The Space Review

Lunar base
Done correcly, lunar transport costs can be brought down low enough to even make adventure tourism viable. (credit: NASA)

A lunar vision at $2,000/kg

The current issue of The American Enterprise is titled “Look Heavenward?” It takes a hard look at space motivations and find them wanting. William Tucker’s piece, “The Sober Realities of Manned Space Flight” makes some tough critiques of the space program past, present and future. So is the future golden or leaden?

There are some unreasonable criticisms in the piece. It repeats a bogus price tag for exploring Mars: the $500-billion number deconstructed by Dwayne Day back in March (see “Whispers in the echo chamber”, The Space Review, March 22, 2004). While not endorsing the $500-billion number, Tucker strongly criticizes lower numbers. I think a $10-billion prize would do the job nicely with zero risk to the taxpayer of overruns.

Tucker also said that, “It was more than a century before Columbus’s discoveries led to any attempts to colonize the New World.” It’s true that it was over a century before the English colonized North America after Columbus’s discovery of North America. But the Spanish colonized North America less than 20 years after Columbus’s discovery and the Caribbean in the same decade as the discovery.

I concur with him that the scientific justification of Moon and Mars missions do not really support the cost of the missions.

Tucker finally notes that 16th century Spain “bankrupted itself in pursuing the Age of Discovery.” Tucker is omitting the part about ships filled with American gold and silver filling the coffers of the Spanish. I would take the roller coaster ride of rags-to-riches-to-rags over the slow-turtle rags-to-rags-to-riches English approach to colonization, but that’s just me.

I concur with him that the scientific justification of Moon and Mars missions do not really support the cost of the missions. The money spent on the space shuttle and ISS could probably be redeployed to better uses. Two uses that Gregg Easterbrook suggests are nuclear propulsion and a search and destroy mission for asteroids and comets with our name on them. These are a good start.

Both Easterbrook and Tucker nominate lunar colonization and reject it. Easterbrook says:

A research base on the moon? Surely moon researchers would discover many things about the origins of the solar system that would be of interest to geologists. Maybe they’d make some stunning finding like the wreckage of an alien space probe. But would anyone like to bet?
Given that today’s nobody-knows-what-it’s-for Space Station has already cost up to $80 billion, a manned base on the moon, farther away and requiring extra descent and ascent energy, might cost at least three times as much. Odds are the yield in human knowledge would be small compared to, say, spending the same amount on medical research. And please don’t tell me we would mine the moon’s resources. Almost all primary commodities are already in oversupply on Earth, while no one mines Antarctica, though that’s possible at a minute fraction of the cost of moon mining.

Gold and other commodities are not in oversupply—supply and demand are always in balance. Gold still costs $20,000 per kilogram and platinum $30,000/kg. Dennis Wingo makes a case that it will be easier to find platinum group metals on the Moon than in Antarctica. The trip from the Moon to Earth is mostly downhill. If smelting can take place on the Moon, transportation costs are not prohibitive even without the use of lunar oxygen. Of course, carting up some prospectors, a smelter, and a truck, as well as figuring out a way to make it all work under extreme conditions, makes the project tenuous.

There is an alternate compelling vision: one of colonization by space adventurers.

An estimate of $2,000/kg round trip from the Earth to the Moon is not so far fetched, given that much of that is to get to Earth orbit. SpaceX is quoting $15.8 million for 5,450 kilograms to the ISS or $2,900/kg. That corresponds roughly to $15,000/kg to the lunar surface. With regular service like airlines in the form of reusable rockets, we might expect the cost of the service to drop to about triple the fuel cost. A Falcon 5 hefts about 170,000 kilograms of propellant for a mass fraction of about 94%. With NASA paying about $0.20/kg for oxygen and the price of jet fuel at around $0.70/kg, and with a mix ratio of 2.5-to-1 oxidizer-to-fuel, that would give us about $35,000 for fuel and $25,000 for oxygen. So if the goal is $180,000 to orbit for a Falcon 5-class launcher, or $33/kg, then maybe $165/kg to the Moon is feasible. $2,000/kg is a bit more than the geometric mean between $165/kg and $15,000/kg. That might enable visitors at least even if the prospectors stay home.

Tucker says that visitors won’t find much:

The moon is not a virgin continent waiting to be inhabited, but a barren oxygen-less desert that will have to be claimed inch by inch. At best, it will require the construction of huge, closed-in Earth-like environments that would have to be provisioned continuously.

There is an alternate compelling vision: one of colonization by space adventurers. There is, in fact, tons of oxygen waiting to be cracked out of the lunar regolith. If there is water at the poles, there will be one fewer resource to bring and rocket fuel can be cracked on site. Even if only hydrogen is shipped from Earth, lunar oxygen makes rocket fuel and topping off the water recycler much cheaper on the Moon than if oxygen had to be shipped up.

A “closed-in Earth-like environment” reminds me of walking from building to building on the second floor when it is snowing in Boston. The facilities would not be too much different from malls besides being airtight. The customizations required for Moon living would be on the same order as the cost of porting the material at $2,000/kg. Suppose it costs another $2,000/kg.

I think the typical space adventurer could spend a wonderful time in one-sixth g for a couple weeks with only a few hundred kilos of consumables imported from Earth. Bancroft and Arnesen carried only 100 kilograms of gear for their 100-day expedition to Antarctica. In situ oxygen and recycling or local production of water make that level of consumption luxurious. The durables could then be reused by other adventurers. Two thousand kilograms of durable gear could make the lunar glass air tight and compelling architecturally. Custom furniture ought to do nicely. That’s nothing if it gets used by 500 adventurers before it wears out. They promise not to sit too heavily on the chairs.

If net consumption could be kept down to 100 kilograms of consumables a year, that would be maybe $500,000 a year to stay on site, competitive with oilrigs.

So picking up the calculation again, if we have regular tourist service at $2,000/kg delivered to the surface, we might expect a few hundred kilograms of ship and a few hundred kilograms of supplies to arrive with each adventurer. Suppose it ends up being 1,000 kg. I think we would see a pretty good demand at $2 million each for a two-week stay on the Moon. With Futron predicting a demand of 60 folks to orbit at $5 million each in 2021, I think we might see accommodations for eight filled nicely at $2 million each for a two-week stay. If you double the price of the flight, you can still keep the price at $1 million per week by requiring a minimum four-week stay. It would give “lunar month” a whole new meaning. $400-800 million a year in revenue won’t support an $80-billion manned base on a commercial basis, but it certainly could defray the operating cost of a mixed-use station.

The lunar immigrant would need to live a more austere existence to keep the kilograms down. If net consumption could be kept down to 100 kilograms of consumables a year, that would be maybe $500,000 a year to stay on site since cargo does not need as much in the way of life support during transit. That price sounds competitive with oilrigs. I think maybe the tourists will be served by locals. Perhaps they can pan for gold in their spare time.



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