Mars Trilogy: Festival Night

Part of the Mars Trilogy Technical Commentary Series. Contains spoilers for this chapter and earlier chapters. Google Mars .kml. Literary commentary podcast.

The epic begins, as it must, in media res, with the major characters on a literal stage. Told from the perspective of the ruthlessly pragmatic Frank Chalmers seething with envy at John Boone, his friend and rival. The setting is Nicosia, the first city built on the surface of Mars, marking a transition point between the heroic age of Mars exploration and a later, more rapid period of emigration and growth. By the timeline, this occurs roughly in Earth year 2053.

Let us explore this alien world through the vehicle of its physical instantiation.

This chapter’s action occurs in the newly commissioned, and first of its kind, tent city of Nicosia. Possibly a reference to the Cypriot city partitioned in 1974, this city symbolizes a point of cultural transition between the heroic age of Mars exploration, in which the earliest settlers carved out a marginal existence mostly within underground bases (briefly glimpsed as “underhill” and “crater domes”), and a later period when non-specialist settlers move up en masse. The city has been constructed by an Arab/Swiss consortium, setting up a multipolar cultural backdrop and potential conflict between the old timers and new arrivals.

Physically, the city is described as having a triangular floor plan with transparent tent material strung over a spindly frame allowing people to live in a climate-controlled environment on the surface of Mars. Tents on the surface, most likely as a tensile membrane to contain pressure for a breathable atmosphere, enable the occupation of a much larger volume of space, per unit effort, than underground construction.

Because of its position on the surface with a transparent roof, Nicosia is supposedly able to see the flank of Pavonis Mons, the central peak of the three Tharsis mountains, an enormous shield volcano 8.7 km tall. In fact, the curvature of the mountain is barely more than the planet which, being somewhat smaller than Earth, as closer horizons. Nicosia would have a good view into the nearer canyons of Noctis Labyrinthus, however.

Even though the paint on Nicosia is barely dry, it already has a population of stray cats in the medina and mature sycamore trees in the park at its upper western corner. The first indicates a dedication to the built environment, while the latter indicates the presence of a sophisticated surface logistics network, capable of transporting large trees from nurseries to their desired locations through the intervening space environment.

The city has a population of around 5000 people, which is barely a small town by Earth standards but evidently quite large for Mars at this point in the story.

The tent material is joined to the ground by a waist-high concrete wall, presumably bedded deeply enough to avoid air leakage. I suspect a metallic membrane would be less susceptible to cracking, particularly as we now know that Mars soil properties are odd by Earth standards. Heat from within the tent will gradually melt permafrost beneath and shift the ground.

The tent membrane is composed of four layers of clear plastic. The outer layer generates electricity from the wind using piezo-electricity. While the net energy flux of the ambient katabatic winds on the east flank of Tharsis is unlikely to be high enough to meet Nicosia’s entire demand (probably around 50 MW), contact between wind and non-conductive materials does produce static electricity, and charge accumulation in vacuum is a constant challenge for designers of spacecraft.

The inner layer of the tent captures radiation, protecting the inhabitants. This seems dubious due to the sheer lack of cross section in a thin layer, but a tent that is high enough (100 m or so) contains enough air to shield most energetic solar particles. Only cosmic rays would get through, and there’s not much that can done about those short of 10 m of dirt. Speaking of radiation, Frank mentions that people on Mars take 15 rems per year, which is 150 milliSieverts using more modern notation. According to the RAD instrument, the actual number is closer to 250 mS, which is pretty close. Frank’s dosimeter probably gets a break because he spends his sleeping hours in a more shielded location than out on the surface.

Frank notes that the tent material is marked “Isidis Planitia Polymers”, referring to a Mars-based factory that produced the membranes. The Mars Trilogy universe is, at this point, more cargo constrained than we are likely to be with Starship, but even though thin plastic layers are relatively area efficient it is probable that we will pursue local production of plastics. Of course, we can’t make plastics on Mars without a synthetic hydrocarbon supply chain, an emerging technology likely to reach maturity on Earth within the next decade. The material itself is given as polyvinylidene difluoride, an extremely inert plastic related to Teflon. ETFE is another similar fluoridated plastic routinely used as a tensile roofing material due to its UV resistance.

The town’s designers went to significant effort to give it a natural feeling, with a description reminiscent of Christopher Alexander‘s work on design patterns. That said, the climate control systems are described as producing an artificial snow flurry in one section and are evidently capable of keeping the city warm and sycamore pollen under control!

Below the town is the farm, described as bigger than the town, kept 15 C warmer than the town and with a CO2-enriched atmosphere. Long beds of barley and wheat apparently grown in Mars dirt, which is described as being carefully engineered, probably with fertilizers and various microbes. For narrative reasons, the farm isn’t directly conjoined to the city though there is no engineering reason it couldn’t be. It appears to be lit with natural light, which on Mars is about 2.5x weaker than on Earth, or comparable to solar insolation in northern Finland during the equinox – a place cold enough that trees grow but agriculture is not really practiced. Therefore it seems likely that natural light would be supplemented by additional lights suspended from the ceiling.

The description of the farm is a good place to jump off into a discussion of the politics of labor, which occur throughout the series. At this point in the narrative, it is not clear how mechanized/automated labor is on Mars, a place that will always have a terrible labor shortage and strong incentives to automate stuff.

At the beginning of the party, Frank sees construction workers, whose work is now done, getting drunk on vodka. This speaks to an image of construction involving hard physical labor and a hard drinking culture. At the same time, this is a city that has just been built, complete with trees, on the surface of Mars. Times have changed since the invention of the skyscraper. This dissonance recurs throughout the chapter. Who does the work around here? Frank stares at his reflection in the window of a boot factory, representing a labor intensive cottage industry. How many shoes would need to be hand-built in a town of just 5000 people? Would the factory need a store front?

Later, he raids a farm work station for certain chemicals. This work station is definitely human centric, and as described is appropriate for a small garden, rather than a farm capable of feeding 5000 people, which would probably be bigger than 60,000 acres (28,000 hectares) and involve, even on Earth in 1990, lots of mechanized planters, harvesters, and crop dusters! Still, Frank needs certain pesticides to orchestrate a murder or two, which again poses questions. Even today, climate controlled farms can survive without pesticides because they can control inputs and outputs and easily sterilize a growing area. What pests do the Martian farmers need to control on a brand new farm situated in an otherwise unlivable vacuum? Back to pesticides, it’s clear this book was written in a pre-Google time, in which an incriminating search history on Frank’s computer would close out this narrative quite quickly. It also seems odd to me that pesticides, applied in patch form to plants, could possibly be dangerous to humans in a combination and stored, unlabeled, in the same drawers. Okay, it’s a story. I’m glad KSR isn’t handing out instructions on how to murder people.

Back to labor. A construction site in the city is described as having magnesium beams, bricks, sand, and paving stones. Magnesium is not routinely used for buildings on Earth but it is a very light metal, and has nice material properties. If the Martian supply chain favors electro-refining of metals over oxygen-intensive blast furnaces, magnesium and aluminium may be relatively competitive, particularly if electricity is cheaper relative to labor than on Earth. As it would have to be for the economy to have any hope of closing.

The closing moments of the chapter occur in a medical center, brand new, staffed by human doctors and nurses. Even in KSR’s future, the hospitals are staffed in relatively traditional ways, by mostly nameless, anonymous professionals who have immigrated from Earth.

In this chapter, we get a glimpse of psychological stuff, though through the context of Frank’s general skepticism on the topic. In a way, it functions as a snapshot of the late 80s, a period in which KSR was a young father living in an experimental community in California, and is of course subordinate to the needs of the narrative. We get a mention of the “first hundred,” an international set of highly competent settlers out to build the first permanent base on Mars after, it turns out, just one earlier mission. Against this backdrop, we have conflict fomenting between a faction that wants to maintain a laissez-faire libertarian hyper-American syncretic culture, and one that would import much of Earth’s regulation and legal framework. Contrasting this, we have a suggestion of Frank as a jilted lover unable to “take the L” despite existing in a world where he’s a mature and competent leader with significant fame. To be frank, Frank’s sexual politics come across in 2022 as quite conservative particularly in contrast to some of KSR’s other work, especially as he muses that Nicosia may repeat some famous experiments on rat overpopulation, also referred to in children’s classic “Mrs Frisby and the rats of NIMH“. The implication, to be explored over the course of the narrative, is that the artificial, high pressure and isolated environment of the First Hundred did, in fact, change something about that set of humans despite Frank’s description of the boredom of their восхождением as a “long train ride”.

Let’s talk about the physical environment. Only a few moments of this chapter occur outside, on the Martian surface, and it is here where KSR’s talent as a writer of physical environment really shines. “The planet … is a dead frozen nightmare” as seen by Frank, at least. The surface is duricrust, a desiccated surface stripped by wind and cemented by precipitated salts, such as are seen in parts of Utah and Nevada. The winds come down off the Tharsis ridge, blowing towards the east.

People’s experience of this environment is mediated by a “walker”, a space suit adapted for surface activities. Employing writer’s privilege to elide certain technical difficulties, the walker is never described in technical detail but may have been envisaged as a mechanical counterpressure suit, a type of suit that uses mechanical, rather than gas pressure, to avoid vacuum damage to the human body. To combat the fierce Martian cold, they come with electrical heaters in a diamond pattern. Most heat loss for humans on Mars would be radiative or conductive through points of contact with the ground. Mars’ atmosphere is too thin to convect away much heat.

The sunset is deep violet, with yellow cirrus clouds. Mars’ lower gravity means that the atmosphere scale height is higher than Earth. On Earth, the scale height, defined as the point where pressure falls to 37% of sea level, is about 8.5 km. On Mars, it is around 11.1 km. Mars’ atmosphere is about 100x thinner than Earth’s, such that its thermal opacity is close enough to zero that it doesn’t have a convective troposphere like Earth – heat can radiate effectively directly into space. Nevertheless, a higher scale height allows clouds to form at higher altitude, where during the sunset they are illuminated by the full sun.

Mars’ day is equal to 24 hours, 39 minutes, and 35 Earth seconds. This is quite close to Earth’s, especially compared to other planets and moons in the solar system. Still, it presents a conundrum for timekeeping. If we keep seconds as a useful universal unit of measurement and build a traditional 24 hour day on top of that, we are left with 39.5 minutes of extra time per day to dispose of. KSR’s solution in the Mars Trilogy is to avoid some kind of awkward shorter leap hour and simply pause all clocks during the “time slip” at midnight, though it’s not clear how that’s handled in different time zones. It’s also a neat reference to a Mars time travel work by PK Dick, who KSR studied in graduate school. It also creates a neat narrative device – 39 minutes of extra time during the witching hour. As a lifelong night owl, I would appreciate an extra 39 minutes to work and sleep each day!

Parts of Nicosia’s streets and buildings are faced with red granite. Mars’ surface is actually very low on granite, as the rock typically forms deep within the crust (think roots of mountain ranges and continental crust) and Mars hasn’t had enough orogeny to expose granite at the surface. Outside of a handful of craters, it doesn’t exist near the surface. Granite, however, is the main rock type present in the awesome California Sierra Nevada mountains, which form the subject of KSR’s latest book and his favorite mountain range.

15 thoughts on “Mars Trilogy: Festival Night

  1. Does it give any indication of how thick the canopy is? It’s not going to block out all cosmic rays, but a canopy made of that kind of hydrogen-rich polymer is going to seriously cut the cosmic ray radiation dose even if it’s only about a foot thick. 10 grams/cm^2 of HDPE or Kevlar on ISS cut the cosmic ray dose about 55% :

    That’s about 5 inches thick of the stuff. If you can cut it in half again with another 5 inches, then you’ve got from 250 mS to about 63 mS – pretty close to what we already tolerate for radiation workers. And as you point out, that doesn’t factor in sleeping in more protected areas (you’re not just standing under the canopy 24 hours a day).


      1. How thick was your proposed canopy on “Domes are overrated”? It looks like you’re aiming for 1.5 kilograms/square meter.


      2. That would be about a mm. But 100 m of air is roughly equivalent to 10 cm of water.

        Even better! Even if the canopy is not blocking much because it’s thin, that plus other measures like shielding houses and buildings could get you below 100 mSv/year. And if you’re doing the thicker canopy, then you’ve just halved the dose again down to about 30 mSv/year – add in the localized shielding and you might be close to what places like Denver get in background radiation, at least if you’re not spending all day outside of the canopy in a space-suit.


    1. I will add that it does turn into a bit of a horror show in terms of mass. A canopy with the density of HDPE at 20 grams/cm^2 runs you about 126,000 metric tons for a canopy with 1 kilometer radius and 100 meters in height.

      If you wanted something with a radius of 3.5 kilometers (so that standing in the center of it, it would appear to stretch from horizon to horizon and provide about 9500 acres in land area), it would be about 440,000 tons. That’s not including any mass in cables necessary to anchor it.


      1. Notice that the air under the canopy would have about as much mass, or more, depending on the pressure they settled on. From that perspective, the canopy isn’t so massive.

        Liked by 1 person

      2. Assume 1/3 normal Earth air pressure. That would be feasible, still allow for some buffer gas, while reducing structural loads. Air pressure would be about 34kN per square meter.

        Now, Spectra is a pretty decent structural fiber which can be made from nothing but CO2 and H2O, and in a very automated fashion. It has an ultimate tensile strength of about 3000 MPa, 3,000,000kN per square meter.

        With a very high structural margin, it takes about a liter of Spectra to support that load, roughly a kg. That’s a rough rule of thumb: 1kg of Spectra to contain 1 cubic meter of air.

        Granted, Spectra isn’t impressively UV resistant. You’d need a UV shielding layer on top of it. But that wouldn’t contribute appreciably to the mass.


  2. The “time slip” is Robinson’s tip of the hat to PK Dick. Considered closely for an advanced Mars civilization, I have always thought it would be unworkable. Would the trains stop running at midnight? Would people stop working? How could you have train schedules that made any sense across the slip and time zones?

    Mars is not Earth with extra minutes inserted. Mars would eventually need to enact a 62 minute hour, or a 62 second minute, or thereabouts. It could be the seed of revolution, throwing off the tyrany of Earth’s timekeeping.

    Your Mars series is great reading, and wonderfully thought provoking. Thanks.


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