Tuesday, August 30, 2005


Yesterday on KQED's Forum program Michael Krasny hosted a panel talking about Graffiti in San Francisco. I thought a lot of these folks were talking around the right idea without nailing it.

One panelist had previously been a graffiti artist and was now a professor of Chicano studies. He thought we needed to engage the kids more (I thought, yep), give them avenues to express themselves (uh oh). Then he got off on a diatribe about how our culture oppresses these kids, is private property really moral, that sort of thing. Michael cut him off and he didn't go there again. It's a shame. I think the issue of private property is the right one. Kids join gangs to get power. Gangs are tribes. We want to belong to tribes.

Most of us, especially teenage boys, want to find our place in the world. We want to assert control. We want to find out who we boss around, and who we are going to have to obey.

Prehistorically, we joined tribes to gain power. A small tribe can have a readily understood structure, so you can figure out how to improve your position in the tribe. Then you can improve the tribe's wealth by asserting ownership of the environment. If that stuff is currently owned by someone else, you steal it. Sometimes this involves tribal warfare, like going to a nearby tribe and killing all the men and boys there (drive-by shootings). This take-and-take-back is what establishes tribal boundaries. It appears to have worked well enough in the past with Amazon-jungle-like population densities.

Here we are in the modern world, where this kind of behavior involves unsustainable mass slaughter (e.g. Iraq). Nowadays, there is an awfully big mega-tribe with an unfathomable structure. I'm trying hard to find my place within this mega-tribe. It's not fair, the power structure excludes lots of people who aren't born into the right families.

Lots of those people are trying to find a way around the mega-tribe. The tribe will tolerate some of this behavior. It will absorb some of it, changing the tribe itself, changing the identities of the winners and losers within the tribe. Heck, Open Source is like that, a subversion of the intellectual property regime that has served so many others so well.

But the tribe can't change too fast, or too many tribe members lose out. That's not in our interests. If you want to change the rules on private property, if you want to be a squatter, or a graffiti artist, or (for that matter) a Chinese businessman who sells unlicensed copies of designs originated elsewhere, you'll affect too many comfortable tribe members and we will come down on you, hard.

It seems petty to arrest and jail a ten-year-old tagging the side of a Safeway in San Francisco. One panelist talked about councelling for these kids. Sounds good, but any councelling is going to have to involve waking them up to a set of unpleasant realities, so they can get on with working within the structure of the mega-tribe:

  • They really are oppressed. This condition will not change in their lifetimes.

  • We really will keep sticking them in jail if they try to assert their rights over the ones we unjustly inherited.

  • The system for remedying their situation ("democracy") is malfunctioning badly, and there is very little they can do about it without a lot of thought and selfless action. The latter is not going to improve their personal situation.

  • There is no obvious legal route for them to get rich. If they work hard within the existing system, they can join the middle class, get a mortgage, and become indentured to the international capital system like the rest of us. And they'll be discriminated against the whole way.

    For those of us born to better circumstances, we need a clear-eyed understanding that we can't afford to discriminate against very many other people for very long. Eventually they'll figure out how to organize against the existing structure. We need more of the people of the world, especially those who live closer to me, to have a clearer path to at least some measure of personal fulfillment. Since there isn't enough material wealth to go around, and our media spends at minimum 20 minutes of every hour hammering home the message that unlimited material wealth is a baseline requirement for happiness, it seems to me that the message that our media is sending is opposed to my interests, and those of most owners of private property.

    I doubt I'm the first one to figure this out. Maybe this is why the sons and daughters of the rich have a greater tendency towards philanthropy: it's better to give some of it away than have all of it taken from you.

    And of course, it sure isn't all the media's fault. I just can't think of anything else right now.

    Mood: grumpy.

    Side note: remember to pray for those folks in Louisiana tonight. Maybe when they rebuild New Orleans they can put the whole city on piers, like Venice. Seems more reliable than pumps, and as Venice shows it's quite romantic.
  • Wednesday, August 24, 2005

    Hydrogen from nuclear reactors

    I used to think this was part of the Hydrogen Economy scam. Now I think it might be a good idea, but it appears to be justified to the public as part of the Hydrogen Economy scam.

    Here's the idea: electrolysis of water to make hydrogen is expensive (about $2.46/kg at $.05/kW-hr), because electricity is expensive. But electrolysis at very high temperatures takes much less electricity, since the heat supplies much of the energy. Nuclear reactors can supply that heat cheaply. New gas-cooled high-temperature reactors can supply heat at 850 C. General Atomics has published a report that claims hydrogen could be produced from high-temp reactor steam for $1.53/kg.

    Yawn. In 2003, hydrogen from natural gas cost $1.40/kg. Sounds like a boondoggle for the nuclear industry, combined with some Hydrogen Economy crap that generally makes my skin crawl. Buuut...

  • At May 2005 natural gas prices, hydrogen costs $2.70/kg.

  • The domestic U.S. consumption of hydrogen is huge: about 11 million metric tons per year. Half gets used to make ammonia (fertilizer), the other half is used to hydrocrack heavy hydrocarbons into lighter, fuel-grade stuff. World production of hydrogen is growing at 10% per year. Growth is probably faster in the U.S.

    Bottom line: The U.S. spends $30 billion per year to make hydrogen, most of that is the cost of imported natural gas. The dollar volume is going up very fast as consumption increases and gas prices rise. Billions of dollars a year can be saved by making the stuff at nuclear reactors, and that is billions of dollars directly diverted from importing natural gas.

    Near term future: We're going to need a lot more hydrogen as the hydrocarbon stocks we process for fuel get heavier, for instance, if we start using oil from Canada's Athabasca tar sands. Note that hydrocracking is not a clever way to get ordinary cars to run on hydrogen: Refineries will use the minimum amount of $1.60/kg hydrogen necessary to convert and sell their $0.30/kg crude as gasoline for $1.50/kg.

    I'd think these reactors would be more appealing for their operator than the current offerings. Instead of being stuck with base load electricity prices, they can make electricity during the day, when prices are higher, and make hydrogen at night, when prices fall. It's expensive to store hydrogen, but you can probably store a few day's worth before you pipe it to the refinery down the street. And as long as these reactors are just down the street from oil refineries, there's a good chance the refinery can use some process heat from the reactor, too.

    Finally, there is an international market for any such nuclear reactors, as well as the ammonia that we can produce from them.

    The market seems big enough: hydrogen consumption is growing fast enough that you could build 5 new one-gigawatt reactors each year just to keep up with the growth, assuming each makes hydrogen 24x7.

    So why should the U.S. government subsidize these reactor designs?

  • Macroeconomy: Because a billion dollar subsidy can reduce our balance of trade by $30 billion.

  • National Security: Because it can reduce our dependence on oil (in two ways) by a useful amount, and this is a noticeable step towards energy independence.

    P.S. But none of this means that running cars directly on hydrogen is anything but stupid. It's just too expensive for that. If Governor Schwartzenegger gets a clue maybe he can dump the hydrogen-fueled Hummer and help secure licenses for 6 more 1100 MW units at Diablo Canyon.
  • Tuesday, August 23, 2005


    Nuclear disarmament is a good thing. Reducing the weapons stockpiles in the U.S. and Russia has left both countries with large stockpiles of highly-enriched bomb-grade uranium and plutonium. Every terrorist in the world wants to get some, some terrorists are rich, and some 40-year-old nuclear workers in Russia are living hand-to-mouth. It's a dangerous situation.

    In 1991, Senators Nunn and Lugar had a good idea. The government-owned U.S. Enrichment Corporation (USEC), which operates enrichment facilities in the U.S. to provide fuel for commercial reactors, would buy a portion of Russia's nuclear stockpile so that it could be burned in U.S. commercial reactors. This is a great idea, and a pretty good summary can be found here. There is a snag, however:

    Russia wasn't going to send bomb grade material directly to the U.S., because that would be like actually selling us nuclear weapons. Instead, they mixed the bomb grade stuff with Russian natural uranium, so that the result was 4.4% U-235 -- just right for a commercial reactor. The overall flow of reactor-grade material would have replaced a good chunk of domestic U.S. uranium demand.

    Domestic U.S. uranium suppliers didn't like that. Together, the U.S. and Russia have about 2000 metric tons of bomb-grade material, equivalent to 12 times annual world mine production. By the time the U.S. civilian reactors had burned through Russia's half of this stockpile, the domestic U.S. uranium suppliers would be out of business and Russia would end up being the majority uranium supplier to the U.S.

    So the deal was that Russia would buy the American natural uranium from the miners that was displaced by the Russian imports. This uranium would be stockpiled in the U.S. in USEC's custody. The U.S. goverment got two commercial reactor operators to promise to buy the Russian uranium eventually. Russia would sell the rest off over sufficient time.

    Realistically, it's going to take many decades to work through that stockpile. Now that they've been paid off, the domestic U.S. miners have mostly stopped digging, which will help. Getting this stockpile is yet another good reason to build more nuclear powerplants (though not the strongest, of course).

    The notion of U.S. mining interests delaying such an incredibly important piece of national security work so that they could protect their bottom lines still strikes me as... treasonous. But it appears that negotiators at our government have managed to pay off these people, so that we can get on with the business of paying off Russia for the knives held to our throats.

    Monday, August 22, 2005

    Escape rockets for unmanned satellites

    Re: Is an EELV safe enough to launch people without "man-rating" it first?

    In a May 2003 hearing (before he was head of NASA), Griffin commented “What, precisely, are the precautions that we would take to safeguard a human crew that we would deliberately omit when launching, say, a billion-dollar Mars Exploration Rover (MER) mission? The answer is, of course, ‘none’. While we appropriately value human life very highly, the investment we make in most unmanned missions is quite sufficient to capture our full attention.”

    Since then, he's had a change of heart. NASA's line right now is that man-rating an EELV booster is more expensive than designing a new shuttle-derived vehicle.

    I agree with the change of heart, at least. Unmanned satellites generally don't have reentry and landing systems packaged with them, as manned vehicles must. If a satellite did have a reentry and landing system, for the expensive portion of the satellite, seperately engineered to be fail-safe for other reasons, I suspect the insurance companies would be quite interested in adding escape rockets to the launcher, to recover the billion-dollar-satellite in the case that the $100-million-dollar launcher blows up or simply fails to get it into a reasonable orbit.

    So escape rockets are a good example of something we would deliberately omit from the Mars Exploration Rover. Ironically, the MER does have a reentry and landing system, but one designed to work in the thin atmosphere of Mars. It would have been much different, e.g. heavier and more expensive, if it were also required to get the rover down, safely, into the mid-Atlantic after a failed booster shot.

    Friday, August 19, 2005

    Slime Farms

    The Set America Free folks have the right idea. Their proposal is a series of legislative steps that we can take now that will have the effect of reducing our oil imports through a combination of better fuel efficiency and generation of oil substitutes.

    I'm not 100% in agreement with these folks. They'd still fund hydrogen fuel cell research to the tune of $2 billion over the next 4 years, and they pay lip service to biodiesel research. I'd whack that fuel cell research completely, and put steady money into biodiesel for at least two decades -- $300M/year into biodiesel from crops (this will help work out the bugs in delivering biodiesel through our supply chain and any vehicle use issues), $100M/year into biodiesel from existing microalgae (to develop and debug the infrastructure for growing and processing for millions of tons of algae), and maybe $100M/year to $200M/year into engineered microalgae.

    The oil business is so huge, and leverages such a massive prehistoric biological mechanism, that replacing our oil imports will eventually involve re-engineering our environment in the same way that we have done with building big dams, draining big swamps, and farming the prairie. We are never going to produce meaningful amounts of fuel from farm crops, because there is not enough land, not enough fresh water, and land plants produce too much non-fuel mass to sort through. When Big Oil gets into biodiesel, we'll end up extending Louisiana, Texas, and Florida with dikes extending into the shallows of the Gulf of Mexico. Within those dikes will be massive brackish algae ponds pumped to saturation with the CO2 from coal-fired powerplants. Millions of gallons of oil every day will be extracted from algae separated from those ponds. Environmentalists will be outraged at the devastation wrought on the delicate marine environment. Folks living on those coastlines will protest the change in their views (but will probably welcome the new jobs).

    And negotiations with fundamentalist regimes in the mideast who wish to have nuclear weapons will have a decidedly different tone. Without the U.S. dependent on Iranian and Saudi oil, without their ability to tweak our economy with simple price changes, without the constant flow of Westerners who must tend to their oil fields, without the massive influx of cash that keeps their corrupt governments in power and able to support expensive research into WMDs... things will be vastly different. Conditions will be more like Afghanistan and less like Saudi Arabia. More like Afghanistan but without the subsidized madrasas. But that is their problem, not ours.

    But none of this is possible now because nobody really knows how to grow a lot of algae cheaply, just like nobody knew how to use steam and CO2 injection to profitably leach oil out of a recalcitrant well 100 years ago. It is a U.S. national security priority to develop extensive domestic energy supplies, and that is why the U.S. government should fund biodiesel research. We had a decent program going for about a dozen years, called the "Aquatic Species Program", started during Reagan's tenure, which was canned by the Clinton administration. Here's their report. (300+ pages, check the table of contents and the last couple of sections for the good stuff.)

    So there is a lot of research and development to do.

    I should say that by engineered microalgae, I mean crop development the way it's been traditionally done for thousands of years: grow a lot of algae, select the stuff that produces the most oil, propagate that strain and wipe out the rest. Iterate hundreds or thousands of times. Set up multiple centers across the U.S., so that various strains can be developed independently, optimized for the local environment, adapted to the highly acidic environment we want to grow this stuff in, with different approaches to optimization by different teams. Given the rate at which microalgae grow, I think we should be able to get the iteration time down to a week at maximum. One iteration a day would be significantly better. I'd expect some decent results within a decade. If illiterate people can take wild maize and transform it into corn in a millenium with just one or two crops a year, we can turn wild microalgae into a serious oil producer in a decade.

    I wouldn't hold out much hope for actual genetic engineering of the microalgae. Genetic engineering is good at turning off particular pathways inside cells. It might be useful for adding pathways that wouldn't exist otherwise, say, if you want to produce a particular drug in carefully sterilized bacterial fermenters. But the problem is that any tinkering we do is going to make the resulting species less well adapted to its environment. Algae in the wild live in a very competitive environment. Algae farms are going to be cheap places, not well-controlled places -- we probably can't afford to even put thin plastic film over the ponds to cut down on evaporation and CO2 loss. So we can't protect specially engineered algae from competitors.

    I think there is a lot we can do in the next decade to turn around our crummy national security situation and maybe improve our economy as well. We need to get Congress on board, define the problem, and eliminate distractions.

    Monday, August 08, 2005

    Shuttle replacements

    NASA is mulling two vehicles to replace the Shuttle. Both are based on Shuttle components. This post is really about three things: one, why the proposed NASA designs are about as good as they can do; two, how the proposed designs are worse than the alternatives, and three, what would have to happen for the U.S. to use a better alternative.

    The claimed reason for basing on Shuttle components is reduction of development cost, infrastructure build cost, and time-to-reliability. This last issue is not to be taken lightly -- the flight histories of much of the Shuttle hardware, along with the years of tweaking of that hardware, are irreplaceable. If we're going to launch people on a new rocket, we want to be in a position to say with familiarity that the rocket is safe, and we can only say that about a rocket with a long flight history. Nothing else is going to have a long flight history by 2010. Well, almost nothing, and I'll get to that near my conclusion.

    The other reason for basing the new vehicles on Shuttle components is jobs. The Shuttle program currently employs many tens of thousands of people at NASA and its subcontractors. Those people and their employers want to stay in business, and they have gained quite a bit of leverage on their representatives in Washington.

    Considerations like this are what make NASA's proposed vehicles so sad in comparison to a clean-sheet design. It's not so much that the NASA vehicles are more dangerous or less capable than the alternatives, but that that NASA will do so much less with them than they could do with the alternatives, for the same amount of money. My current favorite clean-sheet design is the one being pursued by SpaceX, and I think it's interesting to compare the two.

    Before I go any further, I should note that unlike NASA and its prime contractors Boeing and Lockheed-Martin, SpaceX hasn't launched any hardware yet (first launch is scheduled for the end of September, 2 months from now). What they do have is 100 or so employees almost all of whom have experience putting stuff in orbit. Assuming SpaceX gets the contract to haul supplies to the International Space Station via their as-yet-unbuilt Falcon V, and assuming they establish regular flights by 2008, they still won't have a long flight history by 2010.

    But back to the comparison. Both NASA and SpaceX are pursuing a two stage to LEO design. Both first stages are reusable (they parachute back into the ocean), both upper stages are expendable, both use capsules to recover the crew and have little ability to return large masses from orbit. All of these are good choices.

    The limitations of the comparison are that the NASA "Stick" design is supposed to lift 20000 kg to the ISS, and the SpaceX Falcon V lifts 5450 kg. So if NASA were to use SpaceX to send people to the ISS, it would have to be three people at a time instead of six, and the capsule would have to be simpler than the full-blown Crew Expeditionary Vehicle they envisage today. Also, SpaceX hasn't yet announced a crew capsule development for the Falcon V. They are going to man-rate the booster, and I think they intend to use it for people after developing a good flight history with cargo.

    Both the SpaceX stages burn liquid oxygen and kerosene. Such engines are well understood, and give predictable, respectable but not spectacular performance. Because the engines are liquid fuelled, they can be throttled and shut down at will. And crucially, kerosene is benign (basically like the gasoline you put in your car) and liquid oxygen is not terribly difficult or expensive to handle. SpaceX uses recently developed materials, manufacturing techniques, and avionics to achieve larger payload per dollar than has historically been possible with this propellant combination. As a result, the SpaceX rocket can be handled by a small team of people and manufactured for small amounts of money.

    NASA's first stage is a stretched version of the solid rocket booster currently used by the Shuttle. That SRB costs about as much to recover, refurbish, and refuel as it does to build a new one, so the reusability is cosmetic. The proposed first stage cannot be shut down early (for instance, if the cabin loses pressure). It cannot be throttled, and the thrust is somewhat unpredictable (which means the whole rocket structure has to be built with more margin to sustain higher peak G and aerodynamic loads, and the upper stage needs more delta-V margin to recover when there is less delivered velocity).

    The SRB is a low performance first stage. It is heavier than the SpaceX hardware: The aluminum-lithium SpaceX booster has a mass fraction of 94%, where the steel SRB has a mass fraction of 85%, and the SpaceX booster has a higher exhaust velocity, 2980 m/s versus the SRB's 2636 m/s (measured at sea level air pressure). The result is that the SRB has to be much bigger per kg of payload as the SpaceX design.

    There is a school of thought in the rocket design community that espouses the Big Dumb Booster. Their point is that a larger rocket is just fine, so long as it costs less. Cost is mostly related to things other than size, like the number of people necessary to build, transport, and launch the rocket. But the Shuttle SRB is so big that its size implies complexity. Pouring single grains of propellant that large requires enormous facilities to mix and cure the components. The entire SRB is too large to pour or transport as a single piece, so it is poured as four pieces, seperately transported to Cape Canaveral, then assembled there. And while the clevis and tang joints between the sections have now been sufficiently engineered to be safe, they impose handling restrictions (NASA cannot leave the Shuttle out in the cold), and cost more money.

    As a result of all this complexity, each Shuttle SRB costs $40M per flight (that's half of the first stage, with no guidance or communication system). A two-stage SpaceX Falcon V sells for $15.9M (that's everything but the capsule on top) [number has been updated - thanks, Jon]. For a sense of how cost scales with size, note that the Falcon V lifts almost ten times the payload of the Falcon I, but costs a little more than three times as much. Each SRB has a bit more than 7 times the thrust of the Falcon V first stage.

    NASA faces a difficult choice for the upper stage. There is only one man-rated engine suitable for upper-stage use in production in the U.S., and that is the Shuttle's SSME. That engine is complete overkill for an upper stage engine, because it's designed to work in the lower atmosphere too, which makes everything more complicated. Throwing it away each flight will cost a lot. Any other engine (i.e. the in-development Cobra or the in-production RS-68) will require at least some development money and time to certify as man-rated, but will cost less per launch.

    All the engines NASA is considering for the second stage burn both liquid hydrogen and liquid oxygen. This decision alone pushes the cost of the NASA solution far away from nearly anything else. LH2 will give better performance than kerosene (4300 m/s exhaust velocity versus 3330 m/s, measured in a vacuum), and thus a smaller rocket, but the relevant difference is cost. NASA can't go with a lower cost propellant combination because there are no US-manufactured man-rated engines which burn anything less costly.

    Now that we know why NASA is mulling an expensive crew vehicle, and what a less expensive vehicle looks like, and interesting question is, how could we end up with the cheaper alternative? I assume, in particular, that the SpaceX honchos think about this problem relatively often. I also think that Michael Griffin, the NASA chief administrator, thinks about this fairly often as well.

    It's a political problem. NASA has to get crews to the international space station after the Shuttle is retired. The Russians have complained about being solely responsible for launching crews for the last few years, but that is because we weren't paying enough for the launches. If we were willing to pay, the Russians would be happy to provide launch services (they recently asked for $63M per launch). They have a very dependable launcher, which costs a fraction of a Shuttle launch. Buying time to design and build a better, cheaper U.S. launcher would be cheaper than building the stopgap crew launcher currently envisaged.

    We would then be faced with the smaller problem of launching the ISS portions originally intended to go up on the Shuttle. Both EELV boosters have the mass capability to launch these cargoes (though NASA would have to rework each piece to sit in the EELV payload fairing rather than in the Shuttle payload bay). EELV launches are expensive (around $254M), but they're half of a Shuttle launch, and don't endanger crews.

    Michael Griffin is going to take the expensive but politically necessary route. He'll pay the big NASA prime contractors many billions of dollars to develop a stopgap launcher, while ensuring that SpaceX and perhaps t/Space and Kistler get sufficient funding to get launch histories. Eventually, perhaps after his tenure, it will become clear that the startup U.S. launch companies are safe enough and obviously cheaper enough to mothball those horribly expensive launchers. This comparison will have to be painfully real, immediately obvious, and undeniable. Only then can the NASA prime contractors be fired and the money formerly used for their support used instead for space exploration.