Please go to the NSS website and look at

nss ==> settlement ==> journal ==> Curreri and Detweiler

Also, SSI ==> 2010 conference – space manufacturing 14 ==>

archives of space manufacturing 14 ==>

Habitat Size Optimization of the O’Neill – Glaser Economic Model for Space Solar Satellite Production

You may be right but how much experimenting have we done in space? Much of what we know about what we can manufacture in space is based on earthbound hypothesis not actual experiment. I don’t like assuming it can’t be done until we actually do the experiments.

My point was that we’re not going anywhere in space until we find something up there that’s profitable enough to let us start building an infrastructure. Once we get an infrastructure, we can make more things profitable.

If human kind only looked at what we can do now and didn’t experiment, we wouldn’t have any technology.

Transparent aluminum is a star trek reference, which you probably got.

Physicist Mike Combs (of the Space Studies Institute) said studies of power sat costing indicated the break point at 30 power sats, as in, if all we ever built were 30, it would be cheaper to just launch them from earth. Beyond 30, scale increases would allow a reduction of per unit construction costs by building them in space from lunar material.

Returning refined metals and such from orbit to earth is easy, since it’s all downhill. We just add nitrogen bubbles to the molten metal, making the foamed metal lighter than water, so after dumping them in the sea, the pieces that survive re-entry will float and are easily retrieved.

Transparent aluminum is just clear sapphire and we can make that here. Perfect crystals are easier to make in free fall but near perfect is what we already have.

Energy is about the only thing that is truly cost effective but it only works if we’re willing to dedicate a significant percentage of the worlds GDP to creating the infrastructure.

…catch 22…

Gary 7

Zero G manufacturing.

What if you could make a room temperature superconductive material in zero G? Or a cure for cancer or baldness or many types of colds? Or the newest microchip 100 times faster than any made on earth? Transparent aluminum? What’s produced must be expensive and light to make it profitable to ship raw materials from earth and finished products back.

Who predicted tobacco when the new world was settled? (Hopefully the product we find won’t slowly kill us.) We don’t know what we can make ,yet.

Once we’ve found a few profitable products and built up an infrastructure in neo, it would be easier to take on bigger projects like power, especially if we can divert close earth objects into lunar orbit for raw materials.

Gerard O’Neilles studies started 40 years ago and what his team came up with as an economic rationale was simply energy. Solar energy at earths surface, at high noon, on a good, clear day, is about 350 watts/m^2 and that’s for only a few hrs/day. In space, at earths orbit, it’s about 1350 watts/m^2, available 24/7/365. Generation of electricity on earth is currently a multi trillion dollar/yr business. Transmitting that much energy to earth via “radio waves” is relatively easy. Building the power sats from lunar raw materials is doable but the infrastructure costs are in the multi hundred billion range. If power sats are the economic rationale, at least you have a POTENTIAL economic return but, who but a government(or several, working together over a 20 year span) would be able to spend such sums? THAT’S the real question.

Gary 7

1) A a transshipment point. Everything gets shipped from earth to one big rotating station and then shipped from there by a true space ship. Some would be small robot controlled ships to ship small packages. That way you have every shuttle up full and you have a central point to store vital spare parts. Need a 1 kg part. Have it shipped to the habitat. Put it in a small automated space ship. Launch it towards the destination. It fly’s itself there. Then send the small ship to the next place that needs it. All of this happens in earths orbit at first.

2) A place to acclimate to zero G. The apparent gravity would change from floor to floor.
Some people take a while to get used to zero g. Going from .5, to .3 to .1 to .01 to 0g might be easier.

3) You could rotate crew from zero G stations to a station with simulated G. That way they could stay in space longer while minimizing some of the issues on the human body that zero G has long term. This avoids the expense of sending new crews all the way from earth every six months. Someone might stay up for two – three years. Two months in zero G, one month in .7 G, two months in zero G etc.

4) A hospital. It might be difficult for many medical procedures in zero g. Or zero g might help some medical procedures.

5) A hotel. Want to go into space but afraid you’ll get sick in zero g?…

Once you’ve got the first one, people could live on it indefinitely.

Second point.

How would society change in our slow spread to the stars? Habitats in the deep Oort Cloud could be 50 years travel from earth by the fastest ship. It would take a thousand years to travel to the nearest star by this method. The nearest star is 4 light years away. If we reached several stars in different directions the furthest points would take 8 – 10 years to send a signal by light and 16 to 20 years to hear back. Their last common ancestor would be 1000 years in the past. Would we split into separate species after a few thousand years more?

I see.. so a couple of meters of water can replace the earth’s magnetosphere and 100km of atmosphere.. .

In a word, yes. (So long as the water is protected from UV dissociation and subsequent loss, which it will be by the hull material that contains it.)

Solar radiation is actually only a problem for land life. It’s not and never has been a problem for marine/aquatic life. A few meters below the ocean surface, there’s essentially no stellar radiation exposure.

No, this is not an engineering problem. It is an economic problem.

If you can point to a series of off-the-shelf, available for immediate purchase technologies that, together, make it feasible, with the only barrier being that the cumulative cost of all those tehcnologies being prohibitive, then it is an economic problem only and not an engineer problem.

Otherwise, it is both. (Pretty much every engineering problem is also an economic problem, since solving engineering problems requires money….)

Likely, the multiple Habitats would need to be constructed either in orbit around Pluto (weak gravity well at the Solar System’s outer gravity well) or in some advanced space base in a Plutonian-region orbit. (One advantage to this scenario is use of Kuiper Belt asteroids/planetoids for mining.)

Again, don’t think Pluto (which is inner Kuiper belt), think outer Oort Cloud.

Or basically, we won’t be going from Pluto to the next star. We’ll be using Pluto as a staging area for going into the outer Kuiper Belt (which will range out in distance to several times the distance of Pluto’s orbit), and then from outer KBOs to the inner Oort Cloud, and then from inner Oort Cloud objects eventually to outer Oort Cloud objects. And then, only finally then, do we go to the next star.