Believe me, I'm as thrilled as anyone that we now have an interplanetary giant robot vaporizing an alien landscape with lasers! That fact is though, unless you have a plan for large, near autonomous swarms of exploratory robots, a decent sized human exploration mission has the potential to get more bang for the buck. A human, even stuck in a space suit, is just so much better at going out to a site, then excavating, bagging and tagging, then analyzing a bunch of samples than any existing robot. It doesn't even seem to matter that we're technically reliant on machines of one kind or another for pretty much every stage of the process, we're still better at it for the moment.
I'll disagree until you show me some evidence. Presumably you think the same way.
The evidence is that the Concorde put in nearly three decades of service. Things that are impractical to the point of impossibility aren't kept in service that long. That's actually a decently ripe old age for an international passenger jet. During that lifetime, people wanted to fly on it, paid their money and flew on it. It successfully filled the niche it lived in.
You agree with me, but seem to be fighting anyway.
We obviously have a different definition of what a beancounter is. I go by the fairly standard definition of a penny pinching accountant who is incapable of grasping the big picture. For example someone who eleminates a bunch of neccessary $20/hr jobs and compensates by dumping the duties of those jobs onto $80 an hour employees. Or someone who eliminates a less-profitable division because their definition of profit doesn't discern between less-profitable and unprofitable.
Go back and read my original post on cost:
I obviously read it since I quoted it in my last post. You provided the Concorde of something that was "sooo expensive that the problem isn't worth solving" and were basically implying that a working supersonic passenger is basically an impossibility. The history of the Concord seems to prove otherwise.
Also, I realize now that I should have pointed out that, for the Concorde itself, what really killed it was old age. The other things I mentioned were contributing factors. They were more central to the death of the supersonic passenger plane in general than the Concorde specifically.
See, we agree!!
OTOH, technology marches on.
Now that Pratt & Whitney has developed a supercruise engine for the F-22, if Boeing demonstrates that the 787's carbon fiber body is durable, then combining those technologies with NASA's boom reduction research the concept of supersonic passenger aircraft could be brought out of mothballs (especially for long Asian and Pacific routes).
Interesting. I have my doubts about the carbon fiber body being able to withstand the heating/cooling cycles of supersonic flight, but it certainly is possible that supersonic passenger flight could re-emerge.
Anyway, you never did answer my question of what handwavium is required to make electrolysis work as an oxygen generation mechanism. It can't be the technique itself, it's known to work and there are commercially available units. The water can't be the obstacle, since we now know of numerous spots on Mars where you can just dig under the dirt a little and hit a layer of pure water ice. So what part requires the handwavium?
>. Ma Bell was an evil monopolist until their forced breakup in 1984, which it turned out, didn't help much.
Really? How are you paying $2 to $6 when everyone else in America now pays a fraction of a cent? The breakup did in fact help. You do not need to lease/rent your telephones from Ma Bell, you can add as many phones as you want and you can pick your choice of voice carriers - including free VOIP providers if their offerings fit your needs. The "videophone" is now reality and most of us bave far more data bandwidth coming jnto our homes than the "fattest" arpanet links offered. There is no way whatsoever that the breakout did not help consumers.
It's the getting the Martian water which I think is much more difficult than you do.
There are plenty of deposits of water ice all over Mars. If you want pure water ice you might need to truck it from the poles but, otherwise, you can get water from the ground from locations all over the planet.
Well, in order to get enough water to make oxygen for one astronaut for one year, you need 366 kilograms of water. For them to drink and possibly rehydrate freeze-dried food for an entire year with no water recycling, you need about 1464 kilograms of water. So, for a whole year (ignoring things like washing water, etc. which you can continuously recycle even if you aren't recycling drinking water), a single astronaut needs maybe 1830 kgs of water to live. which is about how much water you can get out of an average 13 cubic meters of Martian soil. Unless you're in a poorly chosen area, that's not going to be very hard to obtain. That's not going to be a year's worth of work to obtain. Anywhere from a day to maybe a month at worst depending on what equipment you're using and how well chosen your source is.
That's not my recollection.
Then your recollection is incorrect. The Concorde had trouble recouping development and safety testing costs, to be sure. If you try amortizing those costs over only twenty units, you're obviously going to struggle. The operating costs themselves, are all we need to consider here, and they were modest for what the Concorde actually was. A more modern big passenger jet gets about three times the fuel economy per passenger, tops and other costs are comparable. That's not really "sooo expensive". It's first class prices, sure, but it's not astonomical. If we'd continued with supersonic passenger jet design, the fuel consumption per passenger would have gone down just like it did for the jumbo jets. It certainly would have always required more fuel per passenger, but not that much more. The Concorde was basically killed by beancounting and politics. It wasn't some impossible thing.
Silly fly-over hayseeds not wanting their windows rattling multiple times per day!
The concerns about sonic booms were greatly magnified by military tests producing much more powerful sonic booms. It led to lots of politically motivated rules about where the Concorde could fly or even land, completely ignoring the fact that the Concorde could also fly at subsonic speed and, in fact, had to for takeoff and landing.
It's the way that you wrote:
That's a good thing... for example...
It suggests that your examples were of good, proper attitudes.
Anyway, that misunderstanding aside, I have to agree with you that we shouldn't be pulled in the direction of every new idea "just because". But the crank Electric Universe theory is not the same thing as the drive for exploration. Among other details, the drive for exploration is not new. It's ancient. If we didn't have it, chances are pretty good we would have gone extinct ages ago. It drives us to develop new technologies and new science and just generally try new things. I've seen you argue that we don't have the technology to do various things a Mars colony would require, with the implication that we shouldn't try for a Mars colony because we don't have those things. But why would we even develop those things if we weren't going to colonize another world? Necessity being the mother of invention and all that.
You wondered why I thought of your attitude as nihilistic. It's because your answer to the general question of "if not now, when" seems to be "never!". To me, that just seems like a total surrender.
It's really hard to read what you wrote there without coming to the conclusion that you're arguing that racism is a good thing. Or, at least that racism is a good default position and you should only switch with extraordinary proof that it's bad. I don't think I like that.
I don't understand that response.
I was saying that "Because it's there" is not a Very Nonsensical Reason. At least, if it's not a good reason, then most of the motivations for all the great things the human race has accomplished are also not good reasons.
I'm curious, which part of electrolysis requires handwavium? That's how the oxygen is generated on the ISS. All that's required is water, and Mars has water. The fact that it takes some effort to extract it doesn't make doing it somehow impossible. To my mind, that's the crux of the disagreement between us, you believe that things that are difficult shouldn't and possibly can't be done.
(This is similar to -- but on a much larger scale than -- why we don't have supersonic passenger aircraft: some problems' only solutions are sooo expensive that the problem isn't worth solving.)
Except that the Concorde wasn't that expensive compared to a regular passenger jet. It was killed by noise concerns and irrational safety concerns and the fallout from the events of September 11th 2001.
You'd better reopen Hanford PDQ.
If you want plutonium-238, certainly you would need nuclear power plants to make it. I don't insist on RTGs, they're just one option with certain advantages when you're shipping equipment to far off location and need to power it reliably for a long time.
I've wondered that many times, and have never come up with a good reason for why people live (as opposed to "endure in mining camps") in deserts.
That's the point I was making about your argument. Just because you personally don't get it, or it's outside your comfort zone, doesn't make it pointless.
To make life less precarious, less of a drudge. Let me rephrase that: to make life easier.
In retrospect, those things obviously made life easier and better. Beforehand, you can be assured that there were plenty of naysayers like yourself who demanded to know why you would want to have anything to do with fire, or horses, or putting things on wheels when you can build a perfectly good travois.
To leap from "it's stupid to live on Mars" to "it's stupid to live at all" is... too absurd for words.
I think I said that because you said:
"Because it's there" is a Very Nonsensical Reason
And it simply isn't. If that's not a good reason, what is?
Antarctica gets far less precipitation than Arizona.
In the interior, yes. Coastal areas tend to get a decent amount, however. Either way, both Arizona and Antarctica get a lot more precipitation than anywhere we would initially colonize on Mars.
Under a *deep* -- and therefore very expensive -- gravity well.
It's all going to be expensive. The point is that you don't have to build an industrial chain on Mars from scratch. You take along the supplies you need to start and bootstrap it from there. You use in situ resources, but you don't use them to make everything from scratch, you use them as a multiplier for what you do bring along with you. For example, an entire lifetime (obviously not a lifetime of luxury) of supplies for an astronaut would be about 150 tons. That's food/water/oxygen/clothing/sanitary supplies/medicine. At current launch costs, that's about $4 billion per astronaut for the launch costs to get it off Earth.
75% or so of that mass, however, is just water. Even if you ignore in situ resources entirely, you can recycle water used for human consumption. There are consumables involved in the filtration that require a significant industrial chain to actually make, but you can recycle thousands of kilograms of water for every kilogram of consumables you bring. If you're using local water, you also need consumables. But you can bring those along with you and use a small amount to use a large amount of in situ water.
Oxygen is a bit trickier since we don't have a good process for cracking CO2 yet, but this is where we stop ignoring the in situ resources and acknowledge that, with some basic equipment, you can get oxygen from water (or from perchlorates, or from other materials) on Mars. There are consumables that you can't reproduce on Mars without an industrial base for that as well such as filters and electrolyte/catalyst membranes but, once again, you can bring along a relatively small mass of consumables and use them to generate a lifetime supply of oxygen from local resources.
Mine it and process it?
That is the way such things work, yes. Although, rather than mining and processing, you'll be extracting material from the air and processing in some cases. Did you think that anyone was suggesting heading down to the local Martian department store?
So, 200 wheelbarrows full of rock on Earth would be like 600 wheelbarrows of rock on Mars? Get back to me when you've moved 10 wheelbarrowfulls(sp?) of rock 100 yards.
Mass would be the same, weight would be less. So, without frequent stops and starts, it would be easier. I'm not sure why you think it would be otherwise (except of course for the obvious fact that you'd have to do it in a spacesuit).
Also I'm not sure about taiwanjohn, but I've moved a lot more than 10 loads of rock, soil, compost, whatever over my lifetime. On decent ground, without much of a slope, it's pretty easy. Even when I was 10 years old or so. That's the whole point behind a wheelbarrow. Loading the wheelbarrow has always been the hard part.
Obviously "a couple of shovels" is a bit of an understatement.
And the buttload of infrastructure to convert the local material into something usable by the 3D printer?
Not sure about metal sintering 3D printers. I gather you need powdered metal, iron or some alloy thereof along with a wax binder. Presumably you can recycle the wax to a certain degree. For the metal, you have various materials readily available on Mars. Iron is clearly widely available on Mars either as iron oxide in the soil or as fairly pure iron from meteorites. Overall though, I would think that it would be best to save the 3d printer for complex metal parts. For something like a shovel it would be better to use relatively traditional blacksmithing methods.
Go see how he made it. I guarantee you that there's a huge load of complex Earth infrastructure behind it which would have to be replicated on Mars.
The experiments in that article were about getting it to set under Martian conditions. A commercial Sorel cement product was used. It didn't look into what kind of infrastructure would be needed to actually produce it. It's worth noting that, although cement is typically made in giant industrial kilns and ground in giant grinders, there's no reason you can't also make it in much smaller batches with modest equipment.
I wouldn't get my hopes up...
I was including more modern designs like SRGs under the blanket term RTGs. The more modern designs get at least 20% efficiency. So, with 1 kilogram of plutonium 238 producing 500 Watts of heat, you would get 100 Watts and still at least 75 Watts after 30 years. The terrestrial section you linked to is mostly for obsolete equipment. The space section is more representative of what you could expect of anything sent to Mars. It includes a design that masses 35 kilograms total, and produces 140 Watts from 500 Watts of heat from 1 kg of fuel.
A piece of construction equipment like a Komatsu 300 uses about 5 gallons of gas per hour. 5 gallons of gasoline is about 661.2 MJ, so 5 gallons per hour is a rate of about 183.667 kilowatts. Exactly how to equate that to the power efficiency of radiothermal generation depends on a few factors. The most "efficient" (in terms of energy conversion) way to operate heavy equipment from a radiothermal source, ignoring all other considerations, is to run it off a stirling engine directly powered by the heat of the radioactive fuel. In that case, you can pretty much directly equate the 500 thermal Watts from 1 kg of pu-238 to thermal Watts from gasoline and say that a radiothermal-powered Komatsu 300 would need about 368 kgs of pu-238, or about 490 kgs to have that power level 30 years out. The actual engine would obviously need to mass more than 35 kg, but would also obviously not need to be in excess of 17 metric tons as I'm pretty certain the Stirling engine design would scale a bit more gracefully than that. Of course, you won't be running that piece of equipment 24/7. Most likely, it would sit idle nearly all the time, except for short periods of intense use. Not to mention that, for a Mars mission, you will want equipment with a modular, interchangeable design to reduce weight. So, you'll probably have a power plant somewhere and distrubute power either as electrical power over cables or by using the power to generate fuel that you can store for later use (methane and oxygen again).
Maybe the Atacama desert would be better?
If the construction crews wore the kind of suits that someone would wear at 115,000 ft altitude.
That very well might be a better test. On the other hand, it wouldn't simulate the different gravity on Mars at all. Also, performing all of the constuction under such conditions wouldn't be practical. Experimentally, it should be sufficient to have part of the construction crew working under those conditions for long enough to adapt to them and then guage their effectiveness in various tasks and extrapolate from there.
Where will all of the feed stock come from?
I've got the sneaking suspicion that lots and lots of people don't realize what a really, really deep chain of industry is required to build something as simple as a one-speed bicycle.
From the atmosphere and the ground, respectively. Zubrin's plan for generating methane fuel on Mars didn't even call for using electrolysis on in situ water, but rather for bringing a relatively small amount of initial hydrogen. There's no reason, however, that we can't use in situ water as a resource as well. As for other materials you might need for various processes, you would bring them with you initially.
Same thing for the tools required. There's no reason you need to build everything locally to begin with. A bicycle, for example. It may take a very deep chain of industry to build a bicycle but, if you bring 5 bicycles and a supply of replacement parts and repair tools, there's no reason you can't still have three servicable bicycles thirty years later.
My fault. Should have said "tunnels", because maybe there aren't Martian caves where we think it's best (or even "ok") to live.
There are Martian caves/lava tubes. As long as you find one the right size, there's no reason you can't make use of it to live in. There are also plenty of depressions and canyons that you can use to make the task of creating an underground shelter easier.
And even if there are, what if they have to be extended, enlarged, strengthened, etc?
Then you extend, enlarge, strengthen and etc. them as needed. The primary reason you want something underground is radiation protection. You don't actually even need a cave for that. Even if you just build a lean-to next to a cliff, you've just cut radiation exposure in half. Find yourself a site at the bottom of a canyon? That can drop radiation exposure by around 90% or more without needing to do any excavation or construction.
Bottom line: why would anyone live in a place that's drier and colder than the Atacama, has much less atmosphere, and is a minimum of 34M miles from everyone else? (Because of the distance and gravity, "Because it's there" is a Very Nonsensical Reason.)
For that matter, why would anyone want to live in the Atacama desert? Or any desert? Why would anyone ever need to build a boat or domesticate a horse, or cross a river, or build roads, or invent trains, or start mining for ores? For that matter, why bother to feed yourself, or get up in the morning or do any of it? Your question seems nihilistic to me.
You're providing incomplete, one-sided calculations. So this is propaganda.
Speaking of incomplete, I notice your post has no calculations whatsoever. Don't just sit there and say, "You're wrong!" Tell me why I'm wrong and provide whatever it is you think I'm missing.
_It is true pipelines would transport oil using less carbon emissions compared to rail transport. But they also reduce transportation costs, thus allow more oil to be used and allow oil to undercut renewable sources of energy. So it makes sense to oppose the pipelines._
No. No it doesn't. You are intentionally trying to make oil more painful so people won't use it. This only makes sense when there are viable alternatives. Sorry, but wind and solar won't get the oranges from the groves in Florida to markets in Maine. All you are doing is making everything more expensive needlessly, benefiting the Chinese worker, punishing the American worker, and again, you are increasing the amount of CO2 that gets put into the atmosphere.
Somehow, this doesn't seem very smart.
_ Any single rail accident would spill far less oil than a spill or break in the oil pipeline._
Are you sure about that? Remember, that we are not just talking about rail, but also tankers that will take the oil across the ocean to China. Then, of course, the Chinese will refine it, using God knows what kind of environmental safeguards. Once it is refined, it will be loaded back into a tanker or pumped through Chinese pipelines. Still think this is a better idea than a single pipeline to US regulated refineries?
_And these accidents would create enough pressure to make the rail transport of oil safer._
But pipeline accidents won't create pressure to make pipelines safer?
In all fairness, I haven't heard anything good coming from a pipeline. All the news about them have to do with spills and cover-ups. I'd be happy with a small headline announcing 5 years on a pipeline without a spill. Then we can talk about adding more pipelines. Until then, I'd rather the spills / fires be contained to the limited size of a shipping container.
There is about 100,000 miles of oil carrying pipeline in the US. If they ran a story every time one went 5 years without incident, there would no time to write about anything else.