"We went to the Moon as technicians; we returned as humanitarians." --Edgar Mitchell

"We came all this way to explore the moon, and the most important thing is that we discovered the earth." --William Anders

Wednesday, January 30, 2013

Let's Go To The Moon!

"The fundamental limitation to expansion into the solar system is not technological, but economic." - James R. Wertz

To bring everyone up to speed: I read an article called "Architecture for Developing an Economically Viable International, Large-Scale Lunar Colony" by James R. Wertz about a week and a half ago, and I've been picking at my response to it ever since. It's mostly that I've not had a whole lot of time to devote to writing something that is solely for my own pleasure.

When reading this article, I had quite a few moments where my engineer mind gave a snort and said "that's a stretch!" However, my biggest sticking point was not ultimately at the core of his argument. More or less, Wertz was saying that the most dramatic reduction in cost would be obtained not by reducing launch costs to a small fraction of what they were at the time this article was written (1999), but by fully utilizing COTS (commercial off-the-shelf) technologies and not sending up more hardware than was needed. This struck me as a similar to the strategy that Robert Zubrin outlines in his book The Case For Mars (which I haven't entirely read yet, so no spoilers, plox): utilize as many resources as possible in situ. This means using the regolith on the Moon as building materials for everything from habitats to chairs and desks, as well as finding non-terrestrial sources of nitrogen and other gases. When coupled with using as much COTS tech as possible, establishing a 1000-person colony goes from costing trillions of dollars to mere tens of billions. Wertz makes the bold claim that it would cost less than the ISS. Let that sink in for a minute before I dive into some of the nitty-gritty.

Has his claim sunk it well enough, now? Alright, moving on.

I want to talk about his treatment of the problem of launch vehicle costs, first, as it's probably the most visible aspect of almost any space mission. Wertz never says exactly what the average cost of launching a kilogram into LEO (Low-Earth Orbit) is in 1999, but I'm going to go out on a limb and say that it's pretty much the same as it is today (ignore SpaceX for a moment, I'm getting there). Well, this guy builds in as a major assumption that launch costs are going to drop by a FACTOR OF 50 in the indeterminate future. This factor of 50 includes what is essentially a bulk-rate discount, bringing the target cost of getting mass to the moon down to $1600/kg. That sounds like a lot, especially when you consider that the average person weighs about 75 kilograms (no, I don't have a source for that; I'm pretty much making it up). It's definitely out of my budget! Let's take out the factor of 5 that was taken into account for launching a lot of mass to the moon. This causes the cost to bump up to $8000/kg. However, let's look at SpaceX, now. If you go by their website (which doesn't have cost per kg, but rather has cost and weight separately - I did the math), then the absolute lowest price to get a kilogram of whatever to Geostationary Transfer Orbit (GTO) is .... *drumroll*

*opens envelope*


And that's about half of what any other launch vehicle can do right now. (I almost wrote lunch vehicle, and now I'm hungry) It's not even to a lunar transfer orbit! And Wertz included a list of companies and the corresponding vehicles that were trying to hit the factor of 10 reduction that was needed in the first place, all of which are no longer being actively developed. This list includes the X-33, which makes me sad because that vehicle had a Cool Factor of over 9000.

But, as Wertz explains, this launch cost in conjunction with the "traditional" cost model for lunar colonization (if anything concerning what we've never done before can be considered tradtitional) is only going to get the development cost down to a figure that is in excess of $5 TRILLION. That's a T, ladies and gentlemen. That's still a humongous number. This is actually largely because projects like lunar colonization are usually approached as design solutions looking for a problem. Everything is specifically engineered for that environment, without specifying exactly what the requirements are for a lunar colony. If something doesn't need to be extensively engineered, it shouldn't be, was basically his point. The trick is figuring out what needs to be engineered, and what can and can't survive the harsh lunar environment. A smartphone, for instance, might not be able to survive the radiation as well as, say, a power drill.

So more or less, this article emphasizes Systems Engineering processes to bring the cost of engineering projects like this down. Just as SE has to be modified for Small Sats, it would also need to be modified for something like high-capacity colonies. And it all comes down to defining the requirements adequately without predetermining a design solution.

There were some other interesting tidbits in here, a lot of them about where the colony would get its air (he proposes bringing some of it from one of the gas giants - isn't that getting a bit ahead of itself) and other resources and minerals that aren't readily available on the lunar surface.

What I got from this, though? Wertz is totally Alt Space.

Anyone reading? If you got this far, AND you read the article (or part of it), let me know what you think of his proposals in the comments!

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