Sunday, February 7, 2010

Pluto's Revenge: A Dish Best Served Cold

Surface Features of Pluto
Pluto may have been stripped of its full planetary epaulettes, but not of its ability to deliver surprises, and 'new' images from the Hubble delivered one. (Commenter Ferrard Carson alluded to this in a comment to the last post.) Pluto is undergoing seasonal changes on its surface, and with startling abruptness, considering that Plutonian seasons are about 62 years long. UV light from the Sun breaks up methane ice, leaving a dark sludgy stuff called tholin.

The methane ice and tholin put me in mind of Pluto in Heinlein's Have Spacesuit, Will Travel.

'New' is in scare quotes because the Hubble imagery was obtained in 2002-2003, but it has taken until now to process the information - far below the nominal resolution even of the Hubble - to tease out the information. The level of detail they were able to recover, as a rather charming aside, is comparable to our naked eye view of the full moon. Evidence of surface changes comes from earlier Hubble imagery dating back to 1994.

So Pluto now joins Earth and Mars among planets bodies whose surfaces change dramatically as a result of seasonal changes in surface ice.

Though from another perspective this behavior is also a bit comet-like, a reminder that the displaneting of Pluto, however much it crushed schoolkids (most got over it), was a byproduct of all we are starting to learn about the outer Solar System.


When I was a kid, Pluto was the lonely outer sentinal. Beyond was only interstellar night, and a few tumbling comets (though rocketpunk SF was fond of adding a tenth planet, often called Proserpina). Now Pluto is instead the king of the Kuiper Belt - Eris, slightly larger and three times farther out, belongs to a separate class of remote objects, the 'scattered disk.'

Instead of being the end of the Solar System is the near shore of an entire realm, orbiting in the solar twilight, only just starting to be known.


Related post: I contemplated the immense outer system last year.

57 comments:

Anonymous said...

Worlds wanting only the touch of light and heat to serve as new homes for the human race...steping stones on the shore of the ocean of night, from which we can launch our continuing voyage toward those distant, alien shores.

Ferrell

Citizen Joe said...

Hmm... Assuming some sort of interstellar travel, would you want a base on Pluto or would it be better to be closer to the center of the system.

In a probable derailing pondering, locally we've got some people pushing for a high speed rail connecting two cities that have traditionally been traversed by car on a highway (a pretty good highway at that). I've got a big problem because neither city is centralized so once you get to the other end, you need a car to get around anyway. Since it is only a 90 minute drive (maybe half that if the train goes through), and you'll spend upwards of half an hour on each end getting and dropping off the car, what exactly is the point?

Thucydides said...

Following Citizen Joe's derailing (and to think he also talks about high speed rail ;))

Pluto might be very interesting in its own right, and maybe attractive to colonists for some reason that might seem strange to us (or maybe not, a group of political or religious dissidents might find it a good place to settle and practice whatever faith they have without interference), but as a jumping off point for interstellar travel, it doesn't have the resource base.

For that you need to settle the Uranus system, where you have access to the mineral resources of the rings and moons to build starships, and vast quantities of 3He and Deuterium for fusion engines. Even the planet's mass is useful; a 150 million kilometre gravity whip can be built to "fling" payloads throughout the solar system (when the geometry is right) or to provide the initial boost to departing starships.

Bryan said...

Do you know what sort of processing was used to generate these maps?

Citizen Joe said...

The only thing Pluto has going for it is that it is so far out of the solar gravity well. If interstellar travel becomes dependent on warping of space, then getting as far out from the solar well as possible makes it a good 'base'. There's an RPG called Fading Suns that puts the interstellar gates way out there, although the likelihood of the gate being anywhere close to another body, unless they were put into synchronous orbit is very slim. I think Pluto's orbit is very inclined as well as dipping into Neptune's orbit occasionally. But that is probably endemic to the nature of the gravity well. The closer to the center, the faster you orbit and the less inclined the orbit. The other benefit is that when you are that far out, your orbital speed is insignificant and you're basically moving at the same speed as your star. At interstellar speeds, one side or the other of a star system is insignificant, but matching velocities would be easier with a large reference point like a star than some fast moving body like an inner planet. That still means a very long interplanetary shuttle hop.

Laurel Kornfeld said...

Pluto and Eris are both planets and Kuiper Belt Objects. They represent a third class of planets, the dwarf planets, in addition to the two classes already known, terrestrials and jovians.

Please do not blindly accept the controversial demotion of Pluto, which was done by only four percent of the International Astronomical Union, most of whom are not planetary scientists. Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. Stern and like-minded scientists favor a broader planet definition that includes any non-self-luminous spheroidal body in orbit around a star. The spherical part is important because objects become spherical when they attain a state known as hydrostatic equilibrium, meaning they are large enough for their own gravity to pull them into a round shape. This is a characteristic of planets and not of shapeless asteroids and Kuiper Belt Objects. Pluto meets this criterion and is therefore a planet. At the very least, you should note that there is an ongoing debate rather than portraying one side as fact when it is only one interpretation of fact.

As a dynamic world with geology and weather, Pluto shows it has more in common with the other, bigger planets than it does with most Kuiper Belt Objects except the few large ones, which should be considered planets too. Most KBOs in Pluto’s orbital path are tiny and do not have these features. These images show that before making definitive classifications, we should first get the data and analyze it; otherwise, we are defining objects without knowing significant factors about them.

Jean Remy said...

Planet or not, I can't see Pluto as being very interesting for anything other than than a few automated probes now and then.

As far as interstellar travel (if we want to stay firmly in the domain of hard SF, not fantasy) the most likely way to achieve the fantastic speeds needed to cross the gap between the star is probably a very big spacecraft carrying massive amounts of fuel, which may be catapulted either by a gigantic mass driver/railgun or a gigantic laser pushing system, or any number of serious and not so serious proposals. In any case the amount of resources and energy required will be stupendous, and since Earth has a leg up of several centuries in terms of industrial base (What I keep referring to as Industrial Depth) it makes little to no sense to ship all this to Pluto first. If you want to use gravity slingshots, Jupiter and even the Sun itself are more likely mass candidates than comparatively wimpy Uranus and Neptune. Depending on planetary alignments, bouncing said ship around a few planets makes the most sense.

Although this new data on Pluto is interesting, I don't think the planet/dwarf planet/Kuiper object is anything more than a curiosity.

Unless Charon is a frozen Mass Relay left behind by an ancient hyper-advanced race of living omnicidal sentient machines, of course.

Rick said...

Welcome to a couple of new commenters!

Billiards shots around any of the planets don't really make much matter when it comes to interstellar travel - it is like giving the Shuttle an extra boost by launching from the crawler while moving eastward.

On status, truth to be told I don't know whether it matters whether Pluto is a 'major planet' or not. In a way it is cooler, and at least as well suited to the name, for Pluto to be king of the Kuiper Belt, a properly shadowy realm. In any case the Solar System is a much more complex place than it seemed back when I learned the 'nine planets' as a kid.

I also don't know whether Pluto, or any of the outer system, will ever be of much utilitarian value to humans, or will simply be an Arctic of the imagination for space travellers.

Citizen Joe, I think you've outed yourself as being from Florida. The city pair doesn't seem ideal for high speed rail, but I suppose one argument is that over time transport creates its own urban geography.

I have seen this on a small scale where I live. Amtrak added a Pacific Surfliner stop near here, leading to a spurt of development around the station.

Citizen Joe said...

Yes, I'm from Florida. But general concept of high speed transport to a destination where you need additional transport can be applied to space. On the interplanetary scale, at what point does the high speed system make sense? Sure, we could get to Mars orbit in a couple months, but then what? We've got no base, we've got no means to reach the surface. No lift off... What's the point? But if you pack all that into a lift off from Earth, it becomes impossible with current rockets. We managed the moon shot and return, so that seems like we don't need the full infrastructure on either end. But does Mars need it? What about the outer planets? Interstellar? At what point is a built up infrastructure justified?

Ferrard Carson said...

Hooray, name-check!

I'll admit, most of my disapproval of Pluto's degradation was simply that I learned there were 9 planets as a kid and that Pluto was unique among them for having the weird orbit.

I guess the question of sling-shot vs. brute force would be the one that works more easily... and we've been brute-forcing stuff from Earth for quite a while. I like that term, "Industrial Depth" - although I somehow doubt any planetary system except Earth's is going to achieve any noticeable amount of it.

Now that I read Thucydides post again, he seems to be suggesting the slingshot mainly to get He3, Deuterium, and other stuff we mine from Uranus to other planetary systems, with boosting interstellar travel being a secondary thought / purpose.

I'd think that if we can achieve interstellar travel, it would be a negligible course correction to go from shooting for Sol to shooting for Sol III.

And nice reference, Remy. I'm playing through that game again, and I never fail to be amazed by the insane depths of the Codex. While some of the stuff is obviously stretching the bounds of hard SF, and eezo is straight-up magitech, it's all hand-waved in such a manner as to be very believable with minimum suspension of disbelief. I look forward to getting my grubby paws on ME2 with nothing but anticipation.

~ Ferrard

Jean Remy said...

Ferrard: ME 2 is excellent. I'm on my fourth play-through. (I had a total of 12 on the first game.) Codex in general is pretty good, especially about heat and spaceships, (though positive and negative current? What?) But yeah eezo is a Welsh lady, and she doesn't even sing that well (obscure reference to an earlier post by Rick-don't ask)

Oh, my term of industrial depth is indeed specifically for Earth. We've been building our infrastructure like sediment deposits, layer upon layer of development and technology, for over two centuries now. It cannot be duplicated on another planet, and even if we have a Mars colony for a hundred years, Earth will have another two/three hundred years more behind it. It's not a race the hare can win, the turtle just has that much headway.

Rick: Yeah I wasn't really thinking but gravity slingshot effects are negligible when you're talking about fractional-c speeds, so it really doesn't matter where you launch from.

I think the "Pluto as a starting point for interstellar flight" fallacy comes from a profound misunderstanding of interplanetary versus interstellar distances. Pluto is really not any closer to the nearest star than Earth. It's kind of like saying I'd rather depart from Gate 25 than Gate 24 at JFK when embarking for a transatlantic flight, with the added issue you'd have to build Gate 25. By hand.

Anonymous said...

I actually was speaking metaphoricly, but I'm glad that it has spurred so much commentary! I personnally think that Pluto would be a cool place to visit, for the purpose of exploration and planetary research...you never know what you might discover or what insights you might get from traveling there in person. As far as a 'jumping-off' place for intersteller missions; if it's an antimatter-powered starship, maybe the fuel depot/factory should be as far from Earth as possible.

Ferrell

Citizen Joe said...

Hmm... from my quick search on eezo, I see that it is zero mass element that gains mass when positive current is applied... In other words when you put a positively charged particle (a proton) in, it gains mass... i.e. the mass of the proton... This sounds suspiciously like dehydrated water.

Laurel Kornfeld said...

Pluto could end up being a lot more interesting than previously thought. It is one of several places in the solar system that could harbor a subsurface ocean which could potentially host microbial life.

Jean Remy said...

Curious, I read "positive current" as a complete science failure on their part rather then throwing protons at it. I was starting to think they run all their ships on DC current, otherwise they would go from zero mass to infinitely massive 60 times a second... might cause trouble while going at the speed of light.

Which how again do they accelerate a mass-less ship *past* the speed of light anyways?... negative mass? Can a negative mass go faster than light...

Nah, Eezo is magic, and poorly explained magic at that. I do like the point-to-point gateway system though. I think it could fit one of the Alcubierre Drive theories, as long as you send the other half of the gate at STL speeds.

Jim Baerg said...

Remy said:"As far as interstellar travel (if we want to stay firmly in the domain of hard SF, not fantasy) the most likely way to achieve the fantastic speeds needed to cross the gap between the star is probably a very big spacecraft carrying massive amounts of fuel, which may be catapulted either by a gigantic mass driver/railgun or a gigantic laser pushing system..."

If you are using a 'laser pushing system' or something similar with particle beams or pellet streams to get interstellar craft up to a significant fraction of lightspeed, then I think you are better off building lots of *small* spacecraft & using your laser (or whatever) to accelerate another spacecraft every few months.

If your system can achieve accelerations of 1 g it will take a few months to get to a few 10ths of lightspeed. So you push one spacecraft for a few months, do any necessary maintenance on the laser, then push another spacecraft, so the laser is in almost continuous use & you get lots of use for the capital cost of the laser.

Putting the laser in the inner solar system would allow it to use solar energy to power it, & make use of the 'industrial depth' of near earth space for construction.

The 1st such interstellar laser would be used to send a series of space probes to all the nearest stars, but if an interstellar colony is desired, the colony would receive a few tons of supplies or a few colonists in cold sleep every few months.

Citizen Joe said...

I am skeptical of the idea that one could maintain the laser on a target at the ranges we're talking about.

Jean Remy said...

I wasn't thinking the laser would push the ship very far, merely give it a little extra push at the beginning. I can't remember where I saw the concept, but it was probably used on lighter probes with Mylar sails. I'll look for it again.

Citizen Joe said...

The starship from Avatar uses laser propulsion to accelerate to fractional c (I think like 0.7 c). Supposed acceleration of 1.5 gees for 0.46 years... That puts the ship at about 10 thousand AU by the time it starts to coast....

Thucydides said...

Industrial depth is a concept that can only go so far.

Historically, nations with great "depth" do fine until something comes along which allows a competitor to leapfrog past, while their political and economic elites are unable or unwilling to make the required changes simply because the sunk costs are so great.

The Serenìsima Repùblica Vèneta had by far the best cannon making and shipbuilding facilities in Europe in the form of the Arsenal, but the growing importance of oceanic Atlantic trade and cast iron cannon made the galley wrights and bronze cannon casting irrelevant starting in the late 1500's.

Britain overtook France as an economic power despite the huge disparity in population since the English moved from craft industry (where France's population advantage gave them far more "depth") to industrial production.

The British Empire's great depth was overtaken in the late 1800's by Germany and the United States because these new nations were investing in the latest industrial plant rather than amortizing legacy equipment. The former Soviet Union has vast industrial depth, but no large pool of investment capital nor large markets, their industrial depth is turning into industrial compost.

Even more recently, I recall Arthur C Clarke pointing out that Sri Lanka was leaping from the telegraph age to the cell phone age, simply bypassing the huge investments in hardware required for providing conventional land-line telephones to everyone (Obviously major subscribers like government and corporate clients would receive land-line access, but it was faster and cheaper for customers and service providers to set up and use cellular networks).

So the "depth" of industry is important, but other factors like population, access to capital, amortization, the return on investment, the size of the market and even cultural factors can rapidly change the equation. In many ways Earth and Cis Lunal space will be the economic hub of the solar system for centuries to come, but this is due more to the sheer size of the market and capital pool than anything else.

Colonies will have to invest in the newest equipment possible and wring the maximum productivity out of their populations (either through market incentives or by becoming repressive hydraulic empires ruled by the life support elites) mostly as a matter of survival, and their rates of economic growth will resemble 1980's era Japan, China or the Asian "Tiger" economies. (you will note that even with their astonishing growth, none of these economies is anywhere near as large as the United States even today)

Rick said...

Spam comment elfed!

I agree that industrial depth is not forever. Gradually old technologies and investments become obsolete, and established leaders become complacent.

But some tougher conditions apply in space, namely that we have to re-learn how to do everything. The 19th century Japanese could study a British factory, then copy it in Japan. But you can't copy an Earth factory on the Moon and expect it to work.

This will generally slow down the growth of space industries, because they have to re-develop almost every technique. And for high value/mass products, which are most high tech stuff, the shipping cost from Earth to orbit is proportionally a lesser factor.

Which is why I think the time scale will be long.

UmbralRaptor said...

Do the problems with local production mean that it would make more sense to import everything that requires any industry? (Especially given that orbital spaceflight would be relatively cheap if off-earth colonies exist)

Thucydides said...

I suspect that there will be entire ranges of techniques which will be relatively cheap and easy for the space economy.

"Mars Direct" is based on atmospheric processing using gaslight era technology. Asteroid processing can be as simple as breaking off a piece, enclosing it in a plastic bag and heating with an aluminum foil mirror. Google has many other schemes to examine, and John S Lewis has written several books with detailed techniques for resource extraction and exploitation (I like Mining the Sky), so we are not going into Terra incognita.

So remass, basic volatiles, processed regolith for radiation shielding and other high mass, high volume bulk commodities will make up the largest portion of the extraterrestrial economy, while Earth will provide the high value added products. Think supertankers full of crude oil heading to America and Japan, and container ships full of iPods and cars heading back to Dubai for the early solar economy.

The other large scale export commodity that I can think of is energy, with fleets of large solar satellites beaming energy via microwave or laser to distant targets beyond the orbit of Mars, or to power high thrust, high ISP "packet" ships carrying valuable cargo (think of a VASMIR passenger ship without the honking nuclear reactor and shield). Jovian energy barons can fly electrodynamic tethers in the magnetosphere and beam the energy to Europa, Ganymede and Callisto for local consumption.

Rick said...

I tend to agree with UmbralRaptor's point. A large human presence in space won't even start to happen without cheaper orbit lift, and cheaper orbit lift makes Earth 'exports' more competitive.

A revolution in manufacturing tech could change that! But absent a revolution, I'm a bit skeptical that manufacturing in space will be straightforward, because we'll have to learn some of the most basic skills over again.

Having said that, we've achieved an important first step in showing that we can do Erector Set style assembling in space. (Surely some people here remember Erector Sets!)

I do agree that the first space production, by a long shot, will be bulk materials - most likely propellant, since that is by far the biggest consumable in space travel. Almost everything else can be and will be recycled, but when you burn propellant you kiss it goodbye and go your separate ways.

Jim Baerg said...

There is a plausible exception to the 'high tech/value per unit mass' stuff being made on earth for use in space.

If zero gee or high vacuum is required or at least helpful for the manufacture of something then making it in space is sensible. However, that space based manufacturing will mostly be done in cis-lunar space.

Rick said...

Agree. But so far, I haven't heard of any strong candidates.

Nano anything probably won't be helpful, because gravity is pretty insignificant on the nano scale. Which probably rules out things like drug manufacture, too.

I'd guess that the most promising areas would involve macro scale mixing or settling of materials, or funky things like the properties of fire in microgravity.

Cityside said...

"A revolution in manufacturing tech could change that...the first space production, by a long shot, will be bulk materials - most likely propellant"

It'll be interesting to see if this triggers any sort of ripple effect. Massive naval expansion (both RN and merchant)during the Restoration era led to increased demands for timber and iron cannon. As a result, ironworks turned switched to coke in place of charcoal. And, as coal mines drove deeper, mine owners needed more powerful pumps to keep them from flooding. Enter James Watt. Coal mines were among the earliest users of railroads, too (albeit, in the beginning, gravity and counterweight driven).

Sorry to obsess about the age of sail, but you stick to what you know, I suppose...

Rick said...

Decades before Watt, enter Thomas Newcomen!

Note by the way, that Adam Smith's The Wealth of Nations has only one reference to the 'fire-engine,' in a footnote. And though mine (horse/gravity drawn) mine railways were extending out of the mines and across open country, I don't think Smith mentions them at all.

He was acutely aware of improvements in technique, e.g. the famous pinmaking example, but the Industrial Revolution was sneaking up on him unnoticed.

So yes, refueling from space sources could have lots of ripple effects.

Thucydides said...

A few ripple effects occur to me now that I think of this some more.

1. LEO and Cis Lunar space become the "Japan" of the early Solar age, needing to import volatiles, radiation shield mass and energy, but the source of high value exports (either through importing them from Earth, or increasingly by manufacturing or assembling items in space). From a strategic perspective, the polities or corporations who own and operate facilities in LEO and Cis Lunar space will want to control their sources of raw materials and energy, establishing the geopolitical context of conflicts and relationships between the various parties. Resource producers will be in a poor position since they will have essentially one market while Earthspace can play various producers against each other. As well, Earthspace can field an effective navy to project force if they feel the need to do so.

A Balkenized Earth will have the additional complication that sending a task force to chastise a rebel asteroid colony might change the balance of power in LEO and on Earth itself

2. Since high tech will be limited and very expensive, these items will become heirlooms, and have their lives and utilities extended in ways the builders never considered. Social and economic position might be based on the ownership of working high tech items. While we might have cell phones, a laptop, desktop and consider changing them every few years, a space colonist might still be using dad's iPad in 2100 (that being the only piece of hardware, but backed by pretty advanced software).

3. Living space will also be divided between low tech plastic bags surrounded by layers of regolith and high tech "Park Avenue" type habitats. The expense of Park Avenues will make them rare, and they will have to be constantly refurbished and renewed, while the number of blue collar habitats constantly expand as the populations grow. Social position and wealth will become very stratified, but the numbers game always is in favour of the blue collar workers. If/when new technologies are developed that increase the productivity and economic power of the blue collar workers, the economic and social relationships will become inverted.

This brings us back to Pluto (via a huge diversion). When large numbers of blue collar workers become economically empowered, then the conditions arise for migration. People who feel discriminated against or who want to separate themselves from the prevailing social, economic or religious order will now have the ability to do so. Migration to places like Pluto or the Kruiper belt provides the distance and isolation these groups feel they need, and they will settle into isolated backwaters of the Solar system.

Laurel Kornfeld said...

Beware us empowered underdog rebels on Pluto!

Rick said...

It strikes me that natural resources in space have a peculiar economics. In most cases the sources themselves are effectively worthless, because there is plenty of the stuff around, just all hard to get to.

So the entire value of a mining operation is in the facilities, extraction and transport equipment, not the lode. I'm not sure of the implications, but very different from the familiar gold mining image!

Citizen Joe said...

While expensive, the Spanish treasure galleons were negligible to the value of the gold that was brought back from the New World. Never the less, gold was just a metal and the value was based on its rarity, not so much its usefulness. The glut of gold coming in would then drive down the value, with the lower limit based on the value of the ships and the other expenses to bring it across the sea.

I think there's also a huge copper (?) mine somewhere in SE Asia, one of those islands where they spent billions of dollars just to access the mine. I think the mine has paid for itself, but it takes years (decades) before it turns a profit.

So in terms of space resources, you're looking at capital investment, mortgage rates, life span compared to resource availability, production rates and sales. If the total cost over the lifetime of the 'mine' is compared to the total yield of the mine, a price per unit can be determined. If that price is less than the going rate, then there is profit to be made. Usually that profit margin needs to be huge to justify risks though.

Thucydides said...

Citizen Joe brings up some good points. The Spanish had a huge advantage in that they could exploit cheap (i.e. slave) labour to mine gold and silver, and that their economy could absorb the importation of precious metals (although the primary use was to pay standing armies to prosecute wars). An unfortunate side effect was increasing inflation throughout the Spanish empire, and spreading through Europe.

In space, I will argue that the costs of the actual exploitation is rather modest. You can bake water out of asteroids by breaking pieces off, enclosing them in plastic bags and heating them with solar energy. Other materials can be extracted by increasing the amount of energy via larger mirrors.

The real cost is delta V, which means boosting bulk materials from planets or large moons will be more expensive than free space sources. The high value manufactured items will pay for themselves regardless of source.

Trying to trace the economic, social and political consequences of all this is an interesting exercise.

Rick said...

Another subtle cost is the time cost of moving stuff around. Interplanetary ships have dreadfully poor productivity, months to years to deliver a single cargo.

This is one other reason that I think surface lift will be surprisingly competitive, once economies of scale can be realized (and if we can get operational robustness). Shuttles might deliver a cargo a week, spreading their cost over many more cargoes.

Citizen Joe said...

So long as the cargo isn't perishable, time may not be an issue. If a system is set up that lofts the material to its destination at regular intervals, you can still get your regular deliveries. Whether it takes 20 years to travel or just a couple months, you'll still get your weekly shipments. We've been spoiled by next day delivery such that mistakes in planning cost little. If you don't plan your supplies years in advance, then mistakes in space will be very costly indeed.

Rick said...

It isn't the transit time of the cargo that costs - it's the meter running on the expensive ship that carries it, and may take up to several years to deliver one cargo. (Compare to jetliners that deliver a load or two per day even on transcontinental runs.)

Citizen Joe said...

Oh I'm talking about chucking a rock with a transponder and then going back for another load.

The ship transport justification I've used is that they process the material en route so that they have processed material on delivery instead of raw ore. My specific example of that would be a refinery ship that takes ice from Uranus moons and then vacuum distills it to heavy water. Then cracks the deuterium out for D-D fusion. Then takes the He3 as fusion fuel and lets the Tritium decay to He3 as well. Due to radiation and such, you don't really want to be doing that sort of thing on Earth, but space is fine. The end result is enough fusion fuel for clean fusion (He3-He3) for all the Earth's power needs arrives every eight months or so. But the actual trip is like 6 years. The outbound mission may instead use ammonia ice as its cargo, again refining for fusion fuel but using the nitrogen to feed the gardens at the Uranus bases.

So, Rick is right about sending stuff as cargo on the ships. On Earth we have resistance that requires constant application of the engines to move. In space, once it gets going, the cargo will get there eventually. Thus no point sending the ship unless they are doing something with that power along the way.

Rick said...

Processing the material en route is the big argument for cycler stations - using the travel time to do work, not just thumb twiddling.

Shipping cheap cargo pods instead of whole ships could also improve the transport economics, but with constraints.

Take the example of Mars. Unless you have demi-torch performance (say, at least 200 km/s delta v at 5 milligee acceleration), you are on a ~2 year transport cycle. Even if you're using mass drivers to sling the luggage, they will sit idle much of the time, waiting for the next set of launch windows to come around.

Jim Baerg said...

"Take the example of Mars. Unless you have demi-torch performance (say, at least 200 km/s delta v at 5 milligee acceleration), you are on a ~2 year transport cycle. Even if you're using mass drivers to sling the luggage, they will sit idle much of the time, waiting for the next set of launch windows to come around."

I recall an Analog story in which part of the background was a major role for a settlement on Mercury because stuff launched from there by mass driver would have a launch window roughly every 90 days to any place in the solar system & the Hohmann orbit travel times would be smaller as well.

If there are customers in a lot of places within the solar system the mass driver would get almost continuous use.

Jean Remy said...

Don't forget the sunglasses and the suntan lotion.

Oh, and asbestos swim trunks.

Citizen Joe said...

Venus is hotter.

My 'future vision' usually puts transfer bases at the Mars-Sol lagrangian points 3-5 with another at Mars. Inside that, cyclers then run between Mars and Earth. I think that Venus ends up disturbing the Earth-Sol lagrangian points so the Mars orbit cycler bases are about the closest.

Thucydides said...

I think transport would be heavily segregated like it is on present day Earth.

Bulk commodities will be sent in unmanned and automated systems (even on ballistic orbits if shot by mass driver). Delivery "pipelines" will be established and you can buy futures on shipments drifting in from deep space for delivery a decade hence. (sharp speculators will know that the shipper is taking a big gamble, since forecasting demand that far ahead entails huge risks). If I were to identify how such systems would operate I'd go for mass driver boost coupled with low cost magnetic or electrostatic sails for in flight course corrections.

Passengers, on the other hand, are premium cargo, and it will pay to build fast packets to deliver them. A VASMIR ship with a 2Mw drive system can theoretically deliver passengers to Mars in 39 days, and fusion powered ships are predicted to be able to reach Saturn's moons in 2 months. "SpaceBlue" will offer fast service at low rates by including aerobraking at the destination end (which will relieve the tedium of eating packets of peanuts for 60 days in a row...).

Of course even a nuclear fusion powered "fast packet" will resemble a luxury cruise ship more than a Boeing 737 simply because you need to keep the paying passengers entertained and occupied for long periods of time, which leads to the interesting conclusion that passenger spaceships will be far larger than cargo pods (which can be thought of as 20' ISO shipping containers being sent out on their own without a container ship to carry them.)

Citizen Joe said...

There is a common assertion that people will be put into hibernation for long trips. That is probably a bad idea at some point since we'd only be healing while thawed out while we get continuous damage from radiation.

Jim Baerg said...

Citizen Joe: I think we should distinguish hibernation from totally freezing the organism.

It's more plausible to me that some sort of sleep with the body temperature lowered to a bit above 0°C would be achieved than total freeze and revival. Hibernation is done by other mammals after all.

In the case of hibernation there will be slow metabolism going on so repair of radiation damage is likely to be done during hibernation if hibernation in humans can be achieved.

Jean Remy said...

I think there was already a long discussion somewhere on the benefits/dangers/possibility of hibernation... somewhere... my Search-fu is left wanting.

Citizen Joe said...

I see 4 methods.
1. Normal sleep. Requires much supplies.
2. Induced coma. Possible now. Body still heals. Room Temperature. Requires special food (IV). Does not eliminate the need for supplies. Muscle atrophy.
3. Hibernation. Technology not available. Requires cold room to slow processes. Slowed processes slows healing. Front and back loads the food supplies (build up fat layer before hibernation and feed off that layer during sleep. Some muscle atrophy.
4. Cryogenic suspension. Technology not currently available. Requires constant cooling at very low temperatures. Probably very dangerous. No healing of radiation damage. Eliminates supply problems. No atrophy.

I suspect there are reasons to do all forms, even on the same ship. I like to reserve full cryo to military shock troops where they are more likely to die from a bullet than radiation sickness.

Jean Remy said...

We don't know if 3 and 4 are even biologically viable.

Sure there are mammals who hibernate. We are not them. Who knows exactly how the human body (and the human mind) would react to prolonged sleep periods. This might require modifications on the genetic level.

As far as full cryo, it's a pipe dream. We just don't have a way of freezing without ice crystals forming in your body and ripping apart every single cell in your body. The only way to conceivably do it would be to instantaneously lower your temperature to absolute zero to stop any change in matter. Absolute zero is about as reachable as the speed of light. You can always almost get there, but like the paradox of the turtle you can never quite *get* there.

Rick said...

Here is a previous discussion thread dealing with hibernation, cold sleep, etc.

I tend to agree that traffic will be segregated, somewhat spoiling the Serenity tramp freighter theme. OTOH, just as passenger trains have baggage cars, some low mass priority freight will go on fast passenger ships. And express freight tends to be the more interesting freight, anyway.

Citizen Joe said...

Well, what sort of transportation system would work well with the tramp freighter?

I suspect that the difficulty of interplanetary (and even interstellar) travel would require specialized vessels to do the bulk of the travel. However, once at the destination, you still need to disperse materials and land. So, multiple bases either in the asteroid belt or some other stable orbit would receive passengers and materials from various locations around the solar system. Material might be fired on a Hohman tranfer orbit and take years to arrive at the designated spot. Meanwhile huge passenger liners would exchange passengers at the same bases. Material and people would then disembark for the next depot. However, once you reach your final depot, short haul tramp freighters would take over and ferry things from the depot to the final destinations.

That could be very Firefly-esque.

Jean Remy said...

Tramp freighters? Like City-side I can see them of short-haul, not interplanetary trips. Say a Jovian Moon-hopper shuttle making trips between Europa and Callisto, or around Saturn hopping between the He-3 extraction station and Titan.

Jean Remy said...

Er I mean Citizen Joe, not City-Side, my abject apologies I got you two mixed up somehow.

Citizen Joe said...

The short haul is also where you want the higher accelerations to avoid accidents, pirate evasion and landings/take offs. There are certain ranges in which you might be able to intercept the long haul vessels, but beyond that you just can't catch them or if you do, you can't get back. Fuel loads and such would also dictate that you couldn't really hijack a long haul either. They would be specialized and loaded up with exactly what they need to fly their predetermined course. The long haul carriers would then become the defacto 'stargates' which 'teleport' you from one planet to the next. That teleportation just takes a couple months.

I would envision the long haul system to be a government run system where tolls are collected for use. This is sort of like the Interstate System of highways in the USA. A certain proportion of the cargo load would be pre-designated for its primary mission (perhaps fusion fuel shipments) while the balance of tonnage gets auctioned off to corporations, potentially creating a futures economy on long haul tonnage. Of course, your slot could be pulled by the government at any time, particularly if they need to ship military hardware. That also means that government inspectors can be on board and have several months to do customs research before reaching the destination.

Rick said...

Damn, I fell into the very convention I've been criticizing, thinking only of the deep space long haul, and treating orbital space as a point on the map.

Citizen Joe's scenario also fits with how we might expect the shadow side and indeed the whole private sector in space to develop.

In space, 'trade follows the flag.' We may go into space for primarily for knowledge, national muscle flexing, and other non monetary reasons, but once we are there, other activities will emerge by accretion, if only the way a research station on Earth can evolve, in favorable circumstances, into a college town.

These secondary and tertiary sectors are also increasingly far from official scrutiny, sometimes because of the Nelsonian blind eye.

All the fun stuff follows logically, or can be made to seem as though it does.

Citizen Joe said...

Once the long haul vessel system is in place, and assuming remass is available from space, operating costs would be relatively small. By contrast, the short range haulers have higher operating costs via getting out of the gravity wells. Not to mention landing fees and tonnage rental. Plus, they would need to supply all their operating supplies needed for the long haul too, assuming they are taking their ship out of local space.

I suspect however that ship transport would be at the very least 'dry weight' and then remass and other supplies would be shipped on a separate long haul. Going back to industrial depth, spare parts or even whole reactors might be shipped in from Earth, then either stockpiled or assembled into whole ships locally. That then implies lots of orbital depots and shipyards, another staple of the genre.

Now the question is: How big are these long hauls in order for the 'spare tonnage' to accommodate a tramp freighter?

Thucydides said...

Trade follows the flag isn't the only scenario. Max Boot's book "The Savage Wars of Peace" shows how the US Navy and Marines were created and expanded to today's global force because the Flag followed trade.

The US Navy and Marines were essentially created to deal with the Barbary pirates, and spent a lot of the 1800's sailing around the world to bail out Yankee traders, missionaries and other Americans who were getting in over their heads (and to ensure that the local potentates would follow the rules of "civilized" commerce and diplomacy).

Since we can expect many of the early space settlements might be government research stations and commercial enterprises, there will be very little military infrastructure to begin with, and soon some of these places might decide to declare independence, or become "failed states" and bases for pirates, mad scientists or whatever other bad guys fill your nightmares. As they start picking off commerce or sending waste on rogue orbits, the need for some sort of force to maintain order will become apparent.

This could take the form of a "coast guard", a local constabulary or a full fledged naval task force (although these forces will probably start small and grow as economic power and experience in space operations grows).

Jean Remy said...

I disagree very much with that last post. Space is first and foremost the domain of the military. In terms of technology and strategy, anyone who can fling a vehicle in space has the finger on a weapon of mass destruction, and no one is stupid enough to let it happen unchecked. The military will always have a strong presence in space *before* any commercial enterprise, historical precedent notwithstanding. We are past the age of innocence.

Rick said...

Currently the military has a large presence in space, but mostly 'strategic' in nature, e.g. spysats, while the military has no interest in human spaceflight. Bit civilian space presence has strong ties to the military industrial complex.

I could see these general conditions applying for a long time to come:

- Lots of mostly robotic military assets in space, mostly oriented toward Earth.

- Very limited overt human military presence in space.

- A civilian human presence with many quasi military characteristics.

Whether this is an optimal story setting is another issue!