 will mark Virgin Atlantic's first commercial space trip out of the atmosphere and back, for anyone willing to pay for it. Virgin Atlantic have struck gold with this one, solid GOLD people! Commercial trips on a newly designed spaceship/plane out of the atmosphere for about 3-5 hours then travelling back down to Earth to land, superb I say!

"You ain't seen nothing yet!"

PERCON - "Now where did i put that hyperdrive motor?"


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## edott (Jan 9, 2006)

was wondering how many people had read Zubrin's book on going to mars. i found it very interesting.
he does his best for why we should go to mars and how to do it as cheaply and safely as possible.
if you haven't read it you should.


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## dreamwalker (Jan 10, 2006)

Oh, not another one who's gone all spirally eyed with wonder and excitement upon the mention of the hollowed "space elevator?". 

I personally think the idea is pretty regressive along with the sail. It's kinda like throwing rocks at a door instead of trying to find or make the key.

For the short term, I read up on this this plasma drive (like ion drive) which uses radio waves to heat up and ionise matter and electrostatically eject the ionised matter at much higher effecienies (amount of energy converted in to thrust) and withmuch higher impluses than standard ion drives. All though too big to be mounted on statalites or small space craft and not up to the impluse values of current rockets, it would be the best form of propultion interms of reliablity and versitity as the thrust could be varied.

Oh by the way
Nice to see you back Maryjane


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## zorcarepublic (Jan 24, 2006)

Princess Ivy said:
			
		

> sorry, but how do they stop? I mean, according to most science fiction that i've read, retros are fired to break accellaration, however that usualy takes a period of months, apparently if they break to fast they end up going staight back. my understanding of the sciences involved is very limited


Okay...

IIRC, most ideas regarding this mode of travel suggest a 'slingshot'-type manoeuvre, where the craft would attempt to slow down by using the gravity of the planet. A burst from the beam at the right time would also slow it down. Theoretically.

Im surprised they're actually considering this for inter-planetary missions, though. This was first conceived of back in the 80s, I think, where a set of lasers, set around Mercury or thereabouts, would propel a craft towards nearby stars. IIRC, the author of the book suggested a sort of laser super-highway, where lasers would be installed at all the major colonies, and a craft would ride the beam out towards a system.


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## edott (Jan 24, 2006)

everyone laughs about the space elevator and will continue to do so up until it is actually built.


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## chrispenycate (Jan 24, 2006)

edott said:
			
		

> everyone laughs about the space elevator and will continue to do so up until it is actually built.


Hey, the thing I wrote about the beanstalk/orbital tower/space elevator in "future inventions" (SFF lounge) might have been written a touch faceciously, but in no way rejects the idea; indeed, I think cutting the journey at geostationary orbit and keeping the sort of energies required for speedy interplanetary voyages well away from the planets themselves very laudible.

What I was basically critcising was the time scale- people expecting to be selling tickets in ten years, while even with maximum international cooperation, (which we're not going to get) it's closer to fifty, and at NASA speeds (zero fault technology) no-one alive today will see it finished. Remember, Clarke had his construction start in an already space based economy, we've got problems keeping one small tin can inhabitable.

One of the advantages of having your drive elsewhere from attached to you craft is that you're not strapped to a couple of hydrogen bombs worth of energy - the associated disadvantage is that a tight, directed beam as is required would make a devastating weapon in the wrong hands. As for braking (I personally hope not "breaking") while you could wait for it to swing round the planet and push back against the aquired velocity, I suggest good old fashioned atmospheric braking is the easiest - fold your light sail and deploy a parachute (NO! you can't use the same piece for both) 'Course, it'll probably take you longer slowing down than getting there - and, having left your plasma generator at home, how do you get back? (answer- you get them to send you a new one on a minimum energy orbit, which will cruise in a few years later, when you're ready to come home)


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## Admiral Ryouhei (Dec 15, 2006)

Solar Sails and Laser Propulsion Cannons
-Need another cannon at receiving point to slow/stop craft
-Send probes and super-advanced high-tech bots to mars construct a deceleration cannon and small base from where the human crew can build a larger base of operations, and eventually an orbital dock yard.

-alternatively the dock yard could be built first and then the BoO, but it's safer to build the ground base as a fallback point if something happens to the docks


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## chrispenycate (Dec 15, 2006)

Rocheworld (Forward); you build the solar sail in two, concentric pieces. Then you split it at the destination. The bigger section is accelerated more, but the reflected energy slows the smaller bit attached to the payload.
Still, this doesn't get us back again.
Probably better is to make a really big craft, which never slows down, with the actual transport craft riding piggyback. This involves a _really_ big sail, and calculating   the orbit years in advance, using the thrust to keep it on course rather than actually send it anywhere new.
Within the solar system you could probably use atmospheric braking (not, we hope, using the sail as a parachute) particularly if there were a way to furl the sail.


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## Dave (Dec 16, 2006)

Aren't the limitations Biological rather than Engineering?

I thought we couldn't survive the kind of acceleration/deceleration required to get to Mars in that short a space of time.


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## Jim Colyer (Dec 23, 2006)

I am 60.  When I was a kid, going to Mars was pure fantasy.  Now, it is technologically possible and something that will inevitably happen.


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## chrispenycate (Dec 24, 2006)

Dave said:


> Aren't the limitations Biological rather than Engineering?
> 
> I thought we couldn't survive the kind of acceleration/deceleration required to get to Mars in that short a space of time.


If you had a drive system which was optimal ( a 1 g continuous acceleration, followed by an equivalent continuous decceleration, so no free fall cruising period, and it feels as if you're standing on Earth all the time) it'd take about a couple of weeks, at worst. Unfortunately, such a drive is unlikely with any reaction-based system (which is all anybody's seriously considering at present.) The reason for the extreme physical stress is mainly energy problems. Admittedly, if we pushed the human limits and brought it down to a few days (not theoretically impossible, but practically improbable) there would be an interesting problem of particle screening at turnover; still, if we managed the propulsion, I'm sure the screening wouldn't beat us (superconducting Faraday shield perhaps?


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## Admiral Ryouhei (Feb 3, 2007)

*Spaceship Armor Carbon Nano-Buckybark*

Okay, more key points to inter-stellar travel, then


-1G-2G Drive System
Chemical>Plasma>Ion>Gravatic?

-Particle/Radiation/Moicro-Debris Shielding of crew and systems
Carbon Nano-SuperFiber Resin Shell?
~Okay, create a tiny carbon buckytube, twist it into a tight spiral, cover that nano-tube structure with another, again, twist into a spiral structured rod, finally sheath this in a connected double-layer carbon crystal nano-tube (aka diamond nano-tube), NOW, stack this "nano-fiber" segment about three layers deep around the spacecraft according to its design so that the vessel is covered in a carbon "bark"

~okay, the segments themselves, I assume, would still be quite small width-wise, length of maybe a foot at most (?) or perhaps a few inches or millimeters (again, (?)) so these will be arragned into a sort of 'plate' shape, and placed on the hull so that they overlap, making it a sort of space-age scale-mail armor.  If these nano-fiber bark armor plates were about a few feet at their largest size, then replacement would be no problem if one actually did become damaged in any way.

Now if the plate as it is already becomes deemed not good enough, then simple addin on more layer to the nano-tube segments, again a carbon-chain structure, but instead of using hexagins as the base shape, use triangles, add one or two layers of the triangle carbon structure in depth, and I think we would have something akin to Adamantium, only not designed with atmospheric reentry in mind.

In fact the adamantium could be a structure form usable with any element, so you have carbon adamantium, then tungsten or titanium adamantium.

BUT, with the prepossed oringinal structure in mind, you may be able to cut out the daimond coating and the second spiraling of the nano-tube structure.  I imagine just that by itself applyed in several layers would be sufficient enough to ward off all but the nastiest of inter-stellar debris both large and small.

Transportation is another matter, I'll leave it to you guys to figure out ^_^


Jya, Ryou


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## Gunny (Feb 6, 2007)

I would be interested in hearing arguements about trajectory correction, to increase / decrease velocity in order to avoid the unforseen obstacles that have a habit of getting in the way.

Point A to B travel in a straight line is simple enough.


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## Admiral Ryouhei (Feb 7, 2007)

and I'm still chopped liver

I think before we get to mars, we'll be colinising the earth-moon orbits will hydrponic farms and moving porcesses that polute the atmosphere into space as well, or at least the moon.

and we'll be turning the surface of earth into one big energy farm, a green one with lots of greenery coming back, and an increase in non-endangered species.

but global destruction is a long-ways off in my mind.

But to even think about populating Mars, why not populate the earth-sphere first instead, it'll settle a lot of land debates, we'll start mining the moon, and less people will laugh at the idea of an equatorial ring of space elevators/ mega-airport terminals


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## chrispenycate (Feb 8, 2007)

Admiral Ryouhei said:


> and I'm still chopped liver
> 
> I think before we get to mars, we'll be colinising the earth-moon orbits will hydrponic farms and moving porcesses that polute the atmosphere into space as well, or at least the moon.
> 
> ...



The problem with Earth orbit is lack of matter. Lifting appreciable masses out o the gravity well is ridiculously expensive, for the time being ( and go on, convince me that a space elevator could be built in less than a century, even if it were given the necessary priority. Or, if you've got a better system for getting the mass up there, append it to my "int orbit thread; I never claimed infallibility) The moon's somewhat better (and could be used as a source of raw materials for your orbital construction), but Mars is more comprehensible to a politician; it's like another country, just a bit more hostile.
And greening of the Earth could be started now, with no orbital components required. It's only economic factors, control politics and personal greed that stop it; and these factors are not going to change with space developement (neither is that enormous population excess going to reduce by emigration; they could probably breed faster in the queues leading to the elevator than they could be shipped off, and as long as it's "India's long term economic expectation is rosier than China's because they have a young, dynamic population(they've been breeding like rabbits) whereas China has an aging one (they put a sensible curb on their birthrate)"
Personally, I'd be for exploring the Asteroids - raw material just floating around loose - but they're a lot further away, and the public image of "exploration" is walking over previously unknown ground, not floating next to an untethered mountain.

And, following your "armour" suggestion; the biggest danger is from the littlest bits. High-speed collision with particles of atomoic size or less causes emission of secondary radiation, largely as gamma rays. These will be absorbed in a sufficiently dense mass (say, a water tank) but will plough straight through any lightweight structure, such as the one you're suggesting. The optimal solution is that the particles not hit the vessel at all; taking a leaf out of the Earth's book, a magnetic field could deflect them into mini van allen radiation belts, neatly sidestepping the problem except (maybe) at turnover.


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## Spartan27 (Jun 20, 2007)

chrispenycate said:


> The problem with Earth orbit is lack of matter. Lifting appreciable masses out o the gravity well is ridiculously expensive, for the time being ( and go on, convince me that a space elevator could be built in less than a century, even if it were given the necessary priority. Or, if you've got a better system for getting the mass up there, append it to my "int orbit thread; I never claimed infallibility) The moon's somewhat better (and could be used as a source of raw materials for your orbital construction), but Mars is more comprehensible to a politician; it's like another country, just a bit more hostile.
> And greening of the Earth could be started now, with no orbital components required. It's only economic factors, control politics and personal greed that stop it; and these factors are not going to change with space developement (neither is that enormous population excess going to reduce by emigration; they could probably breed faster in the queues leading to the elevator than they could be shipped off, and as long as it's "India's long term economic expectation is rosier than China's because they have a young, dynamic population(they've been breeding like rabbits) whereas China has an aging one (they put a sensible curb on their birthrate)"
> Personally, I'd be for exploring the Asteroids - raw material just floating around loose - but they're a lot further away, and the public image of "exploration" is walking over previously unknown ground, not floating next to an untethered mountain.
> 
> And, following your "armour" suggestion; the biggest danger is from the littlest bits. High-speed collision with particles of atomoic size or less causes emission of secondary radiation, largely as gamma rays. These will be absorbed in a sufficiently dense mass (say, a water tank) but will plough straight through any lightweight structure, such as the one you're suggesting. The optimal solution is that the particles not hit the vessel at all; taking a leaf out of the Earth's book, a magnetic field could deflect them into mini van allen radiation belts, neatly sidestepping the problem except (maybe) at turnover.


 
Crispy...I agree with you, to put it this way, we will need conventional and non-conventional means to pull this off (problem is most of the non-conventional thought process have not been developed due to limitations in our physics or more aptly put constraints of our physics).


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