Now, be aware that the average family spends 104% of their income. If you go from $600 a week after taxes to say $245 a week (or whatever the maximum unemployment benefit is), you have to start "load shedding", and cut unnecessary spending.
No. The time to start load shedding is the moment your expenditure exceeds your income. Period. (Most of your scenarios can be rendered moot by this simple tactic - living within your means and saving the excess above expenses against a rainy day. The remainder are edge cases.)
Sooner or later something is not going to be paid, and once it's reported, there goes your credit rating! And now, again, you're unemployed and can't get work because of your bad credit rating!
That only happens if you have been stupid! If you live within your means, the chances of these problems drops dramatically.
This is part of an excessive reliance on perfection - especially perfection that is irrelevant to the subject - that has so destroyed the culuture in Japan, for example
Asking people to live within their means and excercise common sense is hardly 'reliance on perfection'. In fact, until very recently in the West it was considered common and desireable to live within ones means - and society very decidely didn't get ruined by centuries of this.
How is this any different than saying that lower income families typically are unwilling to live within their means?
Try "unable to live within their means". Housing, fuel, and health costs have skyrocketed while wages have stagnated or even declined.
So? Putting bills on credit cards makes things worse.
If you can't afford to have a baby, perhaps you shouldn't be risking it, and so forth.
Don't be an elitist ass. Shit can happen to you no matter how well prepared you are.
Sorry, no. Babies don't 'just happen'. Just like bad credit *you* have to take deliberate action for it to happen. (And modern birth control very, very, very rarely fails. Use birth control and don't have sex during the females fertile period and the odds of something 'just happening' drop to essentially zero.)
Tv's and air conditioning aren't 'necessities'.
Read up on this summer's heatwave and you'll find dozens of people died because they had no air conditioning.
Right. That's why people lived for centuries in hot climates without air conditioning. The problem isn't lack of air conditioning - but lack of conditioning themselves for hot weather.
Nor is steak(or any meat for that matter)
Hardly. A pure carb diet is very unhealthy, and a great ticket to obesity and diabetes.
Hardly. Protein != meat. It's quite possible to have a meatless diet and to quite healthy.
If you can't get a job, you can't make the payments. This effectively relegates the poor to a permanent poor status.
No, it relegates the stupid to permanently poor status - because if you are poor, you are brain dead to run up any significant credit card debt. Heck, even if you aren't poor, it's stupid to have any credit card debt.
I think that it is in the best interest of a business to make themselves accessible to the widest audience possible,
Certainly that is true - but there does come a point of diminishing returns. If the database that drives Target's website doesn't have a field for the alt-text - then the database has to be redesigned and the data converted over. Then someone (actually a lot of someones) has to create and enter the text for thousands of products - plus the continuing cost of creating and adding it with each new entry. Not cheap! If there aren't enough blind customers to justify this cost - then their vested interest lies in not spending money that can't recoup in a reasonable time.
Nasa has said in the past that it would be unsafe to retreve the hubble and bring it back to earth because of its weight causing problems during landing.
While that's a popular legend - its false. NASA has never said any such thing.
The truss that is currently in the shuttle weighs much more than the hubble.
There are actually two weight limits - the 'safe limit' and the 'safe once' limit. If you have to land with a payload greater than the former, thus being in the 'safe once' zone, then the vehicle has to undergo a series of special inspections to ensure the structure and landing gear was not damaged. (Hubble is in the 'safe always' zone.)
A little shadow anomaly isn't going to seriously dent the Big Bang theory. There is so much evidence for the Big Bang and predictions based on it have been observed that it will take more than a little inconsistency to make the theory suspect. You need something more substantial than shadows to expect a rehauling of the Big Bang.
No, I wouldn't expect and overhaul of, or gross changes to, the Big Bang theory - but when a prediction made by the theory fails to pan out, it needs to be explained. Maybe the theory is faulty in the fine details, or an assumption or two is wrong, or the implications of other portions of the theory are misunderstood. This means that, at a minimum, a careful re-examination may be in order. (The first step of course is to rule out a problem with the WMAP probe - in design, construction, or operation. The details of the analysis performed by the physicists of course will also have to be closely examined.)
Or, to put it simply; it's far too early to make any comments about changes to the theory - there are more than a few steps and considerable work to be done, to verify or disprove the results in the [scientific, not news] papers.
You can "colonize" Mars all you want. Without precious foodstuffs and volatiles from Earth, what are you going to eat when Sol 3 goes under?
Seeing as how Mars' atmosphere has a lot of CO2 in it, and photosynthetic organisms do pretty well in such an environment, I'll probably eat a lot of green leafy things.
Sure. Once you get a nuclear reactor there to provide heat and light - but when the reactor fuel runs out - what then?
If you are no longer contributing, then your voice still won't be heard. Reputation on Wikipedia is immensley important. That makes sense: why would policy decisions be made by those who haven't proven they understand the goals of the project or those who don't have a track record of improving the site by contributing articles?
You miss the OP's point - reputation isn't made by proving an understanding of the goals, or by contributing articles - it's made by amassing a large number of edits. They key problem with this is that and edit can be anything - even a quick spelling correction earns you a line in your earns you a line in your 'user contributions' log, and creating a new article equally gains you single line...
My opinion is that anyone treating all edits are equal and using that to derive a metric for measuring user contributions to the site is using a seriously flawed method. Selling the output of this method as "The Truth about who Created Wikipeida (or the Tale of the Noble 500") is just trying to invent history to fit their preconceived notions.
Which is precisely the primary modus operandi of Jimbo Wales - he cares little for facts or truth, he cares much about his vision. When facts and truth don't fit the vision, they are discarded and ignored in favor of spin.
[Snippage discussion of economic conditions post-911.]
Perhaps the Segway would have met the same "meh" fate either way but does anyone think that, had 9/11 never happened, the Segway would have met a better response?
No, the problems with the Segway itself still would have been place - and price was only one of them. Its still not really compatible with the real word, and its still a 'solution in search of a problem', no matter what the economic conditions are. Possibly, pre dot-bomb, they'd have sold more units - but it still is extremely unlikely to have been widely adopted.
The actual text of the bill, found here - http://www.legislature.state.oh.us/bills.cfm?ID=12 6_SB_17 shows it to be a lot less scary than the alarmist article says. What it actually reads is that those accused of sex crime but have passed the statute of limitations will have to register if a court finds a preponderance of evidence that that person is guilty.
Taking the statute of limitations and tossing it into the trash isn't scary? Reducing the burden of proof the State must provide from the criminal standard to the civil standard isn't scary? Removing the right to trial by the jury of ones peers isn't scary?
Just how thoroughly do the protections built into our legal system have to be trashed to scare you?
It's true that Zubrin's book is idealistic (I was rolling my eyes a few times). Nevertheless it is a very elegant idea. By producing the fuel for the return journey on Mars itself we eliminate in one stroke all the Battlestar Galatica-size fleets of ships necessary to transport the fuel, and construction and staging areas in orbit and on the Moon etc.
That assumes that the process is in fact practical - elegance != practical. Even if it is practical, you don't eliminate as much as of Galactica effect as you might think - the reactor and processing facility is still going to be large and heavy (and difficult to land), not to mention the large (and not so heavy) tanks to store the produced fuel. Not to mention the difficulty of getting all the units hooked up once on the Martian surface. The proposal also introduces an additional complication in that you must land your return vehicle, rather than leaving it in orbit - which places some significant design contraints and potentially adds failure modes. (Not to mention the fact that they return vehicle, even though its 'fluffy' at that stage, is a large and difficult-to-land component in its own right.)
As I said, no obvious showstoppers - but once you actually start digging into the details its unclear that in situ fuel production is better than more conventional schemes. It removes some hurdles - but it also introduces some new ones.
It is insane that people are talking about the Moon as a stepping stone to Mars.
It is, and it isn't. On one hand, very little about Lunar suface operations can be directly and usefully transferred to Martian surface operations. The environments of the two are simply too radically different. OTOH, a Lunar base is not much different (conceptually) from Apollo's 8-9-10 in the it provides valuable operational experience for the Mars mission itself. (Not just orbital experience, but ground processing, planning, etc... etc...)
Instead of blowing wads of cash on the ISS for no apparent reason
If you are serious about going to Mars, the ISS or something like it is a vital component of the program. A Martian mission will spend most of its time in the cruise phase - in weightlessness. Thus we need to study the long term effects of weightlessness and determine whether or not a heavy (and complicated and expensive) centrifuge system will be required. We need to study and qualify the life support system, which will have to work for years on end. Ditto for items such as the computers, science equipment, logistics provisioning, etc... etc.. I agree, ISS isn't doing this very well at the moment, nor is it planned to, but it can be made to fill that role.
we could be doing engineering on the problems you outline.
Actually, we need to do detailed basic research followed by detailed design and trade-off studies on both concepts - then and only then can we make a rational choice between the two. It's not clear that in situ fuel production will be better than envelope expansion on more conventional, and existing, methodologies.
Seems much more practical IMHO.
Unfortunately, what 'seems' practical may or may not be once you get down to the nitty-gritty details. Assuming that because it 'seems' more practical, especially with the utter and complete lack of evidence that it is more practical, that it must be 'the way to go - is a fast way to potentially end up in a very deep hole with a lot of money spent and nothing to show for it but a negative result.
I know there is a lot and handwaving and 'but on the gripping hand' in this reply - but that's the nature of the subject matter. We simply don't have enough information on either option to make a clear black-and-white call. We may never be able to render it thus, and be placed in the position of rolling the dice with little more than knowing the odds to some unknown degree of precision.
I'm glad to see that most Slashdotters are financially independent - or in a situation (like living in a relatives basement) where having money is irrelevant. I can see no other reason why most of the advice to date boils down to 'quit your job and run'. Few people outside of Slashdot are in such a happy position I suspect.
Zubrin's very well-written book makes a compelling argument that a bit of cleverness and rational analysis would go a lot farther than the "drive your truck to Mars" approach (perfect "feel good" weekend read).
The problem is - Zubrin's cleverness and and ability at analysis is matched by his overconfidence in the products thereof. He has a strong tendency to treat his ideas as if they were simple solutions with no real development needed, ready for deployment fairly easily - when the truth is that they are anything but. His Nuclear Salt Water Rocket for example has never been modeled, and only examined on the theoretical level at the grossest of scales. Yet he, and his disciples, treat it as if it were mature technology ready for use with only a few tweaks. The same is true of his scheme for producing fuel in situ on Mars. No developmental work has been done, and very little basic research - yet he argues it convincingly enough that many people assume (as does the poster you are replying to) that its a 'done deal'.
The Case for Mars *is* a feel good read - but that's about all it is. It's much close to fiction than reality. The 'truck driver' schemes keep coming up - because they are (in the main) something that can be accomplished by working within the bounds of existing or near term technologies (the GP vastly overstates the case), while Zubrin's are almost completely undeveloped and are at or beyond the bleeding edge.
This is a myth. We only need to send 6 tons of liquid hydrogen and a small reactor. In a 2-step process you can use this to create 108 tons of fuel. You fly to Mars with just enough fuel to get you there, create your own fuel from the Martian atmosphere, and fly back. To make things less risky, we send the first one unmanned, so there's a return vehicle on the surface of Mars all fueled up when humans arrive.
And now, as Paul Harvey says, for the rest of the story. The part Zubrin and his cabal won't tell you...
This process has never been tested beyond the laboratory workbench. There are a large number of very significant hurdles to getting such a system operational on the Martian surface. Among them - insulation; Mars has enough atmosphere that MLI won't work, and this means large, bulky and difficult to handle tanks for receiving the output product. Another is filtering the input feed (to get rid of the atmospheric dust), as well as keeping the filters themselves clean. Etc... Etc... No obvious showstoppers I admit, but some very definite steep hurdles.
This is clearly described in The Case for Mars by Robert Zubrin. Surprised more people haven't read that.
Many people have read The Case For Mars - many of those have gradually come to understand how much of that book is smokescreens, handwaving, and wishful thinking. Robert Zubrin has a very bad habit of assuming that coming up with clever schemes means that implementation is a simple straightforward thing - even when they represent quantum leaps over existing technologies.
If I am going to the moon, I would like to have a company who has a history of building manned spacecraft.
You are pretty much stuck on this rock then - because there isn't such a company in existence today. *Nobody* has any current experience in designing manned spacecraft. Even the Russians limit themselves to modest modification to their existing craft - it will be very interesting to see how Kliper plays out (assuming it ever gets built).
Both solar flares and cosmic radiation are serious (and potentially deadly) barriers to space exploration. Near the earth things aren't too bad, but a journey to Mars presents a serious problem.
Last I heard, there were no practical ways to deal with radiation in space.
You must have last heard back in the 50's or so.
Does this mean NASA doesn't consider radiation to be a problem, or think it has a workable solution? Is so, what is it?
The solution has been known for decades - provide a 'storm cellar' to take refuge in during these (fairly rare) 'storms' (flares), using your potable and waste water tanks for shielding. It's fairly straightforward within the limits of our current knowledge. Day-to-day radiation exposure will be somewhat higher than current safety limits, but barely enough to be 'serious' let alone 'deadly'. (Me, I'd take the 10-15% greater chance of inducing cancer if I were still in a position to have a chance at a berth on a Mars bound ship.)
And isn't it irresponsible to begin contracting if they don't have a solution?
Because this contract covers mostly the LEO and Lunar phases of the missions, it's pretty pointless to handwave and play Chicken Little about the Martian phases.
This is a MOON lander, which could one day may be used to land on Mars, but probably would require changes due to differences in gravity, atmosphere, etc.
Before taking the submitters/editors to task - you yourself should get your facts straight. This contract is for the Orion CEV - analogous to the Apollo CSM. It won't land on either the Moon or Mars - it's an orbiter.
No, it really doesn't. Half life determines the rate of voltage decay - but it doesn't determine the lowest voltage at which the system(s) will operate. You can have a RTG with a half life of two centuries - and still have a dead probe after twenty years. You can have an RTG with a half life of fifty years - and have a probe operating for forty. Half-life is only a very misleading portion of the story.
Twenty years after launch, the Voyager RTGs were still putting out about 70% of their initial inital launch power (335W vs 470W). Twenty years after the ALSEP placements, they had been switched off for 12 to 15 years.
And? RTG's decay at a fixed rate - regardless of how much power is drawn. If you have acess to the original specs you can calculate how long the ALSEP is likely to have remained active (based on power levels).
Yes, the Lunar environment is harsh -- although the temperature swings are much less frequent (but same range) than for any spacecraft in orbit close enough to pass through the nightside shadow.
Again, correct but misleading and incomplete. Unless you are *really* low, the nightside shadow only lasts half an hour or so - not enough time for a properly designed spacecraft to cool down significantly. OTOH - Lunar night is more than low enough for everything unheated in the ALSEP package to drop down to cryogenic temperatures. These cooling and heating cycles place a great deal of stress on connectors (not all of which on the ALSEP were heated) and on the insulation materials used.
And (except for A14) the ALSEPs had been operating just fine for up to 8 years when switched off.
So? I've seen equipment that operated just fine for over a decade up and die - all lasting eight years means is that the equipment lasted eight years. That figure has no predictive power whatsoever.
The ALSEP packages were turned off remotely when the budget for collecting data ran out. That was Sep 30, 1977. Although the Apollo 14 ALSEP had failed a year and a half earlier, the others (A12, A15-17) were still going strong -- and still would be, the RTG power source having about a 90-year half life. (Well, barring hardware failure.)
It's not the half life that matters - it's when the output voltage drops below a useable value. The half life of the RTG's on the Voyager probes is comparable - but they had to start turning off instruments years ago, and the RTG is expected to stop producing sufficient power to operate anything in the next five years or so. Furthermore, the environment on the Lunar surface is extremely harsh, much harsher than that the Voyagers are exposed to. (Mostly due to the large temperature swings on the Moon. The Voyagers are colder, but the temperature is steady.)
[snippage verbal diarrhea designed mostly to give 'ltbarcly' a sense of superiority]
You responded to my post by saying my claims were wrong, but now you are saying that my examples aren't good enough.
Your original claim was that the themes echoed throughout Heinlein's work - I never claimed anything about your examples beyond pointing out that they failed to support your initial claim.
You said that my examples of Heinlein themes wasn't accurate.
No, I said they did not echo, as you implied, through all his works. Your own examples bear out that I am correct.
You're trying to turn a little joke into some sort of heinlein dual, because my joke was a response to your post where you mock an author.
I didn't mock Robinson - but made a critical statement of his authorial capabilities. (And one not original with me either, it's a fairly widely held one. There's a reason why Robinson has dropped off the best seller lists you know.) Drop by your local bookstore and read the back cover of his "Very Bad Deaths " and you'll see a prime example.
Now, as for "The Roads Must Roll", you say that the bad guy (Van Kleek) gives up because his army had been defeated and the station blah blah blah. You are completely wrong here, as Van Kleek doesn't give up, but rather is tackled and knocked out by Gaines, who goads him away from the self destruct switch he had set up by mocking him and poking at his insecurities
In other words - we are both wrong. Because he was defeated by being tackled, even if it was the heckling that opened the opportunity.
Please refrain from taking the microscope to my lighthearted banter in the future.
You don't want your words examined closely - then don't utter them in public.
Eat it pretender! Never question my heinlein bona fides!
I have no need of questioning them - you prove your lack of them each time you write. Your original claim was that the themes you quote repeated through 20 books (though his actual total is over 50). Yet above, you identify only seven books, and one short story. One (talking like 30's gangsters) is demonstrably not present in 'Every Heinlein book that there is'. Another, 'convince a bad guy to give up because of logical fallacy' is patently absent from the short story. (He gave up because his 'army' had been defeated and the station he had gained control of had been cut out of the control circuits.)
If there is a pretender in this conversation - it is not I.
there were very few sex scenes in his novels prior to about 1968-ish.
Probably because his editor and/or publisher objected to them. Overtly sexual passages in fiction were frowned upon in the increasingly puritanical morality of the 1950s. Even subtle hints of sexuality were banished. This was done in the name of saving our innocent virgin minds from such filthiness.
But, then the swinging 1960s rolled around and it wasn't such a concern, anymore. That attitude prevailed until the 1980s, when Heinlein really began to cut loose. As an example, "Friday" is probably the best-known Heinlein novel from the 1980s, and it's not because it was an outstanding literary work.
"Friday" is his best known work from the 80's because its essentially the only readable work of his from that period. The 'sex scenes' are a very minor proportion of the total book - anyone who focuses on them is an individual with very deep problems. (Or who lacks the wit to examine and discuss the larger issues inherent in the book. Or wishes to avoid doing so because of the depth and difficulty of doing so. I suspect the latter is the real reason, as Heinlein didn't write simple easy-to-categorize books.)
I think for the people who long for the books of the successful Heinlein, say 60's and 70', Robinson will be a good choice. He is very familiar with the works and continues to write in the relaxed, almost trivial, style of this time. This is not a bad thing,
It is a bad thing - because the story outline was prepared in the 50's and thus is most likely intended to have been written in style of his [Heinlein's] 'juveniles' or his short stories of that time. By the 60's his style had changed considerably.
I agree. Spider wrote one of my all-time-favorite short stories, "God is an Iron", and Stardance is still one of my top ten SF books, mostly because he has a knack for bringing his characters to life and making them real people. But like Heinlein in Number of the Beast, Job, and others, SR is definitely following in RAH's footsteps with each successive Callahan book being more and more implausible and "out there".
The key difference being that it took RAH thirty years - while it took Spider a little over a decade, to 'lose it'. RAH's 'out there' books are a scant handful out of nearly sixty, while for Robinson its well over half of thirty. (I agree "God is an Iron" ranks in the all time greats.)
For a while I followed his work religously, and I rejoiced whenever I knew a new book was coming... up until I found out that each new book was yet another set of stories from "Callahan's Bar". I thought we'd gotten rid of 'em when he burned the place down, but no such luck.
I remember 5-10 years back on alt.callahans, Spider complaining (via a proxy) about the poor sales of a collected version of the first three Callahan's books. My response was "what the hell did you expect Spider? It's not like they've been out of print or haven't been available".
Enough is enough: SR needs to stretch his legs and explore some new worlds.
That's my complaint - when he does stretch his legs, the result is wooden crap.
Slashdot Mirror
That only happens if you have been stupid! If you live within your means, the chances of these problems drops dramatically.
Asking people to live within their means and excercise common sense is hardly 'reliance on perfection'. In fact, until very recently in the West it was considered common and desireable to live within ones means - and society very decidely didn't get ruined by centuries of this.
So? Putting bills on credit cards makes things worse.
Sorry, no. Babies don't 'just happen'. Just like bad credit *you* have to take deliberate action for it to happen. (And modern birth control very, very, very rarely fails. Use birth control and don't have sex during the females fertile period and the odds of something 'just happening' drop to essentially zero.)
Right. That's why people lived for centuries in hot climates without air conditioning. The problem isn't lack of air conditioning - but lack of conditioning themselves for hot weather.
Hardly. Protein != meat. It's quite possible to have a meatless diet and to quite healthy.
No, it relegates the stupid to permanently poor status - because if you are poor, you are brain dead to run up any significant credit card debt. Heck, even if you aren't poor, it's stupid to have any credit card debt.
Certainly that is true - but there does come a point of diminishing returns. If the database that drives Target's website doesn't have a field for the alt-text - then the database has to be redesigned and the data converted over. Then someone (actually a lot of someones) has to create and enter the text for thousands of products - plus the continuing cost of creating and adding it with each new entry. Not cheap! If there aren't enough blind customers to justify this cost - then their vested interest lies in not spending money that can't recoup in a reasonable time.
While that's a popular legend - its false. NASA has never said any such thing.
There are actually two weight limits - the 'safe limit' and the 'safe once' limit. If you have to land with a payload greater than the former, thus being in the 'safe once' zone, then the vehicle has to undergo a series of special inspections to ensure the structure and landing gear was not damaged. (Hubble is in the 'safe always' zone.)
No, I wouldn't expect and overhaul of, or gross changes to, the Big Bang theory - but when a prediction made by the theory fails to pan out, it needs to be explained. Maybe the theory is faulty in the fine details, or an assumption or two is wrong, or the implications of other portions of the theory are misunderstood. This means that, at a minimum, a careful re-examination may be in order. (The first step of course is to rule out a problem with the WMAP probe - in design, construction, or operation. The details of the analysis performed by the physicists of course will also have to be closely examined.)
Or, to put it simply; it's far too early to make any comments about changes to the theory - there are more than a few steps and considerable work to be done, to verify or disprove the results in the [scientific, not news] papers.
Sure. Once you get a nuclear reactor there to provide heat and light - but when the reactor fuel runs out - what then?
You miss the OP's point - reputation isn't made by proving an understanding of the goals, or by contributing articles - it's made by amassing a large number of edits. They key problem with this is that and edit can be anything - even a quick spelling correction earns you a line in your earns you a line in your 'user contributions' log, and creating a new article equally gains you single line...
Which is precisely the primary modus operandi of Jimbo Wales - he cares little for facts or truth, he cares much about his vision. When facts and truth don't fit the vision, they are discarded and ignored in favor of spin.
No, the problems with the Segway itself still would have been place - and price was only one of them. Its still not really compatible with the real word, and its still a 'solution in search of a problem', no matter what the economic conditions are. Possibly, pre dot-bomb, they'd have sold more units - but it still is extremely unlikely to have been widely adopted.
Taking the statute of limitations and tossing it into the trash isn't scary? Reducing the burden of proof the State must provide from the criminal standard to the civil standard isn't scary? Removing the right to trial by the jury of ones peers isn't scary?
Just how thoroughly do the protections built into our legal system have to be trashed to scare you?
That assumes that the process is in fact practical - elegance != practical. Even if it is practical, you don't eliminate as much as of Galactica effect as you might think - the reactor and processing facility is still going to be large and heavy (and difficult to land), not to mention the large (and not so heavy) tanks to store the produced fuel. Not to mention the difficulty of getting all the units hooked up once on the Martian surface. The proposal also introduces an additional complication in that you must land your return vehicle, rather than leaving it in orbit - which places some significant design contraints and potentially adds failure modes. (Not to mention the fact that they return vehicle, even though its 'fluffy' at that stage, is a large and difficult-to-land component in its own right.)
As I said, no obvious showstoppers - but once you actually start digging into the details its unclear that in situ fuel production is better than more conventional schemes. It removes some hurdles - but it also introduces some new ones.
It is, and it isn't. On one hand, very little about Lunar suface operations can be directly and usefully transferred to Martian surface operations. The environments of the two are simply too radically different. OTOH, a Lunar base is not much different (conceptually) from Apollo's 8-9-10 in the it provides valuable operational experience for the Mars mission itself. (Not just orbital experience, but ground processing, planning, etc... etc...)
If you are serious about going to Mars, the ISS or something like it is a vital component of the program. A Martian mission will spend most of its time in the cruise phase - in weightlessness. Thus we need to study the long term effects of weightlessness and determine whether or not a heavy (and complicated and expensive) centrifuge system will be required. We need to study and qualify the life support system, which will have to work for years on end. Ditto for items such as the computers, science equipment, logistics provisioning, etc... etc.. I agree, ISS isn't doing this very well at the moment, nor is it planned to, but it can be made to fill that role.
Actually, we need to do detailed basic research followed by detailed design and trade-off studies on both concepts - then and only then can we make a rational choice between the two. It's not clear that in situ fuel production will be better than envelope expansion on more conventional, and existing, methodologies.
Unfortunately, what 'seems' practical may or may not be once you get down to the nitty-gritty details. Assuming that because it 'seems' more practical, especially with the utter and complete lack of evidence that it is more practical, that it must be 'the way to go - is a fast way to potentially end up in a very deep hole with a lot of money spent and nothing to show for it but a negative result.
I know there is a lot and handwaving and 'but on the gripping hand' in this reply - but that's the nature of the subject matter. We simply don't have enough information on either option to make a clear black-and-white call. We may never be able to render it thus, and be placed in the position of rolling the dice with little more than knowing the odds to some unknown degree of precision.
I'm glad to see that most Slashdotters are financially independent - or in a situation (like living in a relatives basement) where having money is irrelevant. I can see no other reason why most of the advice to date boils down to 'quit your job and run'. Few people outside of Slashdot are in such a happy position I suspect.
The problem is - Zubrin's cleverness and and ability at analysis is matched by his overconfidence in the products thereof. He has a strong tendency to treat his ideas as if they were simple solutions with no real development needed, ready for deployment fairly easily - when the truth is that they are anything but. His Nuclear Salt Water Rocket for example has never been modeled, and only examined on the theoretical level at the grossest of scales. Yet he, and his disciples, treat it as if it were mature technology ready for use with only a few tweaks. The same is true of his scheme for producing fuel in situ on Mars. No developmental work has been done, and very little basic research - yet he argues it convincingly enough that many people assume (as does the poster you are replying to) that its a 'done deal'.
The Case for Mars *is* a feel good read - but that's about all it is. It's much close to fiction than reality. The 'truck driver' schemes keep coming up - because they are (in the main) something that can be accomplished by working within the bounds of existing or near term technologies (the GP vastly overstates the case), while Zubrin's are almost completely undeveloped and are at or beyond the bleeding edge.
This process has never been tested beyond the laboratory workbench. There are a large number of very significant hurdles to getting such a system operational on the Martian surface. Among them - insulation; Mars has enough atmosphere that MLI won't work, and this means large, bulky and difficult to handle tanks for receiving the output product. Another is filtering the input feed (to get rid of the atmospheric dust), as well as keeping the filters themselves clean. Etc... Etc... No obvious showstoppers I admit, but some very definite steep hurdles.
Many people have read The Case For Mars - many of those have gradually come to understand how much of that book is smokescreens, handwaving, and wishful thinking. Robert Zubrin has a very bad habit of assuming that coming up with clever schemes means that implementation is a simple straightforward thing - even when they represent quantum leaps over existing technologies.
You are pretty much stuck on this rock then - because there isn't such a company in existence today. *Nobody* has any current experience in designing manned spacecraft. Even the Russians limit themselves to modest modification to their existing craft - it will be very interesting to see how Kliper plays out (assuming it ever gets built).
You must have last heard back in the 50's or so.
The solution has been known for decades - provide a 'storm cellar' to take refuge in during these (fairly rare) 'storms' (flares), using your potable and waste water tanks for shielding. It's fairly straightforward within the limits of our current knowledge. Day-to-day radiation exposure will be somewhat higher than current safety limits, but barely enough to be 'serious' let alone 'deadly'. (Me, I'd take the 10-15% greater chance of inducing cancer if I were still in a position to have a chance at a berth on a Mars bound ship.)
Because this contract covers mostly the LEO and Lunar phases of the missions, it's pretty pointless to handwave and play Chicken Little about the Martian phases.
Before taking the submitters/editors to task - you yourself should get your facts straight. This contract is for the Orion CEV - analogous to the Apollo CSM. It won't land on either the Moon or Mars - it's an orbiter.
No, it really doesn't. Half life determines the rate of voltage decay - but it doesn't determine the lowest voltage at which the system(s) will operate. You can have a RTG with a half life of two centuries - and still have a dead probe after twenty years. You can have an RTG with a half life of fifty years - and have a probe operating for forty. Half-life is only a very misleading portion of the story.
And? RTG's decay at a fixed rate - regardless of how much power is drawn. If you have acess to the original specs you can calculate how long the ALSEP is likely to have remained active (based on power levels).
Again, correct but misleading and incomplete. Unless you are *really* low, the nightside shadow only lasts half an hour or so - not enough time for a properly designed spacecraft to cool down significantly. OTOH - Lunar night is more than low enough for everything unheated in the ALSEP package to drop down to cryogenic temperatures. These cooling and heating cycles place a great deal of stress on connectors (not all of which on the ALSEP were heated) and on the insulation materials used.
So? I've seen equipment that operated just fine for over a decade up and die - all lasting eight years means is that the equipment lasted eight years. That figure has no predictive power whatsoever.
It's not the half life that matters - it's when the output voltage drops below a useable value. The half life of the RTG's on the Voyager probes is comparable - but they had to start turning off instruments years ago, and the RTG is expected to stop producing sufficient power to operate anything in the next five years or so. Furthermore, the environment on the Lunar surface is extremely harsh, much harsher than that the Voyagers are exposed to. (Mostly due to the large temperature swings on the Moon. The Voyagers are colder, but the temperature is steady.)
Your original claim was that the themes echoed throughout Heinlein's work - I never claimed anything about your examples beyond pointing out that they failed to support your initial claim.
No, I said they did not echo, as you implied, through all his works. Your own examples bear out that I am correct.
I didn't mock Robinson - but made a critical statement of his authorial capabilities. (And one not original with me either, it's a fairly widely held one. There's a reason why Robinson has dropped off the best seller lists you know.) Drop by your local bookstore and read the back cover of his "Very Bad Deaths " and you'll see a prime example.
In other words - we are both wrong. Because he was defeated by being tackled, even if it was the heckling that opened the opportunity.
You don't want your words examined closely - then don't utter them in public.
I have no need of questioning them - you prove your lack of them each time you write. Your original claim was that the themes you quote repeated through 20 books (though his actual total is over 50). Yet above, you identify only seven books, and one short story. One (talking like 30's gangsters) is demonstrably not present in 'Every Heinlein book that there is'. Another, 'convince a bad guy to give up because of logical fallacy' is patently absent from the short story. (He gave up because his 'army' had been defeated and the station he had gained control of had been cut out of the control circuits.)
If there is a pretender in this conversation - it is not I.
"Friday" is his best known work from the 80's because its essentially the only readable work of his from that period. The 'sex scenes' are a very minor proportion of the total book - anyone who focuses on them is an individual with very deep problems. (Or who lacks the wit to examine and discuss the larger issues inherent in the book. Or wishes to avoid doing so because of the depth and difficulty of doing so. I suspect the latter is the real reason, as Heinlein didn't write simple easy-to-categorize books.)
It is a bad thing - because the story outline was prepared in the 50's and thus is most likely intended to have been written in style of his [Heinlein's] 'juveniles' or his short stories of that time. By the 60's his style had changed considerably.
The key difference being that it took RAH thirty years - while it took Spider a little over a decade, to 'lose it'. RAH's 'out there' books are a scant handful out of nearly sixty, while for Robinson its well over half of thirty. (I agree "God is an Iron" ranks in the all time greats.)
I remember 5-10 years back on alt.callahans, Spider complaining (via a proxy) about the poor sales of a collected version of the first three Callahan's books. My response was "what the hell did you expect Spider? It's not like they've been out of print or haven't been available".
That's my complaint - when he does stretch his legs, the result is wooden crap.