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).

***************
>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!