Are there commerical/industrial possibilities (other than tourism) in space travel?

Great Debates
41

Two things I can think of right off.

1)It would add a phenomenal amount of mass to the ribbon (remember, this is a cable about 100 megameters (100,000km) long), which would almost surely make it too heavy to hold itself up. In the ribbon of the elevator, there’s really no such thing as non-load-bearing–either you hold up your own weight, or something else has to be made bigger to hold you up.
2)Unless you work out a way to make the cable superconduct, there would be a lot of loss over 100 megameters. No ground-based power cable is even close to that long, and they have huge losses. Near the top of the elevator, there’d be no power left to tap. [Technically, you only need power up to the Clarke orbit. After that, the lifter would fall away from Earth naturally. But I think it would still need power to brake, otherwise it would hit the counterweight at high speed.]

Another common suggestion is to include a lot of batteries or some sort of reactor on the lifter to power the lift. If you do that, you get the same problem rockets have: for every kilo of payload, you have to ship along kilos of power-stuff, be it hydrogen-oxygen fuel, fissile material or batteries. You end up not being a cheaper way to orbit. Beaming the power from the ground allows you to be almost all payload.

42

It’s not nearly as bad as a rocket, though. You don’t have to carry reaction mass. Crawling is a far more efficient use of power than rocketry. I don’t know the exact numbers, but I’d guess that it’s several orders of magnitude more efficient.

43

From their site:

Hmmm . . . Why at sea? (Is it just because the U.S. has no territory on the Equator?)

44

A few thoughts:

While the idea of invaluable space industries and the unique products they could produce in microgravity sounds good in theory, the actual transportation costs, skilled labor, overhead of maintaining a habitable environment, and capital investment in developing the technology make it prohibitive from a cost-benefits standpoint. Even if you can make, say, some kind of super-strong crystal-fiber matrix composite that replaces normal structural materials, the cost is going to be so high that it won’t be useful in any but the most exotic applications. Think of it as the difference between a commodity x86-based desktop machine versus a high-end SGI Origin server; the SGI is (or rather, was) clearly the better hardware for doing certain types of operations (graphics rendering and visualization), but the PC was so cheap and demonstrated profit margins based on economies of scale that development of it outpaced that of the MIPS processor…and now your typical renderfarm is a few hundred x86 or Opteron boxes using MPI, and SGI is in recievership. The only space-based industry to date to show a healthy profit is the telecommunications industry, and that only because of heavy government investment into the underlying launch, networking, and computing technology combined with a pre-evident manyfold expansion in bandwidth demands. It’s possible that some expansive, insatiable demand could develop for zero-gee pharmaceuticals or exotic high strength materials, but it would require both foresight and heavy, long-term investment to make this the driving force in developing commerical space industry.

There are, of course, an enormous wealth of metals available for the taking; a small, mineral-rich NEO likely has a greater mass of industrial metals than we could hope to extract from any single flatland mine, and without serious complaints about strip mining or environmental hazards. (There’ll no doubt be a few well-intended flakes who want to protect an asteroid from exploitation, but without a spotted owl or baby seal in sight it’ll be tough to garner public opinion.) However, aside from the costs, again, of getting their and paying your labor force, it’s not likely to be a great investment vis a vis Earth-mined commodities. We don’t have any serious lack of structural or common metals like iron, aluminum, copper, tin, lead, magnesium, nickel, et cetera to the extent that a new massive supply would be competitive, and dumping a glut of rare earths and exotic metals like tungsten, tantalum, iridium, rhenium with make up such a small (if significant) part of the market would result in large price reductions assuming that someone doesn’t come up with new demands for these metals; even if they do, the new markets would have to maintain high enough margins to justify the decades of investment required to get to the point of exploiting these resources. What private, profit-motivated organization is going to take that risk?

The real reason to develop space industry and mine asteroids is because it is too expensive to haul stuff up from the Earth’s surface; permanent human habitats in space will have to become self-sufficient, space elevators, catapults, or any other cheap transport aside. It just costs too damn much, in terms of energy, to pull against gravity, and it makes no sense to ignore the big chunk of nickel-iron floating a few thousand kilometers away. But first you have to justify the costs of establishing human presence, and not in terms of value to itself. That’s a hard slog; talking about the hypothetical future of humanity, the drive to explore, spreading your eggs around, and so forth sounds visionary (and makes for some pretty good cinema on occasion) but it doesn’t incline most people to spend more than the price of a movie ticket. A few hundred billion dollars, in the context of developing vast new resources, gaining both abstract and applied knowledge, protecting Earth from catastrophic extraterrestrial threats, et cetera is a pittance. But come budget time at Congress, it’s an easy line item to cut out in favor of supporting the latest politically lucurative issue or holding a press conference about assigning your latest Golden Fleece award.

As for the space elevator; where there’s a will, there’s a way. People who claim that all the technical issues have been resolved, and that it’s merely a matter of basic civil engineering are living in a fantasy where undeveloped high strength materials can be cranked out in necessary and flawless form like knitting yarn and orbital hazards are minor irritations. On the other hand, naysayers who insist that it can never happen (or will be so absurdly expensive that it couldn’t even be considered) ignore the history of technological development from the wheel and axle through commerical air travel and high speed computing which was always ripe with pundits espousing the impossibility (either physical or fiscal) while the metaphorical ground was falling out from under their feet.

We’re not even close to being able to erect and operate such a thing today, and to try to do so might well exceed the trillion dollar estimate previously thrown out. But as the technology develops (preferably, guided and supported by parties interested in making it a reality as fast as development allows) and becomes both physically and economically feasible, the concept will go from being an impossibility to a mere engineering nightmare–just like every major, ground-breaking monument to the desire of mankind to do it bigger, better, faster, cheaper, and most importantly, with a big celebratory ground-breaking and giant Jumbotron screens advertising the latest in sweat-shop sports attire. It’s not going to happen in ten years or twenty, but if the next century rolls around with nary a serious effort in sight, I’ll be awfully surprised. I wouldn’t be surprise, though, to learn that the official language of the beanstalk is Manderin, Hindi, Malay, or Korean. (I have hopes that English will remain the lingua franca, 'cause I don’t think I’m up to learning an Oriental language after I pass triple digits, but maybe they’ll have a pill or something for it by then.)

Besides, one trillion dollars in the scale of (hopefully) millenia of human development and technical evolution? A drop in the bucket, a mere charged electron in a stream of plasma emanating from a solar flare, a fleeting trifle of opportunity cost well-spent. Ferdinand and Isabella pissing and moaning about the cost of three ships and ninety men for a fortune that built and funded an empire (albeit, one predicated upon suppressing the natives and ultimately squandered on excess). If it only costs one trillion, it’ll be worth its impulse in angular momentum many times over.

Stranger

45

This space lift thing has got me thinking

If one managed to produce a single filament that supported its own weight plus, say a small percentage for the payload, then one could equally well extrude a tube of the stuff, since each fibre is supporting its own weight.

At that point one could simply shift the payload on a column of hot :-} air, possibly assisted by suction vents at various altitudes, using wind. The whole thing could be a bit like a Pater Noster lift using air instead of steel cables (or whatever those things use).

A great way of ‘selling’ the project would be to present it as a Carbon storage mechanism.

46

Nope; since it’s losing energy, by slowing, you can use the deceleration process as a generator and gain power. Same principle as sticking a waterwheel in a waterfall, using a “falling” cargo pod instead of falling water.

As long as the mass going up and down is balanced, the only net energy loss should be due to the inefficiencies of the mechanisms involved. The pods going down can power the ones going up. You’ll still need a generator or battery of course, since the travel load is unlikely to be perfectly balanced, but it might even be a net gain if more is going down than up.

47

And radiology, biochemistry studies…

Isotopes are used in quite a lot of medical applications, mostly covered by the two large umbrellas I mentioned above. Other chemical pathways are also studied using isotope markers, but the “bio” label helps attract grant-givers’ interest for some reason :wink:

48

Partly that, but also partly as a hedge against something going wrong. It seems better, intuitively, to drop a payload into the ocean than on land, especially as it’s likely a city will spring up around the elevator’s base.

Of course, this neglects three points: First, if the anchor point is really that significant a nexus for commerce and other activity, then a floating city will evolve, Snow Crash style, negating that part of the rationale; second, as water is not compressible, dropping a huge object into the ocean will produce a pretty significant and probably destructive wave event which will affect people thousands of miles away; and third, if something really goes wrong with the elevator, it doesn’t matter where the anchor point is (see Red Mars).

49

So far in this thread we’ve had serious arguments for (or at least suggestions of) the technical and/or commercial viability of:

  1. Low-g or zero-g retirement communities in space.

  2. Live hands-on support for communications satellites, weather satellites, GPS satellites, etc. (consider that these things have been functioning well enough without such support up to now).

  3. Atmosphere-free astronomy (of course, the Hubble telescope already exists).

  4. Mining the mineral resources of extraterrestrial planets, moons and asteroids. E.g., mining the Moon for helium-3 (potentially nuclear-fusion fuel, if controlled fusion is ever achieved; not clear what else it might be good for).

  5. Relocating some industrial production to orbit, reducing industrial pollution of Earth’s ecosystem; use space-derived raw materials, ship only the finished products to Earth.

  6. Manufacturing in a natural hard-radiation environment – some industrial applications for that, including intentionally creating defects in crystals, curing of polymer coatings and paints, cross-linking of polymers, surface treatments for materials.

  7. Manufacturing in a natural microgravity environment – various industrial applications, including separations of isotopes by electrophoresis (products useful for nuclear explosives, also for radiology and other medical applications), growth of perfect crystals, manufacture of metal alloys, semiconductors, pharmaceuticals.

  8. Manufacturing in a natural near-vacuum environment – but there’s some dispute over how hard-vac the environment actually is or can be made, and I’m still not clear on what use that is for industrial purposes anyway.

(The potential of a “null-g sex industry” was mentioned; sadly, that must be discounted as essentially a form of tourism; remember, we’re talking about things that will take humans into space to stay.)

One thing hasn’t been seriously addressed yet: Solar power satellites. Is this viable or not? And how would the power be shipped/transmitted to Earth? Microwave beaming seems to have a lot of potential for environmental hazards.

50

It’s hard to say whether solar power satellites are technically viable; it’s almost certain, given a linear progression of today’s technology, that they are fiscally and logistically uncompetitive.

A single geostationary satellite would be a massive structure, requiring many launches plus orbital construction. The former isn’t terribly prohibitive if we assume that progression of competitive commerical launch vehicles and economies of scale–for a launch system that runs $200/kg you can assume a few hundred million in launch costs–but the assembly costs (assuming they require human labor rather than some kind of automated system) are going to be enormous, in the tens of billions of dollars. There are also maintanence and replacement costs; orbital space is a hostile environment, and regular repair (presumably by humans, or at least human-operated remote-control devices) will be required. This is possibly within reach of a government-funded organization like NASA or the ESA, but probably outside of what a commercial enterprise would undertake.

The structure, being in GSO/GEO (30-50km) is going to run right through the heart of the outer Van Allen radiation belts. This is dealt with on communication satellites by shutting down or isolating systems to help protect them, but I don’t think that would be an effective strategy for a massive solar power satellite. You could give the satellite an elliptical geosynchonous or even a periodic synchronous orbit to avoid the worst of the Belt, but then you are reducing power transmission efficiencies (beaming throgh a thicker part of the atmosphere or having “dark” periods where no receiver is in sight).

For a satellite in circular GEO orbit, your collector has to be near the equator, else you’re beaming through a substantially thicker atmospheric layer. This means that you then have to transfer the energy from your equatorial receiver to areas where it is demanded, which are predominantly North America and Europe. This will run into problems with line losses and throughput of the conventional electricty transmission grid. If you put it in SGO or a periodic orbit with a high apogee dwell time as described as above, you could place receivers at higher latitudes and collect energy for a significant amount of the orbital period, but you’ll still lose a majority of operational time. Multiple receivers spread around the globe could help with this, but then you’ll have to find the real estate (tens or hundreds of square kilometers) in different locations to allow for this. Mobile marine receivers could be used, but again you have the problem of transmission or storage of incoming energy.

The technology of beaming massive microwave energy (presumably in the terawatt range) is untested, both from feasibility and environmental impact. Advocates claim that the beam will be sufficiently unconcentrated to not do harm to a bird or aircraft that wanders into the beam, and other schemes have been proposed to ensure that leakage is prevented by use of a targeted focusing mechanism, but that’s all just theory for now. There are sufficient unknowns to make it difficult to predict what the actual problems and costs will be.

Compared to ground-based solar power facilities (about which the costs and problems can be reliably estimated) solar power satellites just aren’t in and of themselves a compelling argument. (Gerald O’Neill argued the case for them, but more as a justification for building the eponymous habitats, and then on a scale that is only feasible given an existing large scale space mining and construction industry.) It might be possible if you already have the infrastructure in place and the technology developed, but arguing for financing the development based upon speculation of their effectiveness is a hard point to justify. Like most speculative technologies, it’s a chicken-and-egg problem: if you have the technology, you’ll reap the rewards, but only if you have capital to develop the technology. For the most part, the only time we’ve been able to overcome an inertial resistance to funding such development is in response to political impetus; the “ultimate weapon” to win a globe-encompassing war, a race to be the first in some new field of human achievement, et cetera.

Stranger

51

Hmmm . . . I don’t suppose there’s any way to use the Van Allen Belts themselves to generate power?

52

Possibly. Robert Forward came up with the HiVolt concept to deplete the belts (to reduce the radiation hazard; if you can create or connect to a sink of reduced charge, you could presumably generate a current from the resultant potential. On a more general note, the ionosphere has a much higher concentration of charged particles than ground; an Earth-to-orbit tether could potentially create a potential difference that could be exploited. Whether either of these schemes are viable and cost-effective is another question. “Free energy” is only free insofar as it is available to be exploited; from a certain point of view, coal and oil are “free” save that you have to dig it up, refine/process it, and combust it. (Of course, solar, wind, and hydro don’t produce the kind of byproducts that fossil fuels do, and don’t create the radiation hazard of nuclear fission or D-T fusion.)

Thinking about the solar power satellite thing a bit more, there might be better ways to scale or distribute the cost, and better protect the overall system. Instead of building a massive, monolithic power generating array with a transmitter in GEO, you could instead build fleets of individual satellites or small arrays in a variety of better protected orbits, which would then beam power by laser or microwave to a single or small series of orbit-to-Earth transmitters. Even if you want to cluster your solar collecters, they don’t need to be rigidly connected together, if at all; you could tether them, using tidal forces to keep them tensioned and oriented, or let them orbit free and use small ion-dust rocket motors (drawing energy from excess solar power generation or during times when the satellite can’t connect to a transmitter) to maintain or move to an optimum orbit. You’d still have to validate the transmission from orbit to ground station concept, but you could at least select better orbits and distribute your overall system to limit environmental damage and hazard.

Depending on the cost of launching and deploying individual elements, you might not even need a human maintenance presence, which is likely to be the largest expense; you’d just replace as necessary, similar to communications satellites. Of course, that negates the justification for human exploration as a de facto requirement of the system, but reliable and inexpensive boost to orbit capability is the sine qua non of space exploration; once you have that, the costs of getting elsewhere become marginal rather than overwhelming, even with low I[sub]sp[/sub] chemical propulsion. (You still have technological hurdles to overcome, like radiation shielding and the effects of microgravity, but once mass doesn’t become a critical factor in your costs, you can expand your options.)

In the end, I don’t think you can justify human space transportation in terms of profit on Earth; it has to be justified in terms of itself, i.e. the benefit is that contributes to the ability to travel further and explore more. In many ways, human exploration just isn’t, and probably never will be, cost-effective, owing to the risk to and delicacy of human beings with respect to unmanned probes. The arguments otherwise generally come off, if well-intentioned, as specious and/or ill-informed. We should go there because it is interesting and unexplored, not because doing so will give us high-strength materials and exotic drugs.

Stranger

53

And so that we can be sure the human race can survive another ten billion years. That’s the most important reason.

54

There’s also this DARPA belt depletion plan:

55

“Another”?

It strikes me as being more than a little silly that we should be worried about the species surviving longer than the Sun can support life on Earth. No multicellular species on Earth has more than the tiniest fraction of that length of history under its belt. Our descendants in a billion years will likely no longer be Homo sapiens. And to be perfectly honest I really don’t give a crap how they’re going to be doing. I’m concerned about my daughter and her children and maybe their children but how people are doing 1,000,000,000 years from now isn’t worth a nickel to me.

56

That doesn’t matter. What matters is that they will be our descendants, that we won’t be an evolutionary dead end.

So far as we know, there is only one living species in the Universe that has the mental capacity to appreciate its beauty and wonder. Shouldn’t preserving its existence by a high priority?

57

I’ve said this before on this board: I have worked in biopharmaceutical research for the last 17 years and I have never heard anyone in the industry lament the fact that we can’t currently manufacture our drugs in a zero-G environment.

Realistically, it is a total non-issue, not even on the most distant radar screen of the most visionary pundits. It is a solution created by the space industry to a problem that doesn’t exist.

No. So far as we know there is only one living species in the Universe that thinks that the fact that it has the mental capacity to appreciate what it perceives to be its beauty and wonder is somehow significant.

58

My understanding is that it is not the manufacture of pharmaceuticals, but the research into them. If the active ingredient of a drug can be formed into a crystal where the active site of the chemical structure is exposed, and the chemical you are hoping it will interact with can be formed likewise, it’s easier to tell if the ingredient performs as hoped. Such crystals are more easily formed with a regular structure in zero-g.

As I said , that’s my understanding. I’d be interested to hear your thoughts on it.

59

From what I have been able to learn the research in this area which has been done so far (which I admit is technically fascinating) has mostly been funded by NASA itself. On the ground this is the kind of stuff that is usually done at large laboratories and universities and funded by the NIH or other federal entities. So the best that could be hoped for in the near term would be one arm of the federal government would be paying another for the use of their facilities, which I don’t really think would count as commercialization.

Drug discovery is already a very expensive business. Pharmaceutical companies tend to be very conservative and don’t normally fund much of this early stage research directly. There would have to be strongly compelling reasons to think that paying to have a particular molecule or class of molecules crystalized in space had a good chance of leading to the discovery of potentially lucrative drugs. I just don’t see your average big pharma executive thinking it was a good idea to shoot some of their money into orbit on the off chance they might discover some blockbuster.

The trend in recent years at the big pharmas has been more of a brute force approach, using automation and robots to screen whole classes of related compounds to see which ones could have potential therapeutic actions, and then following up on the ones that seem most promising in early tests. Therefore they don’t need to know right away what the active site necessarily looks like, they are only interested in it if it does something potentially useful.

60

:confused: What could possibly be more significant?