Estimating Mars settlement rates

Question:

How to get to an industrially self-sustaining Mars settlement in the minimum time?

Previously I've approached the broader problem in a book (http://www.caseyhandmer.com/home/mars) and several blogs, focused on a transport roadmap (http://caseyexaustralia.blogspot.com/2017/05/a-roadmap-to-industrially-self.html) and potential sources of money

(http://caseyexaustralia.blogspot.com/2017/09/how-to-fund-space-settlement-where-does.html). In this blog I'll attempt to integrate previous knowledge and make projections about time frames and costs.

Edit: Now all the data is available (csv) so you can slice and dice it.

In the previous post, I used the following graph to explain the relationship between population and self-sufficiency under a variety of scenarios, including constant and linearly increasing cargo capacity. It turned out that the final result did not much depend on how many rockets were available when, but the timescale certainly does. In this blog, I will build on the SpaceX exploration architecture. The most fundamental bottleneck is the rate of rocket construction and launch, so we will explore how construction rate affects the population and self-sufficiency timeline.

This graph shows a schematic relationship between population (horizontal axis) and mass self-sufficiency (vertical axis) under a cargo-constrained Mars settlement scenario. The settlement begins at the bottom left and scales towards the top right, where at some population likely exceeding a million people they are sufficiently industrially diverse that they no longer depend on crucial technology to be shipped from Earth.

Before I dig into actual numbers, I'm going to state my assumptions. For better or for worse, a lot of space-exploration themed writing, technical or otherwise, does not hew to the best possible standards for rigor. Here, I'm not going to delve into religious disputes about asteroid mining, lunar fuel stops or any other peripheral concept that's not related to the core bottlenecks.

There are two primary phases of the settlement timeline. The first, corresponding to the region of the red line below the purple cusp in the diagram above, marks the phase where scaling population within the limits of cargo shipments is a growing challenge. Loosely speaking, this challenge peaks with the successful instantiation of ore mining and refining for every industrially relevant metal and chemical - requiring interaction with the raw, unfriendly Mars environment. This phase is also the phase most directly applicable to current technology and projections.

Assuming the first phase proceeds more or less as planned and everyone doesn't die, the second phase marks the rush from the cusp to full industrial independence. By this point in the program, at least decades after initial landings, technology at every point of the exercise will have evolved to the point where predictions are difficult to make in 2017. Specifically, I expect that the forcing function of extreme Mars labor scarcity will result in drastic improvements in rockets, automation, manufacturing, and so on. It is possible, even likely, that this flowering of technology will reduce the minimum viable technology population more rapidly than ever-expanding immigration increases it.

That is, at the point of the cusp perhaps 20 years after initial landings, best estimates may still place the minimum viable population at 10 million, at least 30 years away even if the population doubles each launch window. At that cusp, net immigration could be in the tens of thousands per window but will have to increase to 100x that, something I think it rather unlikely.

Instead, rapid improvements in extraction and manufacturing technologies will reduce the minimum viable population to less than a million and perhaps less than the tens of thousands. As this trend continues, it will be possible to launch entire self-sufficient cities in one go, and perhaps a few decades later Mars will have thousands of self-sufficient towns, even though the total population may never reach the 10 million originally required.

It is important to emphasize that self-sufficiency is represented in reality as more capability than practice, since trade will always help increase overall economic efficiency.

I will sketch a picture of phase two, but first I will provide some numbers. Afterall, if the first self-sustaining settlement doesn't get built, there'll be no way for the ones that come after.

Phase One

As I explain in my book, the hard part is getting rockets from Mars to Earth, and to a lesser extent, from Earth to Mars. Here, I'll explain the constraints on total shipping capacity, then build a model that creates a plausible shipping capacity roadmap.

A spaceship has a number of important properties.

Cargo capacity to the Martian surface. Based on the IAC2016 talk and subsequent tweets, initial SpaceX Mars ships will have a cargo capacity of around 300T to the Martian surface. Second generation ships may increase this to around 1000T, but further increases are limited by a variety of physical constraints including the thinness of Mars' atmosphere.

Whether it can be reused and rate of reuse. The Mars ship is composed of a space ship, a tanker, and a booster. Initial boosters and tankers will be flown 6-30 times to refill the spaceship. The first spaceship will fly to Mars, spend nearly 2 years on the surface making propellant, then fly back to Earth. While the first few spaceships will be put near the Smithsonian, later spaceships will be able to fly to Mars every launch window after the emplacement of a fuel/ox plant and storage by the launch zone. Much later, improvements in engines could permit two flights to Mars per launch window. Over this time, the total number of Mars flights a spaceship can perform before retirement will also gradually increase.

Rate of construction. These spaceships are super complicated and difficult to make. Initial spaceships could easily take multiple years to build. Over time, the construction time will decrease and a single line can make more of them per launch window, increasing the total number of spaceships. Additional parallel lines can be built, perhaps by other space agencies using related technology, which also increases the total number of spaceships.

So how many spaceships are there per year?

To answer this question I built a Mathematica model that takes as inputs a function for the construction rate of various types, and outputs all sorts of information about total flights and total mass. This model can be downloaded from my github at https://github.com/CHandmer/mars-cargo-model. But here are the key results.

This table contains a summary of all the different types and versions of spacecraft used in the model.

This is a reconstruction of build rate (per window) from the global manifest data. We see here that as Version 1 reaches rate Version 2 is in the early production phase, on a roughly 8 year design cycle. After 2042, Version 2 production dominates investment and an additional line is added.

This graph shows how spaceship production and reuse increase the payload to Mars year over year. From 2042, Version 2 lifts the total throughput by nearly an order of magnitude.

This graph shows the cumulative cargo transported to Mars, reaching the crucial million tonne mark in about 2052. Given that mass transport begins in 2027, this process takes only 25 years to achieve.

I had a couple of surprises when seeing the results of this model.

First, total payload capacity increases very quickly. The period of time for which an initial settlement is constrained by quasi-constant cargo capacity is basically non-existent. This actually makes sense heuristically, in that it's easier to build lots of spaceships on Earth than it is to build a complete industry in space. It has a positive consequence too, which is that if the general relation between population and mass independence is maintained, the overall population can be scaled up even more quickly than before.

The second surprise was that there is genuine utility to building a Version 2 spaceship with 3x the capacity - as it compresses the timescale to reach a million tonnes of cargo by 15 years.

So how quickly does the population scale?

This is another difficult question to answer, but assuming a population-industry trajectory like the red curve given in the first graph above, the total mass each sequential settler has to bring with them can be predicted and a population-mass relation extracted.

This graph shows the total mass payload per person, assuming that the first 10 people, landing in 2027, consume the 900T of payload then available, and that the residual payload is 500kg, enough for a person and the food they have to eat on the journey.

This graph shows how the cumulative mass shipped scales with population. The population reaches a million people as the cumulative mass hits 620,000 tonnes.

This graph shows how population grows as a function of time. Here, the population exceeds a million in the 2050 launch window, 23 years after first landing.

This graph shows the window over window fractional population increase. The population grows very rapidly in the first decade to around 10,000 people. This reflects the easy gains of rapidly increasing shipping capacity and gas/water processing for plastics and propellant. 10,000 people is enough to begin mining and processing of metal ores to complete the set of available Martian feedstocks for the development of advanced industry.

Window over window gains drop below 2 from 2045 as all available space in Mars ships is consumed with passengers. If further explosive growth is needed, more ships and more flights are needed to transport people.

What does it cost?

In the previous section we eliminated mass to discover the population-time relations. Here, we reslice the data to discover the mass per passenger on a launch window basis.

This graph shows that by 2033, cargo mass per passenger has fallen to about a tonne, putting a ticket within reach of a middle class family. Someone arriving in this launch window could be the 10,000th person on Mars, and will mark the transition from program-selected specialists to self-selected professionals.

In 2035, a Version 1 spaceship can carry about 300 passengers, each with a tonne of cargo. By 2044, a Version 2 spaceship can carry about 2000 passengers, each with 500kg of cargo.

Let's adopt some ballpark numbers. A version 1.5 spaceship+tanker+booster may be constructed for a price comparable to a modern composite passenger jet, say $500m. Each refit costs $100m (of which a tiny fraction is propellant), for a total lifetime cost over 16 reuse cycles of $2b, or $125m per flight. If this is split evenly in time and between 300 passengers in 2035, the per ticket cost is around $420,000. A version 2.5 spaceship+tanker+booster will cost $500m to build, $50m to refit, and fly 30 times. Split evenly, the per-ticket cost in 2044 is $33,000, for a $65m/flight total cost.

Unfortunately it is difficult to be more precise than this, due to multiple cascading uncertainties. By the onset of "general admission" tickets in 2035, many billions will have already been spent on development and construction of spaceships which may not recover their construction costs in regular service for decades.

That said, I can attempt to estimate development and construction costs. Design rate and cost for both spaceships is $500m and 20/window, which works out to around $4.5b/year. This starts at the beginning of the program, even if the production rate doesn't reach design rate until 8 years later. Thus construction costs alone reach $4.5b/year in 2022 and $9b/year in 2032.

Reuse costs are initially low due to low numbers of reused spaceships, but eventually dominate overall program costs. By this point, however, ticket revenue will effectively offset this cost, and eventually fund the construction of new ships and entire program.

The primary financial outlay, then, occurs between 2018 and 2040, and may total $132b at an average of $6b/year.

This graph shows how the number of ships built and launched varies over time. If refit costs are 20% building costs, then building costs dominate until about 2040, by which time general admission revenue can begin to cover much of the program's operating costs.

Model Limitations
This model is generated from rocket building history alone. It doesn't take into account any other aspect of the universe, including human mortality, accident rates, or the possibility of mission failure. While guessing numbers and adding them to the model is technically easy, I judge that it would greatly increase uncertainty (fudge factor) while not adding much insight. Model complexity is only useful up to a point.

Phase Two

Earlier, I defined phase one as the era of cargo constraint, and phase two as the era of accelerating returns. As we've seen above phase two has a different kind of restraint, namely an immigration capacity restraint. By 2045, the critical path for growth is how many people can fit on a Version 2 spaceship, although under nominal predictions a million people are reached only 5 years later, by 2050.

Here, I will wrap up by listing technology concepts that could lift this constraint and permit further high rates of growth into the future.

• Higher construction rate of Version 2. Constraints on construction and launch rate are so low that many thousands of ships could be launched every window. Construction rates could climb into the hundreds per year in a single factory. Ticket revenue could fund this, if a positive margin on launch business was maintained.
• Faster ships that can launch multiple times in longer launch windows. This requires better engines and better mass ratios, but eventually there could be cargo and people arriving year round.
• Entry of other companies and agencies into the bargain. Could achieve 10x, possibly 100x on rate.

On the flip side, I think it's likely that the minimum viable population requirement will shrink to the point that even small outposts will have the ability to reach full autarky.

Project Timeline

Mars 2020 - Aquifer search probes land, Version 0 ships performing atmospheric tests on Earth.

Mars 2026 - First 10 crew arrive, 3 ships on surface. They scale propellant plant, assemble a lot of base for new arrivals.

Mars 2030 - Middle of explosive growth phase, base population grows to near 1000. Pilots for all primary industries established.

Mars 2035 - First private and 10,000th settler arrives. Mars spaceport hosts dozens of Version 1 ships and the Version 2 prototype, looming over the rest.

Mars 2043 - Ticket prices fall below $100k and the population exceeds 100k. All secondary industries at least in pilot phase. "Mission accomplished"

Mars 2050 - Population on Mars exceeds a million. Dozens of outposts formed.

Mars 2060 - A web of towns and cities all over Mars, with the first base and by far the largest forming a sort of hub.

How To Fund Space Settlement - Where Does The Money Come From?

Regular readers will know of my enthusiasm for the settlement of humans in space. Last year, I wrote a book (caseyhandmer.com/home/mars) about unsolved technical problems connected to Mars. Here I'm going to take a slightly different tack and talk about the financial question. In a previous post (http://caseyexaustralia.blogspot.com/2017/05/a-roadmap-to-industrially-self.html) I talked about launch cadence and shipping for industrialization of Mars on a rapid timescale. This discussion is oriented towards that problem, but I hope will be general enough to be useful for any other potential destination, including the Moon, asteroids, deep space, low Earth orbit, or beyond.

Aspects of this discussion often take on a religious tone. Here, my only goal is to explicate various options and perhaps list the strengths and weaknesses of each proposal - certainly no single approach is adequate to the task. It is clear that this is a problem that can consume extremely large sums of money!

How much exactly? It is difficult to know for sure. Using the industrialization text as a start, I propose that a population of 10,000 people can be reached on Mars in 20 years with a steadily growing launch cadence, requiring the construction of a new giant rocket every year, with re-use gradually becoming more widespread. The construction of this vehicle, plus tech for the ground, could run into the billions of dollars per year. Therefore I will baseline assumptions that a Mars settlement program will require billions, but perhaps not many tens of billions, per year for the indefinite future. This sounds like a lot of money. This isn't the place to justify expenditure of huge quantities of treasure on a project that will benefit practically no-one alive today, and maybe no-one ever. I will state merely that it is of the order of NASA's current budget, or slightly less than the cost of air conditioning in military bases in Afghanistan. It is also comparable to national expenditure on cosmetics, or a medium scale infrastructure project such as maintaining the interstate system.

In the following I have split various proposals into a few subheadings, but there is substantial crossover.

Finance

Broadly speaking, finance-backed concepts draw on the only limitless resource on Earth - human greed - and try to provide a mechanism for a big payday down the road. Generally speaking, any Mars-related investment could probably get better returns in less time on any other project on Earth. In particular, most very wealthy people don't have 50 years to wait for their money to grow! This is the primary obstacle to finance-based funding methods. Nevertheless, the quantities of money being spent, and the outrageous scarcity of certain key resources along the way, make for many business opportunities with shorter timescales for ROI. No-one doubts that settlement of space won't make a lot of people very wealthy, but the overall source of wealth is another question entirely!

- Value capture. As space transport tech improves (as it must), the value of assets in space increases disproportionately. It is possible to hedge this increase in value by, say, buying options on likely sources of key resources on Mars and holding the paper until someone needs to buy it. The primary weakness of this approach is that ownership of resources in space may be very hard to enforce, and existing legal frameworks are still very underdeveloped. Certain strategic materials or manufacturing know how on Earth has already proven to be a good bet.

- Arbitrage. Similar to value capture. Find a way of pricing some asset that has a lot of uncertainty in its future valuation, or is significantly undervalued in the market, and place a bet. Financial instruments surrounding insurance were key components of both the Dutch East India company and the 2008 financial crash. There's plenty of money available if one can figure out how to direct it.

- Triangle trade. This will be useful down the track, where Mars will be the obvious staging post for asteroid mining in the main belt, if there's ever a need for that. The Mars settlement has to get to a certain size before this is possible.

- Media rights. It may be possible to control the flow of information to and from Mars well enough that selling the media rights provides enough capital to keep the program going. This was the idea behind Mars One, and I doubt it would produce enough revenue, at least after all the middle men on Earth have taken their cut.

- Blockchain. Never say never. A Mars currency ICO? Or space-resource backed currencies more generally? I can imagine blockchain-based technologies becoming part of a collaborative design and manufacturing effort, but I doubt there are enough users and buyers of crypto currency to provide the steady stream of money needed.

Philanthropic

There is a long history of philanthropic space exploration. Indeed, since the invention of the telescope by Galileo, nearly all major telescopes have been funded by wealthy donors of one sort or another. Why? There's an industry devoted to discovering ways to get the rich to part with their money, but many of the 19th century industrialists who funded the famous instruments of Southern California wanted to contribute a positive legacy.

- There are people who are so rich they have nothing to spend their money on but more money. Or a space program! At the most basic level, if each California billionaire bought the naming rights to one big rocket for a billion dollars, the problem would be largely solved. Who doesn't want to name a gigantic rocket in honor of Steve Jobs?

- Crowd funding. Relatively small contributions by some large number of people can raise stupendous sums of money, as the IRS has shown.

- At a more general level, space tourism could be a source of revenue, much as a handful of enthusiasts can get flown to the south pole or space station for absurd sums of money. The only other way to go is to be a professional, and that's more time consuming! I think the number of people who can afford to go to Mars and want to go will be quite small for quite a while though.

- There are companies with enormous and partially idle engineering resources. Caterpillar, AECOM, and numerous others have the technical might to solve corners of the problem without breaking a sweat. But why would they? It could help them compete for talent, provide prestige, training, brand development, or could form part of an incentives package with policy support.

Open Source/Volunteer/Collaborative Venture

This approach is very underdeveloped. Part of funding the space program is about finding ways to make it cheaper. There are tens of thousands of qualified engineers out there who could contribute their time after hours, if only there was a mechanism, platform, or more precisely, a protocol to form the method of exchange. While few in number, there are some prominent success stories borne of this approach, including the Linux kernel and open source software more generally. Applying OSS/Agile/SWE techniques to hardware engineering is an area of active experimentation. But finding a way to tie together any program that must involve more engineers than can fit in a meeting with something better than the status quo - reams of paper - is a goldmine in itself. If a hardware-oriented project management mechanism became the defacto standard, like git etc. has in software, then this provides an additional incentive for large companies to contribute resources to the problem.

Policy/Government

Policy or law is the biggest stick with which to hit this problem by far. It's also the hardest to motivate, though perhaps a first move from a private company could see multiple governments reactively entering the space.

- Revision of the outer space treaty can enable a land grab or resource race. There are precedents for the governing body to issue resource or access licenses preferentially based on contributions to the central task. Either way, there needs to be well developed mechanisms for ownership, disposition of risk, dispute resolution, and evolution of the standards as new problems manifest.

- Jobs program. Just spend a whole lot of money in key districts and states. Not the best way to minimize costs, but probably the best way to mobilize public money.

- Social movement. Oriented towards planetary defense or fear of losing ground to a rival nation.

- Restructuring of defense budget. This is the biggest slice of the pie by far, and most of the same companies would be making the money. Would require a broad consensus, so hard to do in a proactive way.

- Bailout/rescue of failing private mission. Perhaps private space development needs additional investment to rescue the sector or safeguard strategically important technology. There is a precedent for this in the resurgence of the Russian space program in the 1990s due to strategic foreign investment.

Industrial capture

Many of the above approaches place a lot of control or uncertainty beyond the realm where it can be definitively controlled. A more direct method is to directly create wealth and then use it for whatever you want, as long as that is space settlement. At its core, all wealth is created the same way. Create demand, then control supply. The more of each, the better. Creation of whole new classes of things to own, or whole new markets, are surefire ways to create the opportunity for fabulous wealth.

- Technology. Invent a magic widget everyone wants. Or find a way of generating something (eg energy) more cheaply. Defend the IP. Bank the difference.

- Capture an industry. Is there a big industry out there with lots of revenue, lots of profit, and low competitiveness? Time to disrupt. SpaceX seems to be making a play towards satellite internet (a whole blog post in itself) and large infrastructure projects. The Boring Company seems poised to exploit a lot of latent demand for reduced travel time in congested cities.

- Space mining/resource exploitation. If it was possible to mine certain strategic resources in space and find a market for them, then an industry devoted to that could be financed or bootstrap. The main obstacle to this concept is the sheer cost of doing anything in space. It may even be cheaper to supply the moon with anything it needs from Earth, rather than to obtain it locally. Mars will need local resources, but it's hard to imagine something valuable enough to be worth shipping all the way back to Earth, except passengers and functional spaceships.

Exotic/Enabling tech

One way to reduce the required sums of money dramatically is with advanced or even exotic technology. I'll rank these roughly by level of plausibility.

- Re-usability and in situ resource utilization. This alone can reduce current costs by a factor of 100 or more.

- Space power. There is probably no way to make money selling space-based solar power to the ground, but space nuclear reactors for use on Mars or gigantic mirrors for terraforming are an interesting concept.

- In space manufacturing. One driver of space costs is launch costs. Launch a factory once and make everything in space (from asteroids, say) and that problem can go away. It's not clear to me what the critical size of this industry is, but I'd estimate somewhere north of a million tonnes produced per year before launching from Earth becomes bottlenecked somehow. Note that self-replicating robots lower costs on Earth too!

- Advanced propulsion. Anywhere from nuclear thermal rockets to warp drive. There's no reason why such concepts can't be developed in parallel with existing methods, but I don't think it's a good reason to wait.

- Life extension. Perhaps during my lifetime we'll solve aging and humans, freed from their four score and ten will think about problems on a longer time scale. I think life extension is probably key to very long space voyages, and may unlock ways to avoid possible space-related illnesses. But I'm not holding my breath.

Conclusion

What do you think? Which of these sources will prove to be the most enabling?

Honeymoon

After our wedding (blogged by C at https://medium.com/@corbett/aotearoaconf-2017-aka-christine-and-casey-got-married-d4640fdc3569), C and I went on an eclipse-themed honeymoon! 

Photos - https://photos.app.goo.gl/W0QVA6Fwp8gQ6x9n2

Twitter honeymoon coverage - https://twitter.com/search?f=tweets&vertical=default&q=%23astrohoneymoon&src=typd 

One doesn't always get the chance to take a week of holiday, so we had grand plans. We had already driven Space Car up to the bay area, so after finishing up at the NASA Frontier Development Lab, I hit the road and got stuck in awful traffic and searing heat for nearly four hours. 

But I persisted and eventually made it to Davis, where I met C (just done with a public policy event at Sacramento) and another friend S. After a hearty dinner, we drove east, and a pigeon tried unsuccessfully to land on our car. We didn't stop, but shot up the Donner Pass and found the sketchiest hotel in all of Reno. We insisted on changing out of a room with multiple blood stains on the lamp shades (of all places!) to one with plastic bags over the smoke detectors. 

The next morning we left Reno in great haste and drove east, stopping outside Tesla's Gigafactory for breakfast. The road took us east and north past Winnemucca to, eventually, Boise. Boise has a bizarre hotel with themed suites, and we stayed in the Sleeping Beauty room. It had a castle, suit of armor, waterfall and large bathtub, and the bedroom was inside a cylindrical tower. We explored the city and had a dinner so late (8pm) that I fell asleep on the plate.

The next day we drove a few more miles north west to Ontario, just over the Snake River in Oregon. We started to run into people who looked like they might be eclipse hunting, with telescopes, filters, and themed teeshirts. We did some eclipse spotting location testing, but mostly found a series of depressing towns around Weiser. Back in town we checked into a hotel, met our friend M who had flown into the airport, and eventually found a terrific Mexican restaurant behind the truck stop behind the other truck stop, where everything was cooked in lard. As it should be! 

Migrants on the Oregon Trail would travel down Snake River to Farewell Bend, the last place to die a good death before traversing hundreds of miles of deserts to the west. Today, it's a lovely state park and on this day it was full of cars and people all set to have themselves a wonderful time. 

We arrived at Farewell Bend about an hour before first contact, and the place was very busy. We parked Space Car about a mile up the road, loaded up with gear (inflatable couch, binoculars, filters, camera, camp food and cooking equipment, sunglasses, hats, water, drone) and walked in. We found a patch of lush grass between widely spaced trees (for shade) and got settled. A nearby viewer introduced himself as a 60s era Caltech alum working on cold fusion, and a few dozen yards down the hill were a bunch of amateur astronomers with all kinds of telescopes and fancy filters.

Farewell Bend is the place where people on the Oregon Trail left Snake River to cross the desert to the west, and to this day it has a great outlook over the river and some mostly barren hills opposite. The sun was high, and the sky was totally cloudless. We got our gear in order and settled in. I ran into another more recent Caltech alum by a line of suspiciously neat porta-potties. 

At every point during the event the crowds' collective murmurs kept us informed as to what was going on. Christine and I wore shirts with variations on "scientist! ask me anything" written on them, but everyone we talked to seemed to know more than we did. Later, someone said it was their 12th eclipse and not as good as the one last year!

Around 10:20am first contact occurred, when our filtered binoculars showed the edge of the moon touching the edge of the sun. The moon progressed toward the lower left, over the next 70 minutes covering more and more of the sun until, with just minutes before totality, the light got noticeably darker, the colours stood out like an overly-processed photograph, and shadows got sharper. Dappled shade behind trees was a total mess of overlapping crescents - the splotches of light in the shade of trees are, afterall, slightly defocused images of the sun.

A minute before totality, the area of the sun was so reduced that ripples in the atmosphere bent the light coherently enough to get shadow bands, rushing streaks of black and white like the bottom of a pool. It was as though, in the last rapid fading of the day's light, the light itself was breaking into shards. 

The opposite sky darkened and the moon's shadow rushed towards us at the speed of the fastest military planes and, with the last diamond of the sun extinguished, the sky became totally black. Venus, Mars, and Mercury were all visible. The horizon was sunset colours in 360 degrees. The sun was now an inky black disk, like a hole in the sky, with the light coloured streaks of the solar corona shooting out from both sides, like a mustachioed devil. Through unfiltered binoculars we could see two solar prominences in vivid pinkish purple at about 2 o'clock and 5 o'clock on the face of the sun. 

Despite promises, birds didn't go nuts (though I saw this in an annular eclipse a few years back), but a few dogs and children lost their minds. 

Two minutes felt like two seconds, and the sun peeped out from the other side. The moon's shadow rushed away up the opposite hills, the sky steadily lightened, shadows returned and then began to gradually blur once more, though tree shadows looked weird for much of the next hour. By 12:44pm it was all over. We ate some lunch, crashed a toy drone 4000 times (learning!) and eventually drove out via some amazing windmills. Traffic was pretty reasonable - nothing like the horror we were yet to encounter in Yellowstone.

We returned to the crazy Boise hotel and this time stayed in the Treasure Island suite, themed as a sailing ship with a crows nest, plank, beach, and coconut palm shower. We found a local place with a secret vegan menu, did some work, and then passed out. Solar eclipses are amazing. I highly recommend them!

The next day we headed further east, stopping at the incredible lava fields of Craters of the Moon National Monument (also full of people), and hiking through a huge lava tube. We had a freeze-dried risotto for lunch, then drove on to Jackson in Wyoming, which contained numerous examples of extreme mediocrity for extreme expense. But was rather pretty for all that.

The next day we drove north to Yellowstone National Park, where we spent 2 hours in crawling traffic because a 3 mile section of road was reduced to one lane - but eventually made it to the geyser fields, which were pretty good. I have seen the geysers in New Zealand and Kamchatka, so I suppose the next stop is Iceland? We walked around all of them, watched Old Faithful do its thing, and eventually drove north and west out of the park, enduring only 10 more miles of stop-go traffic, and nearly running out of gas. Once back in Montana and Idaho, we stepped on the gas, getting dinner at Olive Garden (at least a pound of pasta) and staying the night in Pocatello. 

The next day we drove south once more into Utah and got lunch in Salt Lake City. We listened to Book of Mormon to celebrate, then visited the library and the Grand American Hotel, which was staggeringly overdone. We had orange juice while a harp played! We left town, following wind turbines through a gap in the mountains to the east of the city and, after only the usual two or three hours at blazing speed, arrived at Canyonlands National Park in time for sunset, which was pretty fun. On the way out, we saw a fox and some deer, then spent the night at hotel in Moab. 

Next morning we got underway early, visiting the busy and hot Arches National Park, which contained people, hundreds of stone arches, and balancing rocks, then cut west across rural Utah along the most mindbending Interstate (I70) I'd ever seen, eventually arriving at Bryce Canyon. C had never heard of it before so I got a picture of her face when she got to the edge of the cliff. We didn't have time to dispatch a long hike, so we headed on past Mt Carmel Junction to Zion, enjoying the tunnel and staying in the lodge, eating at the grill, and generally living the life. Once again we saw the Milky Way and some deer before bed.

The next day we offset some of our enforced idleness by waking as early as 7 (!) and quickly strolling up Angel's Landing, a spectacular viewpoint looking out over the whole of Zion Canyon, accessed by a perilously narrow (4' wide) ridge with a 1000 feet drop on both sides. We followed that with a nice walk up The Narrows, took in lunch at the grill, drove back to the I15, down the Virgin River Canyon, then stopped in at Valley of Fire State Park. The Mormons also traveled through here, but I just love the red rocks, bluish plants, prehistoric carvings, animal tracks, dinosaur tracks, and weird shapes. 

Heading south we also stopped at Hyperloop One's test track by Apex Parkway, where I pointed out to C what parts I'd designed. The most obvious feature is the subtle curve of the tube following the landscape, though the original design was 12x as long! Finally we got into Vegas, eventually managed to check in at the Rio (I wouldn't go back...), took in the Carnival World Buffet, the Penn and Teller magic show, then went to sleep. 

The next day we flew the drone around the room, had a $50 room service breakfast (stale cornflakes), checked out, then drove back to LA via the Baker Thermometer and the Victorville Whiskey Barrel, another establishment with a secret vegan menu. The Cajon pass on the 15 down to the LA basin is one of the scariest roads I've ever driven, but soon enough we were back in LA, exhausted but happy to be home.

And that is how we conducted our #astrohoneymoon.