New here, but after looking through some posts I'm glad to see others have responded on the asteroids vs. moon vs. Mars. Looking at the facts, asteroids definitely seem to provide the best place as the first location for humans to develop a space infrastructure and build up a human presence off Earth. By bringing in the small 10 meter asteroids for development of LEO to MEO it offers the best oppurtunity for the lowest cost to get humans started in space. Launches to and from the moon and Mars are still too costly with too low a return on investment to consider for serious human settlement.

The moon will always be a location for science and tourism. And Mars will definitely be the eventual place for human expansion on a very large scale, but the asteroids are where its at if we want to get some real numbers off world.

Brooks

While I agree with you that small NEAs are not to be ignored, I can't agree that the moon will be limited to science and tourism. If your only point is that the moon will never be settled in a manner analogous to the settlement of the New World, then perhaps we agree. But I definitely see the moon becoming industrialized, and being able to support itself by selling raw materials throughout cislunar space.

The big advantages the moon will have are short travel times and frequent launch windows. While it must be granted that we may need asteroids for carbon and nitrogen, the moon can provide the silicon we need for solar cells and glass, most of the metals we need, perhaps enough hydrogen to make a significant contribution, and all the oxygen we could ever want.

I also see you mention Mars as a long-term place for large-scale human expansion. Given the many advantages O'Neill outlined for orbital habitats versus planetary surfaces, I don't think it's out of the question that Mars may remain largely a backwater in comparison to the High Frontier, economically speaking. Science, certainly. Tourism, perhaps, of the limited market which would apply to a destination requiring a couple of years or more of a tourist's time. Perhaps some small number of steadfast Mars enthusiasts willing to ignore the disadvantages of planetary surfaces (and perhaps being subsidized from elsewhere). But I'm not convinced Mars will see large numbers of settlers pursing economic opportunities there.

Regards,

Mike Combs

From: spacesettlers@yahoogroups.com [mailto:spacesettlers@yahoogroups.com] On Behalf Of bhn1700
Sent: Tuesday, June 08, 2010 3:27 PM
To: spacesettlers@yahoogroups.com
Subject: [spacesettlers] New here, asteroids prefered

New here, but after looking through some posts I'm glad to see others have responded on the asteroids vs. moon vs. Mars. Looking at the facts, asteroids definitely seem to provide the best place as the first location for humans to develop a space infrastructure and build up a human presence off Earth. By bringing in the small 10 meter asteroids for development of LEO to MEO it offers the best oppurtunity for the lowest cost to get humans started in space. Launches to and from the moon and Mars are still too costly with too low a return on investment to consider for serious human settlement.

The moon will always be a location for science and tourism. And Mars will definitely be the eventual place for human expansion on a very large scale, but the asteroids are where its at if we want to get some real numbers off world.

Brooks

"Given the many advantages O'Neill outlined for orbital habitats versus planetary surfaces..."

If anybody was unsure what I was referring to: http://space.mike-combs.com/spacsetl.htm#advantages

Regards,

Mike Combs

Not to be blunt but everything the moon has the asteroids have better. Small asteroids can be brought closer then the moon, ie LEO, and with far less delta V in transporting off their surface. They contain the same silicon, metals, hydrogen and oxygen and the hydrogen and oxygen are in far greater and much more easily accessible form. Frozen H2O vs. metal oxides and sparse comet remains at the poles. Plus all the other necessary elements for life, P,S,N, etc. I do think the moon will grow as a tourist and science post to be something quite substantial, hundreds of residents even.

I see alot of potential in Mars and the question really is, beyond the science and search for life and the eventual landing of man and exploration by future government(s), what else are we going to have there? I would say the big potential is if with modest adjustment to Mars, a 'more' habitable planet is created, that settlers will come to Mars. Some forms of terraforming will not be 100's of billions in investments but 100's of millions which is within reach of very wealthy future advocates. A few directed iceteroids, mirrors in polar orbit perpendicular to the sun, black carbon on the ice caps, CFC production, etc. can be started without space race level funding and they can be measured for effect. Also the native CO2 will likely be realized into the atmosphere with added warming.

It won't be Earth like for 100's of years of course, but you could get to a much warmer and thicker atmosphere 'relatively' then now and possibly develop modest surface agriculture and useful mining enterprises deuterium and certain now rare metals on Earth. (Yes radiation, temperature, and pressure levels won't be manageable but they would be far improved from anywhere else other then Earth or in a sealed environment and would be quite modest in comparison to the sealed environment requirements elsewhere.) And the amount of space available to expand, once modest gains in the environment are made are huge relative to the investment. Obviously many things have to happen but I wouldn't say its currently a pipe dream to see it as a possible step after LEO is more maturely developed, the moon has a permanent base, and Mars has been visited and studied.

Brooks

--- In spacesettlers@yahoogroups.com, "Combs, Mike" wrote:

bhn1700 wrote:

> Not to be blunt but everything the moon has the asteroids have better.

Not true. The moon has gravity, which may be useful for some things
(and yes, eventually we'll be able to produce artificial gravity, but
not right away). More importantly it has a constant distance from
Earth, short travel time, and frequent launch windows.

> Small asteroids can be brought closer then the moon, ie LEO

That's an assertion. It's certainly true in the long run, in the same
sense as "people can travel between the stars" and "powerful bombs can
be made with antimatter," but whether we can actually do it (and do it
safely) in the near term is a very open question.

> and with far less delta V in transporting off their surface.

The delta-V for getting things off the Moon is trivial (look at the size
of the LM ascent stage, compared to the size of the Saturn V). The
delta-V for moving an asteroid into Earth orbit is decidedly NOT trivial.

> They contain the
> same silicon, metals, hydrogen and oxygen and the hydrogen and oxygen
> are in far greater and much more easily accessible form.

Another assumption, which could be wrong in several ways: most NEOs have
been well baked by the sun and may not contain more volatiles than the
Moon; and for the stuff that doesn't get baked out by the sun, there are
probably deposits of the same stuff on the Moon (from asteroid/comet
impacts if nothing else). In addition to which, we've recently
discovered large amounts of lunar water -- almost certainly falsifying
your "far greater" claim for any particular asteroid -- and it's not yet
known how easy or hard it will be to access.

Eventually NEOs (and even more eventually, main-belt asteroids) will be
valuable sources of materials. But I really don't think they're going
to be practical until we already have a thriving cislunar economy.

Best,
- Joe

--- In spacesettlers@yahoogroups.com, Joe Strout wrote:
>
> bhn1700 wrote:
>
> > Not to be blunt but everything the moon has the asteroids have better.
>
> Not true. The moon has gravity, which may be useful for some things
> (and yes, eventually we'll be able to produce artificial gravity, but
> not right away). More importantly it has a constant distance from
> Earth, short travel time, and frequent launch windows.

We are currently working in orbit with zero g, we are not currently on the moon with low g. A captured asteroid would have a constant distance, a much shorter travel time, and even more frequent (and cheaper) launch windows.

> > Small asteroids can be brought closer then the moon, ie LEO
>
> That's an assertion. It's certainly true in the long run, in the same
> sense as "people can travel between the stars" and "powerful bombs can
> be made with antimatter," but whether we can actually do it (and do it
> safely) in the near term is a very open question.

We can currently bring a spacecraft into orbit after aerobraking in the atmosphere, we can currently nudge asteroids with spacecraft as NASA has already done, combining these two currently completed off the shelf acts is hardly compareable with interstellar travel or antimatter bombs.

> > and with far less delta V in transporting off their surface.
>
> The delta-V for getting things off the Moon is trivial (look at the size
> of the LM ascent stage, compared to the size of the Saturn V). The
> delta-V for moving an asteroid into Earth orbit is decidedly NOT trivial.

The delta-V from Earth to LEO is 9.3 to 10 km/s, from the moon to LEO is roughly 5.5 km/s? What's a 10 meter asteroid, a stiff wind?Hardly trivial in comparison, and comparing all the material and fuel for Saturn Vs launch (everything goes up) with the very slimed down needs of the LM ascent (as little comes back or has been used already) is hardly compareable.

http://en.wikipedia.org/wiki/Delta-v_budget

The delta-v for shifting a 10 meter asteroid is very small, since you just need to nudge a little bit to make a much larger change later down the orbit, using aerobraking to bring your nugget into orbit will also dramatically reduce delta-v costs. (A 10 meter asteroid is the border between a meteroid and an asteroid, so fears of Armeggedon shouldn't be a problem.)

> > They contain the
> > same silicon, metals, hydrogen and oxygen and the hydrogen and oxygen
> > are in far greater and much more easily accessible form.
>
> Another assumption, which could be wrong in several ways: most NEOs have
> been well baked by the sun and may not contain more volatiles than the
> Moon; and for the stuff that doesn't get baked out by the sun, there are
> probably deposits of the same stuff on the Moon (from asteroid/comet
> impacts if nothing else). In addition to which, we've recently
> discovered large amounts of lunar water -- almost certainly falsifying
> your "far greater" claim for any particular asteroid -- and it's not yet
> known how easy or hard it will be to access.
>
> Eventually NEOs (and even more eventually, main-belt asteroids) will be
> valuable sources of materials. But I really don't think they're going
> to be practical until we already have a thriving cislunar economy.
>
> Best,
> - Joe

Current asteroids have been seen 'flaring up' showing they were actually recently deceased comets, a little shopping in the asteroid/NEO field should easily yield high volatile candidates. The current science holds that asteroids are diverse of materials from volatiles to iron/nickel, the same science says that the moon is compareably dry with potentially larger water sources at the poles. And the current science says the moon is still short of other important organics C,N,S,P, etc. that all would need to be imported. I think the case is pretty clear but I'm always open to counter evidence.

Brooks

--- In spacesettlers@yahoogroups.com, Joe Strout wrote:
>
> bhn1700 wrote:
>
> > Not to be blunt but everything the moon has the asteroids have better.
>
> Not true. The moon has gravity, which may be useful for some things
> (and yes, eventually we'll be able to produce artificial gravity, but
> not right away).

True, the moon has gravity, about 1/6 of Earth. However, this can be seen as more a liability than a benefit. To date in our extraterrestrial experience it's the ABSENCE of gravity that has produced commercial applications. And let us not kid ourselves: it's commercial profits and potential profits that will, in the final analysis, get us and keep us off the planet. Some of the fields of study yielding, or about to yield, results with a high probability of commercial applications that require an environment of microgravity include:

BIOTECHNOLOGY such as Cell Biology, Macromolecular Cell Growth, and Micro-encapsulation; COMBUSTION SCIENCE including flammability and stability limit phenomena, improved kinetics, flame structure and elementary mechanisms, combustion synthesis and catalysis of materials, fundamental benchmark data, thermophysical properties determination, process transitions, turbulence, and pattern formation, and micro-combustion-based power systems; MATERIALS SCIENCE such as Macromolecular Crystal Growth, insight into influences in the crystallization process as well as production of low-defect crystals for semiconductor and other applications, ways to control the processing of ceramics to prevent imperfections for improved optical fibers, higher reliability turbines, and bioceramics, some alloys that are difficult or impossible to produce on Earth can be made in microgravity, and manipulation of polymer bonds under microgravity conditions for potential optoelectronic and photonic applications; FLUID PHYSICS, offering a unique perspective with broad potential Earth applications in such varied areas as energy, agriculture, and manufacturing; and NANOTECHNOLOGY, including advancement of analytical devices (nano/micro system engineering, lab-on-a-chip systems or laser-optical procedures), particle coating, the production of nanoporous materials or the optimization of plasma processes in semiconductor industries, the coating of pharmaceutical drugs and surface refinement in semiconductor technology, the formation of nanoscale carbon structures by electrical arc discharge plasma synthesis and plasma etching processes for microchip production.

And we're in the infancy of these areas of inquiry- who knows where we'll go with them, the sky is literally NOT the limit any more. Now, compare there potentials with the potentials offered by Luna with it's 1/6th g environment...(?) And on the subject of 'artificial gravity', who knows if or when that might be achieved (we don't even know what gravity is, for quarks sake), but we can certainly SIMULATE it. Oh, I know, coriolis effect is a factor in a centrifugal force system. However, the greater the radius of the circle being spun, the less noticeable and disorienting the coriolis effect is to the subject experiencing it. If you're 6' tall and standing in a rotating cylinder with a radius of 20' you'll definitely be getting the dizzys, but if you're radius is 200' I doubt you'd even notice.

> More importantly it has a constant distance from
> Earth, short travel time, and frequent launch windows.
>
> > Small asteroids can be brought closer then the moon, ie LEO
>
> That's an assertion. It's certainly true in the long run, in the same
> sense as "people can travel between the stars" and "powerful bombs can
> be made with antimatter," but whether we can actually do it (and do it
> safely) in the near term is a very open question.

Herding asteroids may be an 'assertion', but you've got your time scale fantastically skewed:
"people can travel between the stars" and "powerful bombs can be made with antimatter,"
If we're not herding asteroids inside 20 years, we're probably going to be in trouble resource and energy wise, whereas your examples are possibly centuries away (aside from generation ships) and let's hope we never get around to the antimatter bombs. There are on the order of 200,000 NEOs out there to start with, tag 'em and bag'em. Use the Earth crossing asteroids as travelling habitat/spacecraft to transport men, materials and ships to the vicinity of Mars, Deimos, Phobos and the Belt and back. All of that can be accomplished in 30-40 years if we make it a priority, WHICH IT SHOULD BE. We MUST make a beginning on fixing this planet, and the only way it's gonna happen is with a large (read HUGE) influx of energy and resources from OUTSIDE the ecosystem-we've already raped our planet enough we have to start giving back!

> Eventually NEOs (and even more eventually, main-belt asteroids) will be
> valuable sources of materials. But I really don't think they're going
> to be practical until we already have a thriving cislunar economy.

I can see a thriving habitat/Earth economy easily enough, but, unless we DO herd, harvest and utilize the asteroidal resources available to us I don't see there being sufficient materials to effect any kind of 'economy' on the moon- what do you have to sell, or what potential can you offer to prospective manufacturers to set up shop there? Then there's the factor of getting those products to their markets: 1/6 g, while miniscule in comparison to Earths, will still require significant use of fuel (or a significant outlay for a linear accelerator, skyhook, etc.)- much more of an expense than would be incurred by shipping from a zero g habitat. Where do you get your building materials for your settlements (unless you utilize tunnels beneath the surface sealed somehow, or Bigelow style blowup modules or domes)? How do you live there- volatiles and water (no one knows how much ice is at the poles or if it will prove accessible, and any volatiles delivered via cometary or asteroidal strikes will necessarily be widely scattered by impact) will need to be imported though as you say there are plenty of oxides. All together, a scenario of orbiting (or free flying) habitats and asteroidal capture and harvest makes much more sense.

Victor

crookedmancreations wrote:

> > Not true. The moon has gravity, which may be useful for some things
> > (and yes, eventually we'll be able to produce artificial gravity, but
> > not right away).
>
> True, the moon has gravity, about 1/6 of Earth. However, this can be
> seen as more a liability than a benefit.

Or it can be seen as more a benefit than a liability. Depends on your
attitude, I guess. :) As I said, it may be useful for some things; and
for other things, zero-G will be useful. Eventually orbital facilities
are clearly the way to go, but we're talking about INITIAL steps here,
where our orbital facilities will not have artificial gravity.

> To date in our extraterrestrial
> experience it's the ABSENCE of gravity that has produced commercial
> applications.

That's committing two logical errors:

1. There are no commercial applications in space that care about gravity
at all (satellites would work just fine in gravity; it's their position
that matters, not the micro-G). All that hype about perfect crystals,
pharmaceuticals, etc. has not led to any actual commercialization as far
as I'm aware.

2. Even if there were such applications, you'd be confusing cause and
effect. Our "extraterrestrial" capability is limited to LEO, and we
lack artificial gravity capability (as noted above). So if we did have
any commercial applications, they would by necessity be zero-G ones.

> And let us not kid ourselves: it's commercial profits and
> potential profits that will, in the final analysis, get us and keep us
> off the planet.

Very true.

> Some of the fields of study yielding, or about to yield,
> results with a high probability of commercial applications that require
> an environment of microgravity include:
> ...

[A bunch of hypothetical stuff that has never been proven and, in my
opinion, have a low probability rather than a high one.]

> And on the subject of 'artificial gravity',
> who knows if or when that might be achieved

Indeed (though it's a matter of "when," not "if").

> Herding asteroids may be an 'assertion', but you've got your time scale
> fantastically skewed:
> "people can travel between the stars" and "powerful bombs can be made
> with antimatter,"
> If we're not herding asteroids inside 20 years, we're probably going to
> be in trouble resource and energy wise, whereas your examples are
> possibly centuries away (aside from generation ships)

Perhaps I did exaggerate to make a point, but I think you've done the
same thing; we won't be herding asteroids in 20 years. 50 years,
perhaps. Or perhaps it'll be closer to 100.

> I can see a thriving habitat/Earth economy easily enough, but, unless we
> DO herd, harvest and utilize the asteroidal resources available to us I
> don't see there being sufficient materials to effect any kind of
> 'economy' on the moon- what do you have to sell, or what potential can
> you offer to prospective manufacturers to set up shop there?

Are you kidding? Metals, volatiles (including H2 and O2), bulk mass for
radiation shielding... let's not kid ourselves, space is mostly vast
stretches of emptiness, full of plenty of solar energy (at least in the
inner solar system) but not much else. Sources of materials are
valuable, and hauling them up from Earth is dangerously close to
impractical.

> Then
> there's the factor of getting those products to their markets: 1/6 g,
> while miniscule in comparison to Earths, will still require significant
> use of fuel (or a significant outlay for a linear accelerator, skyhook,
> etc.)- much more of an expense than would be incurred by shipping from a
> zero g habitat.

If you could wave a magic wand and have a zero G habitat appear (poof!),
yes. But in that case we should wave the same wand and have the linear
accelerator appear on the Moon.

Barring such a magic wand, you have to compare the expense and
difficulty of building the mass launcher on the Moon, to building a
space habitat. The latter is probably about 100 times harder. (Indeed,
the serious folks who have studied this -- e.g., O'Neill -- quickly
concluded that you need the former to build the latter.)

> Where do you get your building materials for your
> settlements (unless you utilize tunnels beneath the surface sealed
> somehow, or Bigelow style blowup modules or domes)?

Indeed, either of those are good options. The Moon is a giant ball of
building materials; there's no shortage of good options. (Others
include building inside a lava tube, or building them out of bricks or
metal and covering them with regolith.)

> How do you live
> there- volatiles and water (no one knows how much ice is at the poles or
> if it will prove accessible, and any volatiles delivered via cometary or
> asteroidal strikes will necessarily be widely scattered by impact) will
> need to be imported though as you say there are plenty of oxides.

We know as much about lunar water as we do about asteroidal water. And
we know there's a lot of it: both concentrated at the poles, and spread
thinly but uniformly over the surface.

> All together, a scenario of orbiting (or free flying) habitats and
> asteroidal capture and harvest makes much more sense.

Long-term yes, but not initially.

Best,
- Joe

--- In spacesettlers@yahoogroups.com, Joe Strout wrote:
>
> crookedmancreations wrote:
>
> > To date in our extraterrestrial
> > experience it's the ABSENCE of gravity that has produced commercial
> > applications.
>
> That's committing two logical errors:
>
> 1. There are no commercial applications in space that care about gravity
> at all (satellites would work just fine in gravity; it's their position
> that matters, not the micro-G). All that hype about perfect crystals,
> pharmaceuticals, etc. has not led to any actual commercialization as far
> as I'm aware.
>
> 2. Even if there were such applications, you'd be confusing cause and
> effect. Our "extraterrestrial" capability is limited to LEO, and we
> lack artificial gravity capability (as noted above). So if we did have
> any commercial applications, they would by necessity be zero-G ones.

Actually you're making errors in fact and logic, first commercial companies are paying for research on ISS in zero g (an application), second space tourism includes not just great views and rocket trips but the zero g environment, third this site lists 'spinoff' commercial benefit from the space program some coming directly from zero g work. http://www.thespaceplace.com/nasa/spinoffs.html

On your second point you are the actually confusing cause and effect, we didn't pick research on ISS as a random location and then can claim what's found is linked to zero g, we purposely did research in zero g and so the applications come from the zero g research.

> > Some of the fields of study yielding, or about to yield,
> > results with a high probability of commercial applications that require
> > an environment of microgravity include:
> > ...
>
> [A bunch of hypothetical stuff that has never been proven and, in my
> opinion, have a low probability rather than a high one.]

See above link, and maybe a basis, reasoning and/or evidence for your claims of hypothetical, never proven, and low probability statements.

> > I can see a thriving habitat/Earth economy easily enough, but, unless we
> > DO herd, harvest and utilize the asteroidal resources available to us I
> > don't see there being sufficient materials to effect any kind of
> > 'economy' on the moon- what do you have to sell, or what potential can
> > you offer to prospective manufacturers to set up shop there?
>
> Are you kidding? Metals, volatiles (including H2 and O2), bulk mass for
> radiation shielding... let's not kid ourselves, space is mostly vast
> stretches of emptiness, full of plenty of solar energy (at least in the
> inner solar system) but not much else. Sources of materials are
> valuable, and hauling them up from Earth is dangerously close to
> impractical.

Again everything you just listed is in the asteroids except with even more diversity of material and even more solar energy (since a 28 day cycle leaves a lot of dark time on the moon). Also hauling materials from the moon, in reference to the previous delta V discussion, is far more expensive then the moon.

> > Then
> > there's the factor of getting those products to their markets: 1/6 g,
> > while miniscule in comparison to Earths, will still require significant
> > use of fuel (or a significant outlay for a linear accelerator, skyhook,
> > etc.)- much more of an expense than would be incurred by shipping from a
> > zero g habitat.
>
> If you could wave a magic wand and have a zero G habitat appear (poof!),
> yes. But in that case we should wave the same wand and have the linear
> accelerator appear on the Moon.
>
> Barring such a magic wand, you have to compare the expense and
> difficulty of building the mass launcher on the Moon, to building a
> space habitat. The latter is probably about 100 times harder. (Indeed,
> the serious folks who have studied this -- e.g., O'Neill -- quickly
> concluded that you need the former to build the latter.)

Um, who needs a habitat to process a 10 meter asteroid? With one or two launches ISS could have the facilities to do it. After finding a candidate and aerobraking him into orbit, work can begin.

But the moon is further out without any current infrastructure, unlike ISS, and you'd have to build the mass launcher. A very energetically costly facility that is not needed for the ISS counter part, most mass launchers call for huge energy requirements in order to accelerate mass to escape velocity.

> > How do you live
> > there- volatiles and water (no one knows how much ice is at the poles or
> > if it will prove accessible, and any volatiles delivered via cometary or
> > asteroidal strikes will necessarily be widely scattered by impact) will
> > need to be imported though as you say there are plenty of oxides.
>
> We know as much about lunar water as we do about asteroidal water. And
> we know there's a lot of it: both concentrated at the poles, and spread
> thinly but uniformly over the surface.

Probably alot of water, not alot of other volatiles though N,C,S,P and even limited current understanding is the asteroids have alot more of everything. And again in a much higher gravity well and further away.

Brooks

Victor,

Ultimately a space based civilization would use whatever is most effective for the situation.
No one doubts that asteroidscould be a resource treasure trove. Reading this group for a few years, I suspect people may have a short term difference of opinion, but the majority see the long term goal as humanity on habitats that are not located on a planet or the moon. That said, we have biases on what goals we should focus on:it could be a short term one (the moon is the most economical place to start our foray into extraterrestial resource extractions) to someone's long term view (Mars is the next home for humanity).

With that in mind, let's focus on thedifference over what some peole view asthe bestshort term step for us in space. Just like there is a split between robotics / telerobotics vs. human presence driving construction / processing, there is a preference for moon vs. asteroids.Let's covera couple of your points:

1."it's commercial profits and potential profits that will, in the final analysis, get us and keep us off the planet. Some of the fields of study yielding, or about to yield, results with a high probability of commercial applications that require an environment of microgravity"
Yes. Also, space solar power for earth (which technically is not always a gravity vs. zero-g issue)

2. "Use the Earth crossing asteroids as travelling habitat/spacecraft to transport men, materials and ships to the vicinity of Mars, Deimos, Phobos and the Belt and back. All of that can be accomplished in 30-40 years if we make it a priority"

That timetable seem very optimistic. Based on the national priorities on earth and budgets, the only way we'd get funding for this, would be after great advancements in robotics or launch costs. Does anyone see a great breakthrough in launch costs the next decade? Most likely, the pilot programs wouldbe out there now. Therefore,that agreesivetimetable would depend on getting minimal mass out of this gravity well and not worrying about how a crew returns. (focus on robotics)

As for using the asteroids for construction in earth orbit... More and morenationshave avested interests in the orbital environment. Looks like we are in for a multi-year debate on the legality and liability for asteroid capture. My opinion: we've got years before there will be an agreement allowing any government or business to capture asteroids and place them around out planet. (Al Globus wrote about asterants that carry small captured weightsthat might be acceptable.)

"I don't see there being sufficient materials to effect any kind of 'economy' on the moon- what do you have to sell, or what potential can you offer to prospective manufacturers to set up shop there?"
Yes,there are a asteroids can harbor alarge cadre of elements.

For purely practical reasons, I suspect nearterm space base resource utilization will come from the moon. Why? It is close. Telerobotics are an option (2 second delay).Shielding andstructure are the greatest contribution toa habs mass, minimizing earth launch to components that are difficult to fabricate ormaterials unavailable from the moon. This couldgreatly reduce construction costs for our nextsteps - including those withasteroids.

Amajorbenefit is potentially shorterinnovation / engineering cycles with the moon. Many have said asteroids inLEO haveeven shorter cycles, but I think in the years it will take to get significant asteroidal mass in orbit, we could have been telerobotically mining on themoon for a few decades.

Without asteroid capture, the launch / equipment engineering cycles are not better than the moon. And without asteroid capture, we need lots of advancements before we can launch an expedition and get the benefits of resource extraction.

"there's the factor of getting those products to their markets: 1/6 g... will still require significant use of fuel (or a significant outlay for a linear accelerator, skyhook, etc.)- much more of an expense than would be incurred by shipping from a zero g habitat."

Right on both points. The moon is for primary material processing,building mass,and solar power. Gettingobjects off the moon and delivered to a useful place is a challenge, but probablysafer than capturing asteroids.

On the other hand, how do we get to build the "zero g habitat" with its lower material shipping costs?

If the answer is asteroids, then who is accepting liability for herding them into orbit?The cost of a space program (if privately funded) would be bankrupted with one bad incident. Therefore, I don't such any large scale effect for many decades. Maybe not ever. Once technology is advanced enough no really large asteroid would be brought closer than a very large orbital patharound Earth. Very small asteroids 1-2 meter, maybe.

"Where do you get your building materials for your settlements (unless you utilize tunnels beneath the surface sealed somehow, or Bigelow style blowup modules or domes)?"
Someone else could go into those details. I favor robotics for the moon. In the near term it is the safer and more economical approach. Structures to be built initially would be those shelters needed for certain equipment or processes. Trying to build a large strucuture or lunar town (anything more than a construction shack for 3-4 people) would, in the near term, be a big distraction of resources from building orbital space based habs.

bhn1700 wrote:

> Actually you're making errors in fact and logic, first commercial
> companies are paying for research on ISS in zero g (an application)

Which companies? How much? I wasn't aware of this.

> second space tourism includes not just great views and rocket trips but
> the zero g environment

True, but that's an extremely limited (though admittedly nonzero) market
at this point. And at least two of the handful of space tourists has
openly expressed a desire to go to the Moon:

http://www.popularmechanics.com/science/space/4266744

So I don't think you can make a strong case that orbital tourism is
preferable to lunar tourism, except that it's available and the latter
is not (yet).

> third this site lists 'spinoff' commercial
> benefit from the space program some coming directly from zero g work.
> http://www.thespaceplace.com/nasa/spinoffs.html

Yes, but have you read this list? This is the old and tired argument
that the investment in NASA (note: not in microgravity research per se,
but NASA in general) has resulted in innovations that wouldn't have been
made otherwise. But most of those innovations would have been produced
far more cheaply if they had been invested in directly.

I'm not arguing that there aren't some valuable spin-offs, but this is a
weak argument that NASA supporters often try to take way too far.

> On your second point you are the actually confusing cause and effect, we
> didn't pick research on ISS as a random location and then can claim
> what's found is linked to zero g, we purposely did research in zero g
> and so the applications come from the zero g research.

Your logic is dumbfounding. Let's review:

1. It was claimed that "To date in our extraterrestrial experience it's
the ABSENCE of gravity that has produced commercial applications."
2. I pointed out that the only extraterrestrial commercial applications
possible would be in the absence of gravity, since we don't have any
extraterrestrial operations except in orbit.
3. You counter that... well, I can't make heads or tails of your
counter. Yes, we're doing our space research on ISS, because that's the
only place we have. Claim 1 is still a pointless tautology.

> > [A bunch of hypothetical stuff that has never been proven and, in my
> > opinion, have a low probability rather than a high one.]
>
> See above link, and maybe a basis, reasoning and/or evidence for your
> claims of hypothetical, never proven, and low probability statements.

No, if you have any one of those things that you think is NOT
hypothetical and unproven, let's see the actual non-hypothetical
products that prove them. I'm asserting that there aren't any; there's
nothing I can show to prove that, but you can easily prove the reverse.

As for the probability, that's a matter of opinion I guess, but the
original poster was claiming "results with a high probability of
commercial applications." I'm choosing to disagree.

> > > what do you have to sell, or what potential can
> > > you offer to prospective manufacturers to set up shop there?
> >
> > Are you kidding? Metals, volatiles (including H2 and O2), bulk mass for
> > radiation shielding... let's not kid ourselves, space is mostly vast
> > stretches of emptiness, full of plenty of solar energy (at least in the
> > inner solar system) but not much else. Sources of materials are
> > valuable, and hauling them up from Earth is dangerously close to
> > impractical.
>
> Again everything you just listed is in the asteroids except with even
> more diversity of material and even more solar energy (since a 28 day
> cycle leaves a lot of dark time on the moon).

Of course. I have never claimed that asteroids aren't great sources of
material. I only claim that they're not immediately USEFUL sources of
material because of the logistical difficulties their use presents.

That's the great thing about the Moon, though; everything you can find
in NEOs, you can probably find on the Moon, and it's right there 400
thousand km away all the time. See, for example:

http://www.thespacereview.com/article/205/1

So we agree that we should use NEO materials, which which have undergone
the major delta-V required to bring them into safe, stable Earth orbit.
But you're arguing that we should go out and effect that orbital
change, and I'm merely pointing out that the Moon has does this for us
already.

> Also hauling materials
> from the moon, in reference to the previous delta V discussion, is far
> more expensive then the moon.

What?

> > > Then
> > > there's the factor of getting those products to their markets: 1/6 g,
> > > while miniscule in comparison to Earths, will still require
> significant
> > > use of fuel (or a significant outlay for a linear accelerator,
> skyhook,
> > > etc.)- much more of an expense than would be incurred by shipping
> from a
> > > zero g habitat.
> >
> > Barring such a magic wand, you have to compare the expense and
> > difficulty of building the mass launcher on the Moon, to building a
> > space habitat. The latter is probably about 100 times harder.
>
> Um, who needs a habitat to process a 10 meter asteroid?

I was replying to the claim above comparing use of a linear accelerator
to "shipping from a zero g habitat."

> But the moon is further out without any current infrastructure, unlike
> ISS, and you'd have to build the mass launcher. A very energetically
> costly facility that is not needed for the ISS counter part, most mass
> launchers call for huge energy requirements in order to accelerate mass
> to escape velocity.

True, but there's plenty of energy available. Reaction mass tends to be
a bigger problem than energy. To get materials from an asteroid (or an
entire asteroid) into a useful orbit, you have to expend energy AND
reaction mass.

> Probably alot of water, not alot of other volatiles though N,C,S,P and
> even limited current understanding is the asteroids have alot more of
> everything.

Maybe. I think the main thing we've learned in the past couple of years
is that many of our assumptions about lunar resources are wrong. At
this point it seems premature to assert that the Moon doesn't have any
of those other volatiles.

> And again in a much higher gravity well and further away.

Higher gravity well, yes. Further away, no. That's the big problem
with asteroids -- they rarely come even as close as the Moon, and when
they do, they don't stick around long. Any excursion to use of them is
by necessity a very long-term project involving months or years away
from cislunar space. It's mighty cold and lonely out there, at least
for the near future.

Best,
- Joe

P.S. Thanks to all for the lively and thoughtful discussion.

Matt Gallimore wrote:

> Does anyone see a
> great breakthrough in launch costs the next decade? Most likely, the
> pilot programs would be out there now.

Agreed. I do think SpaceX is going to reduce costs by a factor of 5-10,
and once commercial service really gets into the swing of things, we
might get another factor of 2-5. But I don't see it getting a lot
cheaper than that with regular rockets.

There are more far-out concepts (lightcraft, space elevator, rotovators,
etc.) which could reduce costs more, but they're much further out than a
decade.

> As for using the asteroids for construction in earth orbit... More and
> more nations have a vested interests in the orbital environment. Looks
> like we are in for a multi-year debate on the legality and liability for
> asteroid capture. My opinion: we've got years before there will be an
> agreement allowing any government or business to capture asteroids and
> place them around out planet.

I think this is a good point. Politics and liability always get in the
way of progress (and sometimes they even keep us safe).

There may be useful stuff floating around at the Trojan points, though.
And there are almost certainly useful remnants of asteroids on the Moon.

> I favor robotics for the
> moon. In the near term it is the safer and more economical approach.
> Structures to be built initially would be those shelters needed for
> certain equipment or processes. Trying to build a large strucuture or
> lunar town (anything more than a construction shack for 3-4 people)
> would, in the near term, be a big distraction of resources from building
> orbital space based habs.

Maybe, though the more people we have living and working there, the
better they can support such big industrial projects like a space hab.

Best,
- Joe

> As for using the asteroids for construction in earth orbit... Looks like we are in for a multi-year debate on the legality and liability for asteroid capture.
OK, assuming that you're right about this, there's still absolutely nothing to stop us capturing larger asteroids, depositing them at the LaGrange points and then either processing them there or taling chips off them and using your asterants to move these more manageable (and safer) chunks into LEO or GEO for final processing and usage in orbital facilities (or on the planet assuming we come up with an economical way to get them to the ground).

***************
>1. There are no commercial applications in space that care about gravity
at all (satellites would work just fine in gravity; it's their position
that matters, not the micro-G). All that hype about perfect crystals,
pharmaceuticals, etc. has not led to any actual commercialization as far
as I'm aware.

2. Even if there were such applications, you'd be confusing cause and
effect. Our "extraterrestrial" capability is limited to LEO, and we
lack artificial gravity capability (as noted above). So if we did have
any commercial applications, they would by necessity be zero-G ones.

>[A bunch of hypothetical stuff that has never been proven and, in my
opinion, have a low probability rather than a high one.]

1. Below, find a few commercial applications. These are applications that are being done by Canada, so just imagine how much more the US, Russia and the ESA are doing.
2. Our extraterrestrial capability is NOT limited to LEO: Our military alone maintains a MINIMUM of 20 satellites in GEO and 25 in MEO (that they'll cop to), additionally there are countless other objects both military and civilian in orbits from LEO to GEO to HEO (highly eliptical orbit), over 19,000 currently. As to artificial gravity, and our lack thereof, there is nothing stopping us from simulating gravity by rotating a space structure- just because we haven't done it yet doesn't mean that we don't know how or couldn't do it easily enough.

Fluid Physics
Application: Multi-disciplinary

Canada is conducting research into fundamental sciences affected by microgravity such as fluid physics. Microgravity environments are characterized by a drastic reduction in hydrostatic pressure, sedimentation, and convection due to buoyancy. These characteristics affect virtually all processes involving fluid phases.

Gravity has a dominant effect on fluids on earth. The elimination of gravity which acts in one direction allows us to study and utilize smaller forces such as surface tension whose direction is a function of the fluid shape. Surface tension can be used to pump fluids, partition fluids, move bubbles, and even act as the container. Canada is building a float zone furnace for the production of high purity materials. Surface tension is used to replace the container walls which would contaminate the material. Understanding the influence of these forces in microgravity extends Canada's grasp on fluid physics and enhances its ability to create and control processes thus developing new products for many different applications.

Glass Manufacturing
Application: Fibre Optic Cables

Canada is conducting research in glass manufacturing in microgravity. Fluorozirconate is a material used to make fibre optics. In the manufacturing process on earth some crystal formation occurs, and crystals reduce the ability of glass to transmit light. The manufacture of fluorozirconate glasses in microgravity reduces crystal formation. Today fibre optic cables require repeaters or boosters every five to ten kilometres. Researching glass formation in microgravity will assist Canada to develop fibre optic cables able to transmit a signal without repeaters across the Atlantic Ocean, a distance of 3200 km. This will enhance and extend Canada's role as a preeminent nation in global telecommunications.

Crystal Growth

Application: Electro-optical and Photonic Equipment

Gravitational effects such as convection currents, sedimentation and hydrostatic pressure variation reduce the uniformity of crystals grown in a gravity environment. Also, uncontrolled nucleation at the container walls leads to imperfections in crystal structure as well as the presence of impurities in the crystal lattice. These factors reduce crystal size and purity, which are critical parameters in crystal performance.

Canada is researching crystal growth in microgravity where convection, sedimentation and hydrostatic pressure variation are substantially reduced. The resulting crystals show significant improvements in crystal structure, purity and uniformity. In addition, containerless processing will reduce contaminant presence in crystal lattices, further improving crystal purity and process yields. Crystals manufactured in microgravity will be used to create high precision, high power lasers, microwave broadcast devices, more sensitive heat sensors, and higher resolution video cameras.

Ceramics

Application: High-Temperature Applications

The role of microgravity in improving ceramics is similar to that in improving crystals. Containerless processing of ceramics will reduce contaminants, and both uniformity and purity will be improved by using a microgravity environment.

Advanced ceramics created by Canada in microgravity exhibit desirable mechanical properties such as creep stability, impact resistance and strength. Furthermore, they maintain these properties at high temperatures, giving them a significant advantage over metal alternatives. These new ceramics will be used to replace metals where high temperatures limit the usefulness of metals. For instance, advanced ceramics can be used to coat the blades in hydroelectric turbines. The blades will be stronger and last longer, resulting in fewer breakdowns.

Biotechnology - Protein Crystallization
Application: New Treatments For Human And Plant Disease

Canada is conducting research to determine the structure of proteins in living things. The process or research methodology is called protein crystallization. Proteins which exist in liquid solutions are first crystallized and then analyzed with X-ray diffraction to determine the protein structure. Proteins crystallized in microgravity are often larger and of higher quality than crystals grown on earth, facilitating structure determination. Knowledge of the protein structure can be used to design more effective drugs to combat disease in both plants and humans. Protein crystallization has been used to determine the structure of viral shells, which protect a virus from the body's natural immune system. Using results from protein crystallization, Canadian researchers will be able to develop drugs to break down the shell and permit the body to attack and destroy the virus.

Materials
Application: Metals and Alloys

Alloys are made by mixing two immiscible liquid metals together and letting them solidify. If a mixture of oil and water is shaken, the oil droplets spread through the water. Freezing the mixture simulates an alloy - droplets of one material distributed in a matrix of another. The strength of an alloy increases as droplets become smaller and as droplet distribution becomes more uniform.

Gravity affects both of these parameters. Droplets are usually of a different density than the matrix, so sedimentation causes them to settle, reducing the uniformity of droplet distribution as the mixture hardens. Droplets of different weight settle at different rates, quicker droplets merging with slower droplets to create larger ones. This is agglomeration. Sedimentation is absent in microgravity so droplets don't collide and agglomerate, resulting in smaller droplets, uniform distribution and therefore stronger alloys. Canada's microgravity alloying research will advance our understanding of metal behaviour and enhance alloy production on earth.

http://www.asc-csa.gc.ca/eng/educators/resources/microgravity/research.asp#tphp

****************

In respect to resources on the moon:

>Are you kidding? Metals, volatiles (including H2 and O2), bulk mass for
radiation shielding... let's not kid ourselves, space is mostly vast
stretches of emptiness, full of plenty of solar energy (at least in the
inner solar system) but not much else. Sources of materials are
valuable, and hauling them up from Earth is dangerously close to
impractical.

There is a notable LACK of one of the primary volatiles-Carbon- on the moon; While there is quite a bit of iron on the moon, it's widely distributed in the regolith. Processing the regolith and releasing the iron in a usable form is NOT going to be an easy task- while some processes have been worked out for processing metals in zero g, 1/6 g will present all kinds of problems ranging from melting the iron particles out of the regolith in such a way as to have them precipitate out with few impurities to the fact that 1/6g smelting/cooling will rersult in deformed crystaline matrix formation and variable precipitation layers in the alloys. Much easier to capture metal asteroids and process already purified metals in zero g. Sources of materials are valuable, and hauling them up from the surface of the moon is dangerously close to impractical.

****************

>If you could wave a magic wand and have a zero G habitat appear (poof!),
yes. But in that case we should wave the same wand and have the linear
accelerator appear on the Moon.

Barring such a magic wand, you have to compare the expense and
difficulty of building the mass launcher on the Moon, to building a
space habitat. The latter is probably about 100 times harder. (Indeed,
the serious folks who have studied this -- e.g., O'Neill -- quickly
concluded that you need the former to build the latter.)

Ah, but we ALREADY have zero g facilities (ISS and Bigelows' Genesis already in space), albeit not yet full habitats. Bigelow could probably have a habitat up and in orbit, ready to begin processing as soon as we could realistically capture an asteroid for them to work on given that they received interest and funding equal to 1 shuttle launch, whereas, even though Bigelow also has plans for lunar base/construction shack modules using the Genesis format, just getting them to the moon and set up would be much more expensive and that doesn't begin to attack the problems attendant on processing lunar materials. I mean we're looking at significant goal oriented steps that we can take in the SHORT RUN, right? Granted, down the road, once we have processing going on the moon and a delivery system in place to get it back off the moon we can then begin building big O'Niell haqbitats utilizing regolith for shielding, but in the short run we need to get industry going in space- start with small construction shack modules like Genesis to process small asteroids or fragments of larger ones kept at L-points while personnel are housed in Genesis type modules of larger scale that can be rotated to provide crew and industry workers with gravity that will enable long term stays in orbit without deterioration.

****************

The High Frontier

These lyrics are by John Stewart and T. A. Heppenheimer to replace the original words of the song "The New Frontier," written by John Stewart of the Kingston Trio in 1962 to honor President John F. Kennedy.

Some to the rivers and some to the sea,
Some to the soil that our fathers made free,
Then on to the stars in the heavens for to see,
This is the High Frontier, this is the High Frontier.

Let the word go forth, from this day on
A new age of mankind has begun.
Hope will grow for the human race!
We're building a colony deep in space!
This is the High Frontier, this is the High Frontier.

Let us begin, for it shall take long,
Let everyone sing a freedom song.
Not for ourselves that we take this stand,
Now it's the world and the future of Man.
This is the High Frontier, this is the High Frontier.

The day will come, it's going to be,
A day that we will someday see
When all mankind is reaching out
Without a limit, without a doubt!
This is the High Frontier!

On 12.06.2010 06:53, Victor Smith wrote:
> > As for using the asteroids for construction in earth orbit... Looks
> like we are in for a multi-year debate on the legality and liability for
> asteroid capture.
> OK, assuming that you're right about this, there's still absolutely
> nothing to stop us capturing larger asteroids, depositing them at the
> LaGrange points and then either processing them there or taling chips
> off them and using your asterants to move these more manageable (and
> safer) chunks into LEO or GEO for final processing and usage in orbital
> facilities (or on the planet assuming we come up with an economical way
> to get them to the ground).

There would be another way also. To use solar-sail/-solar-electric
propulsion motherships with a central docking and payload station which
could carry several daughter units like asteroid landers which are
collecting asteroidal materials.

The mothership would return those daughters with their collected
materials, say about 10 tons per mission back to the ISS for examination
and research.

Later those materials could be pre- processed at the NEA, so that only
the valuable materials would have to be transported back to LEO or Earth.

The point is, that for that kind of exploration light spacecraft
(mothership and daughter units) can be used by remote control. Those
spacecraft, using ion thrusters would not be able to land on the moon,
but to land on asteroids and return some tons of material with each
mission. Having more of those lightweight motherships would ensure a
steady stream of materials.

Best wishes

Frank

> > As for using the asteroids for construction in earth orbit... Looks like we are in for a multi-year debate on the legality and liability for asteroid capture.

> OK, assuming that you're right about this, there's still absolutely nothing to stop us capturing larger asteroids, depositing them at the LaGrange points and then either processing them there or taling chips off them and using your asterants to move these more manageable (and safer) chunks into LEO or GEO for final processing and usage in orbital facilities (or on the planet assuming we come up with an economical way to get them to the ground).

A few issues with parking larger asteroids in L4 or L5. Moving a bigger asteroid toward Earth will take more mass/energy then smaller meteroids, though admittedly this will not be a major issue. Slowing down the asteroid for capture will be a major problem though. Most asteroids can be moved by parking a spacecraft off thier surface and 'nudging' them with gravity into the direction that you want over time. This allows a very small nudge early in their orbit to make a big difference later. Well, when you 'arrive' at L4 you'll traveling at a high speed relative to the Earth/moon system and gravity tugs will not be enough to slow you down in time. Directly landing on the surface is problematic because it is estimated that the vast majority of asteroids, except the very small and very large ones are 'rubble piles.' An option is to aerobrake the asteroid using the Earth's atmosphere, but that gets you back to the question many will ask, why are you aiming a 200 meter asteroid at the Earth's upper atmosphere?! :)

Another issue is L4 and L5 points may not be stable locations, the pertubations of other planets, and more so the sun, are enough to make adjustments to an orbit necessary. A solution is using a kind of looping orbit, kind of like a kidney beans orbit within the L4,L5 zone, this is expected to create a much more stable situation. Getting the asteroid into that new orbit will be interesting, though not likely a major obstacle, if you've already gotten an asteroid captured in L4,L5 this would be minor in comparison.

Brooks

Bodies in space have very high velocities. The orbital velocity of Earth
around the Sun is 29.8 Km/s. Capture of asteroids becomes economical, in
comparison with operations from the moon only if the operation can be
completed with a delta v budget of 2.4 Km/s (which is the escape velocity
from the Moon).

Regards
Selvaraj

On 9 June 2010 01:57, bhn1700 wrote:

As for stopping and capturing the asteroid in an L point, or multi-L, I would expect to use your initial delivery burn to start the rock on an intercept course designed to utilize a gravity assist from the moon to slow it upon arrival. This way, you shed most of the velocity before locking onto a much slowed rock with a tug for its final delivery into whichever parking orbit you've determined for it.

From: bhn1700
Sent: Monday, June 14, 2010 3:10 PM
To: spacesettlers@yahoogroups.com
Subject: [spacesettlers] Re: New here, asteroids prefered

> > As for using the asteroids for construction in earth orbit... Looks like we are in for a multi-year debate on the legality and liability for asteroid capture.

> OK, assuming that you're right about this, there's still absolutely nothing to stop us capturing larger asteroids, depositing them at the LaGrange points and then either processing them there or taling chips off them and using your asterants to move these more manageable (and safer) chunks into LEO or GEO for final processing and usage in orbital facilities (or on the planet assuming we come up with an economical way to get them to the ground).

A few issues with parking larger asteroids in L4 or L5. Moving a bigger asteroid toward Earth will take more mass/energy then smaller meteroids, though admittedly this will not be a major issue. Slowing down the asteroid for capture will be a major problem though. Most asteroids can be moved by parking a spacecraft off thier surface and 'nudging' them with gravity into the direction that you want over time. This allows a very small nudge early in their orbit to make a big difference later. Well, when you 'arrive' at L4 you'll traveling at a high speed relative to the Earth/moon system and gravity tugs will not be enough to slow you down in time. Directly landing on the surface is problematic because it is estimated that the vast majority of asteroids, except the very small and very large ones are 'rubble piles.' An option is to aerobrake the asteroid using the Earth's atmosphere, but that gets you back to the question many will ask, why are you aiming a 200 meter asteroid at the Earth's upper atmosphere?! :)

Another issue is L4 and L5 points may not be stable locations, the pertubations of other planets, and more so the sun, are enough to make adjustments to an orbit necessary. A solution is using a kind of looping orbit, kind of like a kidney beans orbit within the L4,L5 zone, this is expected to create a much more stable situation. Getting the asteroid into that new orbit will be interesting, though not likely a major obstacle, if you've already gotten an asteroid captured in L4,L5 this would be minor in comparison.

Brooks

From: Victor Smith

> As for stopping and capturing the asteroid in an L point, or multi-L, I would expect
> to use your initial delivery burn to start the rock on an intercept course designed to
> utilize a gravity assist from the moon to slow it upon arrival. This way, you shed most
> of the velocity before locking onto a much slowed rock with a tug for its final delivery
> into whichever parking orbit you've determined for it.

Brian O'Leary published on this subject back on the 70's. He recommended gravity assist maneuvers past both the Moon and Venus.

Regards,

Mike Combs

If the destination is LEO, where most everything is happening, it is closer to 2.7 km/s. From most asteroids considered, delta v is negligible off the surface. To ship resources to LEO I'm sure it would be more but unlikely more then the moon. And if we capture very small nearby NEOs that are whizzing by the Earth anyway, the delta v is even lower.

Brooks

--- In spacesettlers@yahoogroups.com, sraj wrote:

2. "Use the Earth crossing asteroids as travelling habitat/spacecraft to transport men, materials and ships to the vicinity of Mars, Deimos, Phobos and the Belt and back. All of that can be accomplished in 30-40 years if we make it a priority"

That timetable seem very optimistic. Based on the national priorities on earth and budgets, the only way we'd get funding for this, would be after great advancements in robotics or launch costs. Does anyone see a great breakthrough in launch costs the next decade? Most likely, the pilot programs would be out there now. Therefore, that agreesive timetable would depend on getting minimal mass out of this gravity well and not worrying about how a crew returns. (focus on robotics)

National priorities and funding become less and less of an obstacle as private sector gains more and more experience and infrastructure in space. SSP is an energy resource too important to the planet to be long put off, and there'll be too much money to be made in nexgen power for private enterprise to hesitate long once ssto makes achieving orbit economical and something that can be done routinely and often. Private aerospace companies in US are too close to accomplishing too many diverse ssto configurations to be able to judge which one or more of them will emerge as the eventual mainstay, but with a new influx of money and finally some official acknowledgement progress can not fail to accelerate. Whether it's Bigelow or some other company that gets serious about establishing manned installations on a larger scale to include industrial capability to begin producing and deploying powersats, someone will, and probably sooner than later. Some or all of the necessary materials for these development will come from terrestrial mining/processing and then be shipped to orbit. We should, to the best of our ability, minimize this for the simple reasons that it's the most costly in terms of monetary and lift charges and in terms of damage to the environment in producing/processing. Personally, I hope that someone gets the idea soon to mount a salvage company enterprise in leo cleaning up and recycling all the trash in orbit. Following that, go in two ways, start sweeping up the thousands of earth crossing asteroids and establish some kind of habitat on the moon to look into methods of processing whatever can be gotten there, though it won't be easy. I can see all this happening in a decade and a half, after all, we went to the moon, landed men and brought them back in five years less than that. And, that was 40 years ago, built on a miniscule data base compared to ours and entailed virtually no financial incentive, compared to trillions in potential profits. Unfortunately (or fortunately for those of us that believe in human presence in space) I see little application for robotics in this progression save for lunar development and possibly drone rock hunters/tugs. With NASA putting its $'s and dreams into extraterrestrial vehicles, new ssto's from private sector, flourishing industry in orbit and an ever increasing need for resources on earth and in orbit, I see nothing unrealistic or overly optimistic in my original timetable: "Use the Earth crossing asteroids as travelling habitat/spacecraft to transport men, materials and ships to the vicinity of Mars, Deimos, Phobos and the Belt and back. All of that can be accomplished in 30-40 years if we make it a priority." Granted, adapting an asteroid to use as a permanent spacecraft/base/settlement, together with orbital modification may be at the edge of do-ability in that time frame, but, given the fact that it would be tantamount to having an elevator from Earth to Mars and the asteroids, it would be worthwhile to make it a priority.

Brooks,

I am not too sure you are correct. Have a look at the orbit of this
asteroid:

http://www.jpl.nasa.gov/news/news.cfm?release=2010-115

Assume that its orbit has to be corrected by just 10 degrees, and it has a
velocity of 20 Km / s

You will need to apply a lateral delta v of 20 tan 10degrees to affect this
correction.

That works out to 3.5 Km/s

I think we will need to work out a particular case to gain confidence that
it is possible to capture an asteroid with very low expenditure of delta v.
Also, dynamic braking can be done using the atmosphere of the Earth, since
the Moon has no atmosphere, it cannot be used for this purpose.

(Those of you who may not be aware, google search engine seem to be better
than excel for doing calculations. Just enter tan 10 degrees *20 into your
search query and hit 'Enter').

Regards
Selvaraj

On 17 June 2010 00:43, bhn1700 wrote:

There will be countless candidates of meteroids/asteroids 5 - 10 meters across that come very close to Earth now. Adjusting their trajectories with the mass of a small spacecraft by meeting and 'parking' over and in the direction you want the object to go should take very little energy.

p = MV = Ft

p momentum
M mass
V velocity
F force
t time

Since we are picking from a very small class of asteroid, 10 meter, 2900 tons, we have kept M very low. Since we pick the asteroid with a favorable orbital path (just hitting or just missing Earth) we can keep the V very low. Since we are picking the asteroid we can also have more t time on our hands to adjust its orbit. Without doing the math it would seem to be a very cheap option, energetically, to grab an asteroid of our choice and put it into an aerobraking trajectory. And then bring it to ISS and begin study and processing of its material.

I can't see how the same mass leaving the moon to ISS would be lower in energy costs, delta v, then minor adjustments to the same mass already on course for Earth.

Brooks

--- In spacesettlers@yahoogroups.com, sraj wrote:

I am pretty much all about dealing with radiation first of all, then propulsion. NASA is making some plastic hull material that mitigates GCR. I think this is pretty important stuff. If you have an out plastic hull and an inner and fill the void up with moon water then for the first time there may be a way to actually go out there and not die of cancer. Of course to push all those hundreds of tons of water (minimum) you will need nuclear propulsion and the only viable nuclear propulsion system is Nuclear Pulse Propulsion (bombs).

--- On Fri, 6/18/10, brooksn wrote:

From: brooksn
Subject: [spacesettlers] Re: New here, asteroids prefered
To: spacesettlers@yahoogroups.com
Date: Friday, June 18, 2010, 9:23 AM

There will be countless candidates of meteroids/asteroids 5 - 10 meters across that come very close to Earth now. Adjusting their trajectories with the mass of a small spacecraft by meeting and 'parking' over and in the direction you want the object to go should take very little energy.

p = MV = Ft

p momentum

M mass

V velocity

F force

t time

Since we are picking from a very small class of asteroid, 10 meter, 2900 tons, we have kept M very low. Since we pick the asteroid with a favorable orbital path (just hitting or just missing Earth) we can keep the V very low. Since we are picking the asteroid we can also have more t time on our hands to adjust its orbit. Without doing the math it would seem to be a very cheap option, energetically, to grab an asteroid of our choice and put it into an aerobraking trajectory. And then bring it to ISS and begin study and processing of its material.

I can't see how the same mass leaving the moon to ISS would be lower in energy costs, delta v, then minor adjustments to the same mass already on course for Earth.

Brooks

--- In spacesettlers@yahoogroups.com, sraj wrote:

1. NOT aerobraking- you're right...no atmosphere on the moon- instead, the reverse of a gravity slingshot, utilizing a swing by the moon (or Venus, the sun or both plus Luna for far out or very fast rocks) to reduce or augment delta v so as to modify an asteroids orbit so that it makes rendezvous with either a L-point or a position in Earth orbit at a nice safe speed to be met and towed to processing facilities. BTW, lunar orbit would suffice for processing facilities as well. I don't know that I would promote aerobraking anything past meteoric size in the Earths atmosphere due to safety considerations...luckily, though, it's not necessary.

2. Nuclear Pulse is NOT the only viable nuke propulsion system:

Begun in 1955, by the USAF, and then taken over in 1958 by NASA at that agencys' creation, NERVA (Nuclear Engine for Rocket Vehicle Application) was the expected rocket motor under development for the planned manned Mars mission then scheduled for launch in November 1981 with a manned landing in August 1982. In the late 1960s and early 1970s the Nixon administration drastically cut funding for NASA and NERVA. Eventually the NERVA/Rover program lost its altogether, and was terminated on January 5, 1973. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests at the Nuclear Rocket Development Station at the AEC's Nevada test site in Jackass Flats. These included the KIWI, PHOEBUS, PEEWEE-1 AND NUCLEAR FURNACE 1 test series on the rover reactor systems and the NRX-A2, A3, EST, A5, A6 and XE-PRIME series on the NERVA engine.

The NERVA program started out with the following objectives:
multi-mission capability
man-rated
based on full-flow topping
minimum chamber temperature of 2360 K and a minimum chamber pressure of 450 psia
minimum 75,000 lbf thrust
endurance of 600 minutes and up to 60 cycles
capable of 85,000 lbf and 500 psia transients
incorporating adequate shielding for manned operations
storable for 5 years on the ground, 6 months on pad, and 3 years in space
transportable by land, sea, and air

To meet these objectives, NERVA consisted of two reactor projects: the Nuclear Reactor eXperiment (NRX) and the eXperimental flight Engine Prototype (XE-Prime).

During its lifetime the NERVA/Rover programs accomplished the following records:
highest power: 4500 megawatts thermal power
5,500F exhaust temperature
250,000 pounds thrust
850 sec. of specific impulse
90 min. of burn time
thrust to weight ratios of 3 to 4

By the time the NERVA program was terminated, the NERVA-2 had been designed that would have met all of the program's objectives. Two of these engines would have been fitted to a NERVA stage capable of powering a manned interplanetary spacecraft. The final NERVA Alpha Flight Engine reference configuration, as documented at the end of its development, was an engine that could be launched together with its stage and a payload in a single shuttle launch. The final engine planned for the Mars mission would have been a scaled up version of this design and the Mars ship would have incorporated a pair of them.

http://www.astronautix.com/engines/nerva.htm
http://www.daviddarling.info/encyclopedia/N/NERVA.html
http://en.wikipedia.org/wiki/NERVA
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910017902_1991017902.pdf
http://www.scribd.com/doc/29472345/How-the-NERVA-Rocket-Engine-Works

From: Gary Church
Sent: Friday, June 18, 2010 8:01 PM
To: spacesettlers@yahoogroups.com
Subject: Re: [spacesettlers] Re: New here, asteroids prefered

I am pretty much all about dealing with radiation first of all, then propulsion. NASA is making some plastic hull material that mitigates GCR. I think this is pretty important stuff. If you have an out plastic hull and an inner and fill the void up with moon water then for the first time there may be a way to actually go out there and not die of cancer. Of course to push all those hundreds of tons of water (minimum) you will need nuclear propulsion and the only viable nuclear propulsion system is Nuclear Pulse Propulsion (bombs).

--- On Fri, 6/18/10, brooksn wrote:

From: brooksn
Subject: [spacesettlers] Re: New here, asteroids prefered
To: spacesettlers@yahoogroups.com
Date: Friday, June 18, 2010, 9:23 AM

There will be countless candidates of meteroids/asteroids 5 - 10 meters across that come very close to Earth now. Adjusting their trajectories with the mass of a small spacecraft by meeting and 'parking' over and in the direction you want the object to go should take very little energy.

p = MV = Ft

p momentum

M mass

V velocity

F force

t time

Since we are picking from a very small class of asteroid, 10 meter, 2900 tons, we have kept M very low. Since we pick the asteroid with a favorable orbital path (just hitting or just missing Earth) we can keep the V very low. Since we are picking the asteroid we can also have more t time on our hands to adjust its orbit. Without doing the math it would seem to be a very cheap option, energetically, to grab an asteroid of our choice and put it into an aerobraking trajectory. And then bring it to ISS and begin study and processing of its material.

I can't see how the same mass leaving the moon to ISS would be lower in energy costs, delta v, then minor adjustments to the same mass already on course for Earth.

Brooks

--- In spacesettlers@yahoogroups.com, sraj wrote:

NERVA has an ISP of 850- from a reaction one million times more powerful than chemical fuel. Like using a napalm airstrike to light a cigarette. The problem with any nuclear rocket is containment- it is hard enough to keep a chemical rocket from melting. Stan Ulam correctly deduced that a fast fission device- a bomb- would be the most effective propulsion system for spacecraft. That was in 1945 shortly after the first one was lit off. It is still the only system that does not waste almost the entire amount of energy being produced. ISP for a Nuclear Pulse Propulsion system would be in the thousands and most probably in the tens of thousands.

--- On Fri, 6/18/10, Victor Smith wrote:

From: Victor Smith
Subject: Re: [spacesettlers] Re: New here, asteroids prefered
To: spacesettlers@yahoogroups.com
Date: Friday, June 18, 2010, 9:53 PM

1. NOT aerobraking- you're right...no atmosphere on the moon- instead, the reverse of a gravity slingshot, utilizing a swing by the moon (or Venus, the sun or both plus Luna for far out or very fast rocks) to reduce or augment delta v so as to modify an asteroids orbit so that it makes rendezvous with either a L-point or a position in Earth orbit at a nice safe speed to be met and towed to processing facilities. BTW, lunar orbit would suffice for processing facilities as well. I don't know that I would promote aerobraking anything past meteoric size in the Earths atmosphere due to safety considerations...luckily, though, it's not necessary.

2. Nuclear Pulse is NOT the only viable nuke propulsion system:

Begun in 1955, by the USAF, and then taken over in 1958 by NASA at that agencys' creation, NERVA (Nuclear Engine for Rocket Vehicle Application) was the expected rocket motor under development for the planned manned Mars mission then scheduled for launch in November 1981 with a manned landing in August 1982. In the late 1960s and early 1970s the Nixon administration drastically cut funding for NASA and NERVA. Eventually the NERVA/Rover program lost its altogether, and was terminated on January 5, 1973. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests at the Nuclear Rocket Development Station at the AEC's Nevada test site in Jackass Flats. These included the KIWI, PHOEBUS, PEEWEE-1 AND NUCLEAR FURNACE 1 test series on the rover reactor systems and the NRX-A2, A3, EST, A5, A6 and XE-PRIME series on the NERVA engine.

The NERVA program started out with the following objectives:

multi-mission capability

man-rated

based on full-flow topping

minimum chamber temperature of 2360 K and a minimum chamber pressure of 450 psia

minimum 75,000 lbf thrust

endurance of 600 minutes and up to 60 cycles

capable of 85,000 lbf and 500 psia transients

incorporating adequate shielding for manned operations

storable for 5 years on the ground, 6 months on pad, and 3 years in space

transportable by land, sea, and air

To meet these objectives, NERVA consisted of two reactor projects: the Nuclear Reactor eXperiment (NRX) and the eXperimental flight Engine Prototype (XE-Prime).

During its lifetime the NERVA/Rover programs accomplished the following records:

highest power: 4500 megawatts thermal power

5,500F exhaust temperature

250,000 pounds thrust

850 sec. of specific impulse

90 min. of burn time

thrust to weight ratios of 3 to 4

By the time the NERVA program was terminated, the NERVA-2 had been designed that would have met all of the program's objectives. Two of these engines would have been fitted to a NERVA stage capable of powering a manned interplanetary spacecraft. The final NERVA Alpha Flight Engine reference configuration, as documented at the end of its development, was an engine that could be launched together with its stage and a payload in a single shuttle launch. The final engine planned for the Mars mission would have been a scaled up version of this design and the Mars ship would have incorporated a pair of them.

http://www.astronautix.com/engines/nerva.htm

http://www.daviddarling.info/encyclopedia/N/NERVA.html

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

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910017902_1991017902.pdf

http://www.scribd.com/doc/29472345/How-the-NERVA-Rocket-Engine-Works

From: Gary Church

Sent: Friday, June 18, 2010 8:01 PM

To: spacesettlers@yahoogroups.com

Subject: Re: [spacesettlers] Re: New here, asteroids prefered

I am pretty much all about dealing with radiation first of all, then propulsion. NASA is making some plastic hull material that mitigates GCR. I think this is pretty important stuff. If you have an out plastic hull and an inner and fill the void up with moon water then for the first time there may be a way to actually go out there and not die of cancer. Of course to push all those hundreds of tons of water (minimum) you will need nuclear propulsion and the only viable nuclear propulsion system is Nuclear Pulse Propulsion (bombs).

--- On Fri, 6/18/10, brooksn wrote:

From: brooksn

Subject: [spacesettlers] Re: New here, asteroids prefered

To: spacesettlers@yahoogroups.com

Date: Friday, June 18, 2010, 9:23 AM

There will be countless candidates of meteroids/asteroids 5 - 10 meters across that come very close to Earth now. Adjusting their trajectories with the mass of a small spacecraft by meeting and 'parking' over and in the direction you want the object to go should take very little energy.

p = MV = Ft

p momentum

M mass

V velocity

F force

t time

Since we are picking from a very small class of asteroid, 10 meter, 2900 tons, we have kept M very low. Since we pick the asteroid with a favorable orbital path (just hitting or just missing Earth) we can keep the V very low. Since we are picking the asteroid we can also have more t time on our hands to adjust its orbit. Without doing the math it would seem to be a very cheap option, energetically, to grab an asteroid of our choice and put it into an aerobraking trajectory. And then bring it to ISS and begin study and processing of its material.

I can't see how the same mass leaving the moon to ISS would be lower in energy costs, delta v, then minor adjustments to the same mass already on course for Earth.

Brooks

--- In spacesettlers@yahoogroups.com, sraj wrote: