Tuesday, April 27, 2010

Forbidden Planet

To the naked eye it is the loveliest of the celestial wanderers, from ancient times bestowed upon the goddess of beauty. Once it held a large and distinguished place in the human Solar System. In the pages of Heinlein its colonists rebel against tyranny not once but twice. That most unlikely of space SF writers, CS Lewis, made it the abode of the unfallen.

Then came the Space Age. If the Mars of imagination buckled under the weight of our probes, the Venus of imagination evaporated like whatever seas it might once have had. Real Venus resembles the abode of the fallen, in a theology far sterner that Lewis's. No surprise that it has largely fallen from grace in science fiction as well.

Yet Venus is not less worthy of our attention than the other planets. It has gotten some love from the Russians, one probe surviving more than two hours on the surface, and sending back images. Hell, like Mars, has lots of rocks.

Venus is Earth's near twin, the Solar System's other large terrestrial planet. Like Earth it is still geologically active. It is the ultimate cautionary example of global warming, and we would like to know how it got that way. Did it lose its primordial oceans, or - formed closer to the Sun, and farther from the 'snow line' - did it never have significant water to lose?

If we are to explore the Solar System in person, not only from a distance, we will explore Venus as well, at least from an orbital station. There, teleoperators can control surface activity directly, without the 5-25 minutes of light lag delay from trying to do so from Earth.

To my surprise there has even been some credible discussion of colonization - not of the hellish surface but the upper atmosphere, with aerostats AKA balloons. At 50 km above the surface the atmospheric pressure is equal to Earth's, and temperatures are near the human comfort zone, 0-50 C. Human breathing mix is a lifting gas on Venus (with roughly half the lifting power per cubic meter of helium on Earth), so the entire gas envelope can contain breathing air. Venus gravity, about 0.9 g, is suitable for human health, while Mars' third of a g is probably not enough.

Humans could even go outside, in principle with nothing more than a breathing mask, though protective clothing against those sulphuric acid droplets in the atmosphere would be a good idea. And don't lean over that rail too far. It's a looong fall, and nasty down below.

Reaching an aerostat base from orbit is (relatively) simple. Getting back up is challenging but not impossible, Venus orbit lift being a shade easier than Earth orbit lift.

If you really want to walk on the surface, consult the psychological or religious advisor of your choice. Returning to aerostat level is straightforward, a skyhook balloon, but that and your cooling system should be very reliable.

Could Venus ever be an economic center? I believe that the most valuable thing we will bring back from space is knowledge. What is the price tag on what Venus has already taught us about carbon dioxide in planetary atmospheres? That kind of value can be difficult to 'monetize,' as they say in the biz racket, but the University of Venus might pull in some hefty patent royalties.

I'm not a big fan of Space Mining, but the surface of Venus is a strange place, apparently repaving itself every few hundred million years; perhaps its alien geology has produced concentrations of rare elements that we won't find among all those small rubble piles.

So, what might be the roles of Venus in the new human Solar System?

The image, from Wikipedia, shows Venus as it would appear through the viewport - with full dazzle filter.

Saturday, April 24, 2010

Twenty Year Mission ...

... and proceeding.

The awesome, unfinished voyage of the Hubble Space Telescope began with an epic blunder. The brilliant recovery that followed, and subsequent maintenance, upgrade, and repair missions, have made the Hubble a major contributor to human spaceflight. And that is entirely apart from its enormous contributions to our understanding of the Universe.

Like most people I mainly know the Hubble for its contributions to eye candy: those delicate traceries, spills of jewels, and titanic cosmic thunderclouds that fill our monitor screens and coffee table books. They are merely incidental to its real work, but they they are the starship viewports of our imagination.

Much more modestly, Rocketpunk Manifesto turns three years old tomorrow. This makes my 181th post here, and according to Google Analytics I have had about 25,000 'unique' visitors. Thank you all for dropping by, and a really major thank you to my commenters, who provide most of the value of this blog. Sometimes I'm actually afraid to read the comments in the morning, because it is like wandering into a seminar room on one cup of coffee.

Most of you have found your way here in the last year. My posting had languished after the customary promising start, until I decided about a year ago to put more consistent effort into keeping the blog up. A good many of you probably got here via Atomic Rockets, or its Twitter/Facebook feeds - a fact I note with some interest on my tech industry blog, TecTrends Monitor.

One thing that has pleased me from the early days of this blog is its international readership, with more than 40 percent of you living outside the United States. Canada is in second place, though lately the UK is giving it a run. One curious oddity: about 5 percent of my total readership comes from Calgary. I have no idea why.

Currently my largest readership outside the Anglosphere is, appropriately enough, from the other great spacefaring nation of our age, Russia. Taking my chances with Google Translate, Добро пожаловать!

I will be (cautiously) adding a few social media bells & whistles, after seeing how useful those tools have been over at Atomic Rockets. (And as usual, the image on Winch's Twitter feed page is tres cool.)

But fear not, my emphasis will remain the sort of long form blogging I have been doing here, and with the same general focus: Plausible space futures, and the branch of Romance that deals with them, with occasional excursions into history, fantasy, or whatever strikes me as relevant and interesting.

Use the comment thread to say what you'd like to see discussed here, or simply to say hello!

The image of the Hubble on orbit has long been the logo of my static website, The Observatory.

Thursday, April 22, 2010

Wars of the Rings

Rings of Saturn
Traveling through the rings of Saturn, no one sees anything. The jeweled crown of the Solar System is a hailstorm swirling without end around Saturn, a place where ships might pass close enough for visual recognition but never see each other.

I was reminded of this by a commenter who, a couple of posts back, linked to a section of the ever growing Atomic Rockets site that I had entirely missed. The Solar System's leading tourist attraction, gorgeously visible through a backyard scope, is a weird and wonderful place. The laws of physics are the same, but the circumstances are so different that most of our conventional rules don't apply.

The fine structure of the major rings is magnificent, but most astonishing is how enormously compact they are along the 'vertical' north-south axis. The main bulk of the brightest and most massive of the rings, the B Ring, is estimated to be about only about 5-15 meters deep on average.

Within this narrow band the clutter is amazingly dense. The B Ring extends from 92,000 km from the center of Saturn outward to 117,600 km, giving it a cross sectional area of 1.69 * 10^10 square kilometers. It has an estimated mass of 2.8 * 10^19 kg, thus 1.66 million kg per square kilometer, or 1.66 tons per square meter of cross section. It is mostly water ice, so if the whole B Ring could be compressed into a flat solid disk it would be about 1.66 meters thick - about a sixth of its actual average thickness.

In fact the B Ring is so dense along its center plane that the iceballs may coalesce into 'solid' skeins, endlessly dissolving and reforming.

Hollywood? Are you paying attention?

If there is any place for real, classic style space fighters, it is the rings of Saturn. Relative speeds in the immediate ring plane will be slower than jets, more like highway speeds, since you're flying through the hailstorm, and even the clear lanes between rubble skeins probably have a good many smaller bits and the occasional big chunk drifting through them. The farther you get above or below the plane - on a scale of tens of meters - the clearer the going and the better the seeing, but the more exposed you are.

Wingmen, cruising on each side of the center plane, switching off now and then to throw off watchers? Raiders slipping along the center plane, working their way like experienced rivermen between the skeins?

Any craft with a human crew is much hotter than the rings, more than 200 K hotter, and would stand out in the mid IR. But if you are also coasting along through the rings, your view along the ring plane is practically nil; you are driving, or drifting, though the hailstorm. An observer far from the ring plane has a better view, but the rings still provide an lot of background clutter.

And an observer far from the ring plane is fully exposed to view, and therefore fully exposed to fire.

If there are denser clumps among the rings - and a 400 meter moonlet has been found in the B Ring - these could provide a place of concealment for larger ships or habs. And those billions of tons of ice drifting around might even allow that Holy Grail of space stealth, hiding your waste heat signature.

The B ring is at about -200 C, so melting a ton of B ring ice requires about 280,000 Kcal, or 1.1 GJ. Thus you can get rid of a gigawatt of waste heat by melting a not quite a ton of ring rubble each second. A moonlet 100 meters in diameter has up to half a million tons of ice (somewhat less if it is a loose rubble pile with voids). Stick a heat pipe into the center and pump away; it will take up to a week for the melt to reach the surface - and until it does, the heat is all trapped inside.

At the end of the week, you just gather another rubble pile (less than a square kilometer of ring), and start heating its interior. Your abandoned heat sinks will gradually cool off, but at a very slow rate, its surface barely warmer than its neighbors, its minimal signature lost amid all the random jostling in the rings. A rogue hab could drift through the ring system leaving only the most ghostly trace of its presence.

And the rings are vast, the B Ring alone 25,000 km wide and more than half a million in circumference, so there is plenty of room to lose yourself in.

Yes, there is something tacky about planning space battles in the rings of Saturn, sort of like visiting the Grand Canyon and thinking of what a great shoot 'em up Western you could film there. But hey, spectacle you want, spectacle you got.

Now all you need is an excuse to be there. The only sure reason for humans to go to the rings of Saturn is that they are so cool, but battles between rival tour operators would kill the business. Gathering He 3 for fusion reactors is a popular explanation for going to Saturn, but not a convincing one. If you have fusion technology and deep space access, you can use dirty reactions to breed clean fuel. All you need is ice and a good safe distance from human habitats, neither of which requires going 10 AU.

More convincing (IMHO) is that we will go to Saturn because it is cool, and if we go in sufficient numbers we will develop an economy to sustain ourselves there. And humans can always find ways to get into conflicts, if that is what the plot calls for.

The image, from Cassini via Astronomy Picture of the Day, is backlit by the Sun, itself eclipsed by Saturn.

Monday, April 19, 2010

Transport Nexus II: The Prince versus the Discourses

Ambrogio Lorenzetti, The Effects of Good Government
Let us imagine circumstances in which space stations, habs, or orbital constellations might become effectively self-governing - thus, belatedly, filling in the starting point for this discussion thread.

It need not be the familiar Revolt of the Colonies. It could even happen without anyone quite noticing at the time. Suppose that major stations, following the prototype of the ISS, are typically joint enterprises, whether of states, corporations or other entities, or a mix. That in itself confers an element of administrative autonomy, since no single earthside sponsor has full sway.

If the station, like the Port Authority of New York, has its own income stream, it gains further autonomy. On the one hand, it has less need to keep Earthside sponsors happy, since they control no purse strings. On the other hand, keeping sponsors happy is easy, because it isn't hitting them up for money.

This could go on for decades, for generations, with the sponsoring authorities Earthside being 'honored but not obeyed, for they gave no commands.' a variation of obedezco pero non cumplo. In the end, everyone could simply agree to redraw the legal framework to reflect long established practice.

For story purposes, we probably want something more dramatic.

But set aside for a moment relations between nascent space cities and Earth, and concentrate on their internal politics. The most basic fact about space stations and habitats, of whatever size, is that they are spacecraft, and in most respects very little different from large 'ships.' Indeed the distinction may often be blurred, with ships in parking orbits providing station-type services, and stations being built where the building cages are, and flown out to their service destinations.

This implies an onboard command structure to assign watch bills, see to necessary operations and maintenance, and take charge in emergencies. For 'ships' this is entirely taken for granted. Even writers of libertarian stripe, from Heinlein on, have waxed lyrical about the Captain's authority.

Heinlein also had no doubt that the same applied to habitats. 'Sam Anderson' was speaking of domed colonies on a planet, not orbiting habs, when he told Max Jones that they have 'more rules than a girls' school,' but the principle is unchanged.

This is pretty stark stuff. For one thing it makes a steaming bowl of irony hash out of the deep rooted connection, at least in 'Murrican culture, between space travel and libertarianism. Yes, with a suitable array of oscillating hands you can have singleships and the like, but it would be far easier to have self-sufficient condos on the upper slopes of Everest or a continental shelf somewhere.

Other things being equal, outer space is not an environment for rugged individualists, or high tech counterparts of Jeffersonian yeoman farmers. [spelling corrected] For that you pretty much need habitable planets. (And for much else as well, a discussion I'll take up in another post.) Space, at Plausible [TM] midfuture techlevels, is an environment that calls for a high level of human cooperation.

It is, unfortunately, all too possible to achieve such cooperation in a dystopian, authoritarian system, but it is hardly necessary.

For one thing, whoever takes command in emergencies is not necessarily the final authority. Indeed, at the beginning they certainly are not: Station commanders are appointed by the station authority, itself initially established by Earthside sponsors.

In the scenario I outlined above, it is the this civil station authority that gradually establishes its autonomy, and indeed a key stage in asserting that autonomy would be appointing and if need be removing the operational commander.

Institutionally this whole process is not unlike the evolution of corporate governance since the 19th century, with the board of directors answering not at all to shareholders in most circumstances, and itself choosing both the company president and ultimately its own succession.

A space station is in very different circumstances from a business, and it is easy to imagine that the rather colorless role of administrative authority being subsumed by the station commander. From that point the story writes itself, and Old Nick Machiavelli provided all the plot tips you need in everyone's favorite work of political porn, The Prince.

But Nick wrote another book, the Discourses, which offered an alternate model of station governance - where the final administrative authority resides collectively in the stationers, exercised through something like a city council. In short, a republic.

A large space station is potentially fertile ground for republican institutions. Its population has a wide range of skills, and is accustomed in everyday life to working in teams where they rely on one another's expertise.

Nor it it hard to see how republican institutions might arise out of the circumstances I sketched above. When station administrators are first stretching their boundaries with respect to their Earthside sponsors, the stationers are their natural allies, while any internal disorder in the station slows the drift toward autonomy, inviting or even requiring Earthside sponsors to step in and clean up the mess.

A station-republic would still have pervasive government and constrained personal freedom by contemporary Anglosphere standards, 'more regulations than a girls' school' being a necessary fact of station life. But many restrictions will be irrelevant to stationers in any case; you can't have a backyard barbeque when you have no back yards. And there is a profound difference between having a say in the regulations that govern your life as against having them imposed from above.

Among other things, station-republics would be laboratories for studying what exactly freedom means.

The image is a detail from The Effects of Good Government, by Ambrogio Lorenzetti: a 14th century fresco in the Siena city hall.

Related posts: teamwork in space, and spacers.

Saturday, April 17, 2010

Worlds in Disorder

Crescent Neptune and Triton
Via Sky & Telescope, news that planetary systems Out There are even more of a chaotic mess than we thought before. Several newly discovered transiting extrasolar planets turn out to be orbiting retrograde with respect to the rotation of their parent stars.

This, to put it mildly, was not expected. Planets discovered by transiting, passing in front of their stars, tend to be 'hot Jupiters,' orbiting rather close in, since such tight orbits are more likely to have the needed edge-on positioning.

If, as generally assumed, planets form from a protoplanetary disk of gas and dusk, they should all be born prograde, and the subsequent encounters that might leave a planet in a retrograde orbit would be expected to produce large orbits, not small tight ones.

'The new results really challenge the conventional wisdom that planets should always orbit in the same direction as their stars spin,' said Andrew Cameron, who reported the findings to the Royal Astronomical Society. (How cool is that?)

An earlier Sky & Telescope article, which I missed at the time, gave hints of these findings, but also made a rather curious statement, from MIT exoplanet specialist Joshua Winn: 'Now we've gotten a glimpse of the weird, wild systems we've been hoping to find all along. Theorists will have a lot of fun trying to get the planets in these orbits.'

The observational study of exoplanets is only 17 years old, but this is a discipline that has already forgotten its origins. Its entire history has been one big joke on the theorists, with punch lines that continue to unroll. When haven't observed extrasolar planetary systems been weird and wild?

It's somewhat forgotten now, but the first discovered extrasolar planets do not orbit a sunlike star but a pulsar, a post-supernova remnant that was about the last place anyone expected to find planets. The first planet of a sunlike star, 51 Pegasi b, discovered in 1995, is a hot Jupiter, something so unexpected at the time that there was an argument over whether it was a 'planet' at all, or belonged to some other class of substellar object. (No one knew how soon planetary status even in the Solar System would become a matter of controversy.)

From a science fiction perspective, if anyone before 1995 had set a story in a planetary system typical of those we've discovered since (currently about 48 multiplanet systems are known), it would have been dismissed as implausible. I would have dismissed it as implausible. Jupiter sized planets in sub-Mercury orbits? Get real.

Big oops. At least for now it is our own system whose orderly grand-plan structure seems to be the exception. This itself may be a mere selection effect - if we were observing a twin of the Solar System, we would only just be able to detect Jupiter, and not yet any of the others. The extrasolar systems we now observe may turn out to be in the minority, the ones that happen to be easiest to find.

The obvious lesson here is that the universe is full of surprises. The only slightly less obvious lesson is that it is hard to project from a sample size of one. We will be surprised again, and repeatedly. Meanwhile, though, we have a lot more freedom of invention when it comes to planetary systems than we thought not so long ago.

The image, via Astronomy Picture of the Day, is of a crescent Neptune with Triton. (View the image carefully!) Chaos creeps even into our own orderly system; Triton is the only large moon in a retrograde orbit, and is probably a former Kuiper Belt object, captured during a Solar System past that is now thought to have been fairly turbulent itself.

Related posts: Extrasolar planets don't just orbit backwards. They collide, and take death plunges into their parent stars.

I should add (and just did, on edit) to treat the comments as a handy open thread for any pertinent - or even impertinent - observations.

Sunday, April 11, 2010

Transport Nexus

Cable Car with Bay Bridge
Many cities have acquired an icon in the modern sense: a signature image, usually a monumental structure, that instantly connotes it. The modern era prototype is surely the Eiffel Tower, famously visible from every apartment window in Paris.

San Francisco has two such icons, the Golden Gate Bridge and the cable cars, and it is a curiously interesting fact that both of them are transportation infrastructure. (Disclaimer: The bridge tower in the image is part of the Bay Bridge, not the Golden Gate, which is not conveniently juxtaposed with the cable lines.) I can't think of any other city that is so much symbolized by part of its public transit system. Perhaps the old classic London double decker buses come closest.

Bridges are iconic for many cities, well justified by the rule of cool, plus the symbolism. But not iconic for any great port city, that I can think of, is its actual reason for being, its waterfront. (Though I'd guess that the Ferry Building is iconic to locals).

Some celebrated facts about San Francisco, such as its hills and fog, are due to purely local circumstance. But most are rather characteristic of transport nexi. Far away from their own varied kitchens, people need to eat, so "half the town was restaurants, and all of them were good," an assertion still substantially true. People are far from their own beds, too, thus the other half of town.

Orbital stations are the well established transport nexi of space, going back to rocketpunk days. But science fiction has, on the whole, been slow to examine and exploit their potential. In written SF only Cherryh comes immediately to mind as treating space stations as much more than bus terminals.

(My reading is grossly fragmentary, and other examples are welcome, but I believe my overall point stands. Hollywood, on the other hand, discovered with if your 'ship' is a space station, it works like Dodge City. The action can arrive by stagecoach spaceship, and you don't need to create a whole new planet every week.)

One reason for the neglect of stations may be that that a large, ramified space station would be the most urban of environments, and space SF has a deep rooted anti-urban tradition. The colonists were always escaping an overcrowded Earth of dystopian cities, heading out to terraformed or extrasolar worlds of, well, wide open spaces. It was mid 20th century suburbanization on a cosmic scale.

Of the two writers who did most to shape our conception of space travel, Heinlein was fixated on the political ideal of the Jeffersonian yoeman farmer, while Clark had a William Morris streak, and tended to portray his idealized futures as a sort of rustic English exurbia. (Yet in The City and the Stars, the stasis of civilization is broken by Alvin of Diaspar, not by anyone from stuffily superior, rustic Lys.)

Isaac Asimov was an unabashed urbanophile - the man who gave us Trantor, after all. But he was not much interested in the details of space travel, and wrote very little rocketpunk. The Spacers in his robot 'verse, in fact, can be read as a fairly withering commentary on the standard vision of space colonization.

In Realistic [TM] space futures, stations may be not only the center of the action, but in human terms nearly all of it. A research base on Mars might grow into a college town, but activities such as mining are be highly automated. Human presence will tend to grow up around the transport nexi, for the reason cities always have, because that is where people are coming and going.

Even in an operatic setting of shirtsleeves colony worlds, my money would be on stations as centers of the action, and a network of stations might be the most 'natural' form of interstellar polity. Star Wars, with its rather Asimovian setting, puts one famous scene on a planet surface instead of a station, but still captures the essential Romance of cities:

"You will never find a more wretched hive of scum and villainy ... most of the best freighter pilots are to be found here."

The image is from a Ukrainian blog, mostly of automotive images.

As you may by now suspect, my absence from my computer last week was because we were visiting San Francisco. As soon as we can, um, put the financing together, we will be moving there to become true stationers.

Monday, April 5, 2010

The Good Shepherd

'Shepherd Moon' Prometheus
There is something vaguely sinister about this image from Astronomy Picture of the Day. Vast and backlit it glides through the black immensity of space as it has for eons, its shape vaguely suggestive of an ancient, battered ship. If anything is suggestive of the ever popular killer asteroid, this is it.

In fact it is a moon of Saturn, the 'shepherd moon' Prometheus, which along with Pandora governs the behavior of the F ring at the outer edge of Saturn's main ring system. I'll say again that the ancients blew it with Saturn: It should have been Juno, queen of the Solar System with her royal tiara. Far from sinister, Prometheus and his (astronomical if not mythological) sister merely help keep the royal jewels in place.

Over the last week or two, a couple of blog readers have emailed me asking for 'technical consulting' assistance in working out settings for hard SF or rocketpunk stories. I had to turn them down, because I hate making promises unless I'm sure I can really follow through.

On the other hand I'd be delighted to take part, and the hive mind of commenters has a lot of knowledge, far more than I do. So I am inclined to provide some comment threads for those discussions, starting with this one. (I also highly recommend SFConsim-l.) If there turns out to be enough demand, a companion forum could be set up for hard SF worldbuilding discussion.

Otherwise, regard this as an open thread. My own online presence will be minimal for a few days, but I'll try to drop by and say hello.

Friday, April 2, 2010

Yesterday's Tech Revolutions: The Stagecoach

Stagecoach Schedule
In Romance literature, stagecoaches exist largely in order to be robbed.* Like much Romance this has some roots in history: we had a couple of stage robberies in this neck of the woods, or California coastal scrub brush, back around the 1880s. Stagecoach service on the Central Coast ended as late as 1904, when the Southern Pacific Coast Line was completed.

Stagecoach robberies go back farther in England; at least I have an image of highwaymen that seems vaguely rooted in the 18th century. They cannot be much older than that, because stagecoaches aren't much older. The word coach comes from the town of Kocs, now in Hungary, whose wainwrights were turning out recognizable coaches from the 15th century, though it is a bit hazy when and where the body was first set on springs. Whenever it was done, for the first time it allowed 'civilian' vehicles, offering some trace of comfort, to travel at the speed war chariots reached 3000 years earlier.

But my concern here is with the 'stage' part, not the 'coach' part. Coaches were a (substantial) refinement of wagon technology. Staging them - operating them along a fixed route, on a regular schedule - was something new, and it revolutionized travel.

In England, so we are told, soon after 1660 a 'diligence' provided service between London and Oxford, about 90 km, a two day trip with a stopover in Beaconsfield. The name for the vehicle aptly conveys how impressed people were by the novelty of scheduled travel. By 1669 a 'Flying Coach' demonstrated a 13 hour trip, and soon the regular diligence was making the trip in a day.

But speed was nearly a side benefit; the really important thing was transportation that was reliable and above all available. Only the very rich could afford to own a coach, but people of relatively modest means could rent a seat in one for a couple of days to get where they were going. And 'travel planning' became more or less what it is now, not organizing an expedition. Within a few decades coach routes had spread across England, and improved roads, turnpikes, were being built for them to run on.

At roughly the same time there was a comparable developments in inland freight transportation, the spread of a navigational canal system - at first simply straightening bends in rivers or smoothing out rapids, but by the mid 18th century striking out on its own, sometimes through tunnels and over aqueduct bridges. Here the key innovation wasn't scheduling but the sheer magnitude and sophistication of the work, 'transportation infrastructure' on a scale not seen before. (Roman roads were strategic infrastructure.)

Like the stagecoach network, the canal network spread rapidly, transforming land freight transportation as stagecoaches transformed passenger travel.

And the point of all this is ...?

Long ago in its salad days, National Lampoon magazine called archery 'a crude attempt by Stone Age people to make a gun.' In much the same way, you could call those 18th century stagecoaches and canals a crude attempt by preindustrial people to build a railroad. The Canal du Midi was a crude attempt by 17th century French people to build a TGV.

The hardware of stagecoaches and canals is quaintly pre-industrial to us, in fact nearly the epitome of quaintly pre-industrial. But the 'software' was a precursor of the industrial age. The economy needed more transportation than the customary means of getting around could provide. In response, traditional materials - horses, wood, stone, and water - were combined with a new way of thinking about transportation.

And without that new transportation software, the waggonways and plateways that also appeared here and there in England at this time would have remained local oddities. The 'natural' way to harness steam for land transportation is a self propelled road wagon. Which also happens to be such a marginal technology that it never caught on, in spite of obvious utility, its culminating achievement being the Stanley Steamer.

Only in a culture where coach turnpikes and canals had already spread across the countryside would people have much chance of stumbling on the combination of technologies needed for railroads. And more to the point, if they had it they wouldn't have much use for it. A railroad in Alfred the Great's England would go broke, and so would a stagecoach line or canal company, because the economy wouldn't begin to support it. You'd have as much luck selling them iPads.

Tech revolutions arise, at least in part, because of this sort of pressure from below. When people want something so badly that they start pushing their established technology in surprising ways, some surprising things can bubble out.

I remember amateur zines put out by SF fans, wargamers, libertarians, and similar riffraff in the 1970s era, using copiers or even archaic memeo machines, that in retrospect feels like a similar precursor technology, a crude attempt by pre-computer people to create the Internet. These same people later turned up on bulletin boards and ARPAnet, doing much the same things they were already doing, and so gave rise to the Internet culture.

It may not always work out this way. Other societies, notably China of the Song Dynasty, had a similar proto-industrial sophistication, but no industrial revolution ensued.

The 'stage' in stagecoach is also, no surprise, the stage of multistage rockets. The orbital diligence has to carry its fresh horses on the stagecoach roof, which broadly is why it costs so much more to reach orbit than Oxford, even though you get there sooner.

This does not mean that some transformative new space techology is about to jump out of the woodwork. In fact, it gives good reason to think it won't. (Though it would be cool to be wrong.)

Our current launch tech, in fact, fits our current space needs pretty well. Worldwide we send up roughly a hundred orbital or deep space payloads every year, ranging from 100 kg or so to a few tons, sent into a wide variety of orbits. This has been fairly consistent for decades.

If we had a fleet of classic shuttles we couldn't use them economically; it would be like building a railroad in order to operate a monthly doodlebug. The most efficient way to support the traffic demand is more or less what we have, a stable of expendable types suited to varied launch profiles.

But if our space traffic expands to the point where we need proper stagecoaches and canals we will build them, and then perhaps something unexpected might come chugging out of the mines.

* For once TV Tropes is unhelpful here, because in the famed movie Stagecoach the problem was irate Native Americans.

A precursor of scheduled transport service was the Venetian merchant galleys, though the schedule was something like 'Departing Bruges every March or so.' Later, these ships were weaponized.

Stagecoach schedule image via Rajiv Patel, and I swear the latest image on his Flickr site is sheerest synchronicity.