Fuel & Tunnels

My wife says I should try to meet Elon Musk. Riiiiight. Her reasoning: I seem to think like him, in the sense that I notice what seems to me overwhelmingly obvious things that, for whatever reason, completely escape the notice of almost everybody else. This ignores the difference in native intelligence – I’m a pretty smart guy, but not in Mr. Musk’s league – and, most important, work ethic – I can and have happily whiled away hours and days at a time without achieving what Musk gets done before breakfast on a bad day. Having known people like that, the kind of people who rest by thinking about solutions to some other problem, I get tired just thinking about it.

Couple cases in point: For decades, my longsuffering spouse has heard me rant about how solar is largely meaningless without vast improvements in storage: until you can save the power on nice sunny days for use at night and on cloudy days, we (collectively) still need traditional power generation capacity at or near current levels. All solar would do is allow us to throttle down on occasion.

Musk founds Tesla and buys SolarCity, in order to develop adequate battery storage systems for meaningful solar power systems.

For decades, my wife has heard me speculate on the need for more traffic tunnels. With the advent of tunnel boring machines, which not only dig the tunnel, but install steel-reinforced concrete liners at the same time, scale and improved efficiencies should enable more and more traffic problems to be addressed by cutting more direct routes that simply go under or through obstacles.

There was a period of half a year when I commuted from a rural area nestled against Mt. Diablo, from where it took about a 10 minute drive to get into civilization. Then, from civilization, the 5 mile drive to work took over half an hour. I had to take a route that is one of only three ways to get from the bedroom communities along the Bay and Delta down to the freeways that take you to Silicon Valley. So, at 7:30 in the morning, lines of traffic traced back over the hills, which then had to merge with other traffic and head down surface streets for about 7 miles to get to the freeway.

A direct route would run smack into Mt. Diablo. Actual routes skirted the mountain, or otherwise went miles out of the way. I would regularly say to my wife: if you threw 6 lanes worth of tunnels through Mt. Diablo from the Delta to San Ramon on the 680, all this traffic could get where they’re going without having to flood the surface streets, making my 10 minute local drive take 45 minutes.

Musk founds the Boring Company.

TMI, but it does show modern tunnel boring machines in action

I’ve long discounted space travel. The economics simply don’t add up. One way to think of the problem: best case (SpaceX’s Starship and Super-heavy booster) it takes about 45 tons of fuel on the ground to put one ton of fuel into low earth orbit. So, if you want to go somewhere, Mars, say, you’ll need 45 times as much fuel to get to the starting line (low earth orbit) as it will take you get to and return from Mars.

Which is a lot of fuel. The Super-heavy booster holds 3,000 tons of fuel, and burns effectively all of it to get Starship 100 miles up. Starship then burns almost all its fuel to get the rest of the way into orbit – with only a max of 150 tons of cargo. You’d need something like 1,000 tons of fuel to get Starship to Mars from low earth orbit – and that’s just a 1-way ticket.

So, to go to Mars using the most efficient and practical methods now in development, you need to launch your spaceship into low earth orbit, then launch about 1/2 a dozen more refueling ships, each burning about 5,000 tons of fuel to get enough fuel to your orbiting Mars bound ship to get it to Mars – but not enough to get it back to earth.

On the plus side, fuel is (relatively) cheap. Haven’t heard yet how they plan to keep the fuel – methane and liquid oxygen – supercooled and liquid while all this refueling is going on, but that’s an engineering problem. The hammer I have is economics (if I wanted an academic title for my expertise, I’d be an Applied Microeconometrician) and so I’ll bang on the economics of the thing.

The challenge is daunting: first, you must fund the development of the tech; then, fund its deployment; then fund its ongoing operation. If the goal is building a self-sustaining settlement on Mars, I cannot imagine how the economics could possibly support that. You’d spend a trillion dollars to get a 1,000 people on Mars, huddled inside probably underground habitats, doing – what, exactly? Mining feedstock for a methane and LOX plant so that they can go home? And? “Outside” is no more hospitable than the surface of the moon. There’s nothing on Mars worth anything like what it would take to get it and send it back to earth….

Musk becomes a billionaire so that he can fund the initial development out of pocket. He comes up with StarLink, a broadband from anyplace on earth system that, it turns out, should generate billions in revenues per year – and is deployed using the rockets he’s developed. He comes up with a series of uses for Starship, each of which has potential revenue streams attached to it: bulk LEO lifter, moon lander, super high speed point to point transport, each with subspecialties under them. If even a few of these things work out, SpaceX will have the revenue streams needed to build a fleet of Starships, without any being attached to a Mars colony.

Well? Could it work? My gut level analysis is: No. A Mars colony would have to be a massive, nation or planetary level, vanity project. Economically, it does not now make sense. The complexity and risk, not to mention expense, associated with refueling LEO spaceships from earth for interplanetary travel looks prohibitive. The chances for any profits from space are fanciful. (The idea that you’ll just go snag asteroids rich in rare elements is – optimistic.)

But…. What if you could refuel from space? The moon has water, it is said, from which methane/LOX can be made. Getting fuel from the moon to orbit is vastly easier. Better yet, there are comets made up of the needed feedstocks…. All you have to do is lasso one….

Or maybe Venus? Drop a factory into orbit, scoop up (somehow) some of that sweet CO2 atmosphere, and boom! (figuratively! I hope!) you’re ready to go.

Best of all, invent Hobartium – that’s the room-temp superconductor from Mike Flynn’s Firestar series – and unfurl the mag sails!

Surprising breakthroughs are made, so this isn’t totally a fantasy. But for now, it’s fuel from earth – and that’s not a pretty sight.

My wife imagines me having this chat with Elon Musk. I imagine he’s thought of all this and more. It would be fun. Not sure what the point would be . Evidently, he likes to hire people who dream big and execute. I’m half-way there!

Author: Joseph Moore

Enough with the smarty-pants Dante quote. Just some opinionated blogger dude.

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