Well, then you haven't read the right reports, or lack the wit to comprehend them. (Especially when you make a bullshit claim like 'NASA publishes hundreds of tech reports a year on radiation shielding', I vote for the latter.) Because the techniques I listed are well known ones.
Then there's the case of my 'Uncle', who was actually my cousin... adopted by my grandparents after my aunt celebrated VJ Day a bit enthusiastically and then was sent to live with some distant relatives for a few months.
Just because there is no provision for returning to the Earth doesn't mean we cannot send as much help for survival as we can. Equipment and supplies to build structures, process waste water and grow food, generate power (nuclear, fusion, etc). Plus, if they could survive for a year or two, unmanned resupply missions could be sent out at regular periods
Which means at the end of the day that you've spent as much money, if not more, as if you'd provided for return capability in the first place.
until self-sustainability of the population on mars is established.
I.E. you're speaking in terms of multiple decades.
If they asked, I'd go in an instant.
Tell you what, lock yourself in a room for a year with no internet and no broadcast or cable entertainment. Then come back and talk to me. (Or to put it less generously, the only people volunteering are those who have no fucking clue what they are actually volunteering for.)
The real problem is radiation exposure. 6 months there, 500 days on the surface, 6 months back. Any astronauts you send will never fly in space again and may have trouble getting x-rays for medical problems in the future.
Of course, those guidelines come from a radiation exposure standard whose first line is "Thou Shalt Not be exposed to any more radiation than will have a probability of greater than 1x10^-9 of causing a single additional cancer death". That the standard can be relaxed somewhat with little additional risk is putting it mildly.
Assuming of course the astronauts aren't already considered radiation workers, in which their standards are already relaxed from that of the general public, and can still be relaxed further.
The only known solution to this is to make the habitat module more massive.. which of course requires more fuel...
Actually, the known solutions include a) putting the habitable volume inside the fuel tanks, b) putting the habitable volume inside the storage spaces (food, water, spares) and, c) some combination of all of the above.
From TFA: "Now BBC reports that scientists have used next generation sequencing technology to produce a far more direct and reliable estimate of the number of mutations by looking at thousands of genes belonging to two Chinese men who are distantly related, having shared a common ancestor who was born in 1805."
The cynic in me asks how they made sure they were actually related. It's not precisely unheard of for a woman to stray and for a man to raise a child not his own.
I'm happy to read that SpaceX will be taking over resupply.
SpaceX isn't taking over anything - because SpaceX hasn't the capability to perform resupply.
SpaceX will provide resupply at some uncertain date in the future, *if* they can get Falcon 9 off the ground and and flying reliably, and *if* they can get their delivery vehicle operating and certified, and *if* they don't drive themselves into bankruptcy in the process. (Musk's pockets are deep, but not limitless.) There's a lot of "if's" between today and cargo on orbit.
We should encourage private launch companies. Having NASA handle all launch needs was putting all our eggs in a single basket, and killed any chance for private launch.
In a world where NASA handled all launch needs - that would be true. Here in the real world, private companies like Boeing and Lockmart (and others) have been providing private launch services for decades.
It's already expensive and hard to develop a new space launch system; to do it when NASA is offering launches at cut-rate prices was impossible. (NASA has always been embarrassed by how expensive the Shuttle actually was, and never charged anywhere near a profitable amount for flying things on the Shuttle.)
NASA offered a limited number of cut price rides on the Shuttle for about five years - over twenty years ago. The minor impact of that and the handful of DoD missions where the DoD used the Shuttle instead of buying a booster from private industry, is long over.
Once we have several private companies flying things to orbit, we can expect the cost to orbit to come down drastically.
We have no fewer than three private companies flying things to orbit in the US alone - Boeing, Lockmart, and Orbital Sciences. Prices to orbit haven't noticeably budged.
The DOD, as well as FEMA, should be pushing to have several built for the America. This would actually enable more private launches, but also give the DOD a means to bring energy into areas that they need. Transportation of fuel is EXPENSIVE. The ability to bring power into a hurricane hit area will enable quick power.
Why, exactly, is the transport of fuel "EXPENSIVE" while you seem to think the transport of the components of the receiving array (and the construction equipment required, and the fuel it will require, as well as all the other support) won't be? And how, exactly, is this reception array going to power an area where the electric infrastructure has been shredded? By the time you've got sufficient infrastructure to distribute the received power over a useful area, you've got sufficient infrastructure built to just hook up to the undamaged portion of the national grid.
More importantly, the ability to beam energy will have to be developed. That would enable many of our construction and open pit mining vehicles to move off diesel.
Assuming we figure out how produce enough magical fairy dust each year to form the electrolyte for the batteries those vehicles will require.
Couldn't they just use a winch with the cable fed through a pair of rollers with brakes on them to keep the cable from piling up in the winch?
So what happens to the loose end of cable at the far end? Remember there's no gravity to keep things tidy. (Just the release of tension when one unit disengages from the cable can cause some nasty effects.)
Or reel it in from both ends while its still spinning (to keep some small amount of tension on it) and apply counter-spin thrust to keep the RPMs constant as radius decreases?
So long as both vehicles involved accurately know their distance from the barycenter, can accurately (to within less than 1 FPS) throttle their RCS, and have thrusters that only produce a vector in the desired direction (rarer than you might think)...
Granted none of this seems trivial, but not does it seem that difficult.
It never seems difficult to the armchair engineer.
Even though they aren't directly interested in generating 'G' forces, they all suffer from the same problems outlined in my original post WRT deployment, retrieval, and maneuvering with the tether deployed.
No matter, the Japanese space program proposed a module that would allow the study of incremental gravity on mammals, everything from low gravity to three times earth gravity
Why (not) on Earth would you want to simulate >1g in space? Anything below 1g, sure, but for greater you could just use a centrifuge on Earth where it doesn't take 1000kg of propellant to get every kilogram of payload to your test apparatus.
When performing a related set of experiments, it's generally good science to conduct all the experiments on identical equipment under identical circumstances. A low G (3G) centrifuge on the earth's surface won't produce [simulated] gravity purely in the plane of rotation like one in orbit will - there'll be a vector produced by the earth's gravity. Presumably the scientists who thought up the experiment thought this to be important and worth the many limitations involved.
Many SF fans prefer such an interpretation - because it makes SF glittery and shiny and oh so much different from the plot devices of every other genre. It's a little ray of sunshine into the nerd ghetto, a little beacon of hope.
It's also bullshit.
Full Disclosure: I'm a fan on Niven's earlier works and especially his shorts. By the early 80's he was on the skids, and by the early 90's it was all over. All that booze I suppose.
Or rather Larry Niven invented a plot device to create the Belter culture... And of the hundreds of plot devices that he invented, one happened to be somewhat correct.
Using acceleration to counteract undesirable effects of microgravity appears to be a universally ignored solution.
It's not ignored - it's turned out to be devilishly difficult to arrange.
Back in the Gemini days they actually bothered to join a pair of spacecraft together and spin them up. The effect was about 1000th of a g, but it was a successful mission. Everyone presumed that NASA would continue this research after Apollo, with longer tethers and slower rotation, a 1g environment could be created.
Everyone who? Because everyone I know is familiar with the problems with those tethers bring with them.
Its extraordinarily difficult to stop and start the rotation. Its difficult to avoid tension problems during payout, it's REALLY difficult to prevent snarls during retraction. It's extraordinarily incredibly difficult to make orbital corrections while tethered and spinning...
Until someone comes up with some engineering solutions to test (and they are working on them and two tether deployment tests (both failures) have flown on the Shuttle), any experimentation is moot - kinda like sticking your finger into boiling water to see if it burns you.
Actually, he doesn't have to be smarter than legions of physicists and engineers.
Actually, yes he does - because this gravity tractor has been intensely studied for some time. As indicated by this link prominently provided right in the article, had you bothered to read it.
Therefore, changes are he only has to beat a board of executives who knows nothing about physics or science (on average) who have been given a high level executive summary of this great idea that they should invest in and how it can both lead to a better world (not being smashed up by said cosmic nasty) and possibly making a good deal of money based on their investment
Had you bothered to read the article linked in the summary you'd have noted the scientists work for EADS Astrium - one of the worlds leading aerospace companies. (Assuming of course you are familiar enough with the world of aerospace to know the leading companies.)
Seeing as this company has "decided to create a gravity tractor ship", I wouldn't be surprised at all if there hasn't actually been a surprisingly LACK of physicists and engineers involved at this point in time.
I think I've adequately demonstrated that you haven't a clue what you are talking about. Your opinion are irrelevant, uninformed, and meaningless.
shockwaves that make it through the space between a helmet and a soldier's head
Either Jarhead isn't wearing his helmet properly or there IS a major flaw in the design.
Or maybe you don't know what you are talking about.
Have you ever worn a bike helmet that was 3 sizes too large? How effective was it?
Apples and anchovies. Other than belonging to the same general class of 'helmets', these two types have little to do with each other as they have widely divergent design goals. A bike helmet is meant to protect against abrasion and strong impacts - a soldier's helmet is designed to resist penetration, create ricochets (I.E. divert incoming projectiles), and absorb impacts major and minor *while remaining comfortable to wear for extended periods*.
Additionally, a bicycle helmet and a hard hat can be designed to be essentially disposable... You have an accident, you go get a new helmet. A combat helmet has to remain functional for extended periods despite suffering damage - you can't stop in mid battle to go down and buy a new one.
While a bicycle helmet three sizes too large would be ineffective, a soldier's helmet three sizes too large still provides the considerable protection against the threat(s) it's designed against
If the helmet has an inch of gap, its no surprise that helmets are hitting troops with more effective damage then if they were wearing nothing at all.
On the other hand, the gap was added because it made the helmets more comfortable - and protective gear that is more comfortable to wear is protective gear that's more likely to be worn. (Manufacturers and designers of soldiers combat gear, hard hats, and motorcycle helmets have been struggling with that balance for years.) You see the same thing in the construction worker's hard hat, it sits above the head for ventilation, rather than close to head. The additional gap (in both) also allows the suspension to absorb and diffuse shock from minor impacts and ricochets.
If your casual biker was required to wear a helmet for extended periods for work, rather than for relatively short periods as desired for fun, you can bet your bottom dollar they'd be designed differently. *Way* differently.
I, for one, am getting really fed up with people trying to get in the way of Google, and others making more information available, for free.
And Google just loves people like you - because they can get away with the most outrageous acts and the apologists will rush to bleat their support. They don't need to astroturf, they don't need Brownshirts - synchophants like you will blindly rush to defend them without them raising a finger.
There is a huge difference between protecting the public right to privacy, as has recently ocured here in Switzerland and this endless carping by libraries and copyright holders about orphaned books etc.
If we are serious about scholarship in the internet age we must do something similar, allow google and others to scan and index books provide short extracts free for fair use while selling complete electronic copies through retailers. The same for learned journals.
Which is exactly the point... Google is not a hero in this case - they're trying to rig the game such that they and only they have an exclusive, monopolistic, right to make information available. The 'and others' will be unable to do so because Google has arranged for an organization to 'settle' with them and provide Google with rights that its unclear the organization has the legal authority to convey in the first place. It's as if Google broke into your neighbors house, was then sued by some random guy across town, and then they 'settled' by giving Google clear title to the neighbors land.
And yet most governments go along like "Oh really we did something wrong? Well that wasn't my fault that was someone else. I'd never do that to you." Oh really, then why don't you just apologize and get on with life? What, no apology? Gee, I guess you don't think it was wrong huh?
Why should a group that didn't so something apologize to a people they didn't do it against?
Unless they want to be sued, as well as losing some popular attractions, they'll stick to their contract - I.E., yes they will continue paying. Why is this even a question?
Slashdot Mirror
Well, then you haven't read the right reports, or lack the wit to comprehend them. (Especially when you make a bullshit claim like 'NASA publishes hundreds of tech reports a year on radiation shielding', I vote for the latter.) Because the techniques I listed are well known ones.
Incest isn't exactly unknown.
Then there's the case of my 'Uncle', who was actually my cousin... adopted by my grandparents after my aunt celebrated VJ Day a bit enthusiastically and then was sent to live with some distant relatives for a few months.
And what makes you think we don't know what does and doesn't block radiation and by how much?
Reading comprehension, get some. I didn't say we couldn't do it, I said we couldn't do it now.
We already know the answer to that: Currently, we can't. After a decade or so of R&D and few tens of billions of dollars, we might be able to.
Which means at the end of the day that you've spent as much money, if not more, as if you'd provided for return capability in the first place.
I.E. you're speaking in terms of multiple decades.
Tell you what, lock yourself in a room for a year with no internet and no broadcast or cable entertainment. Then come back and talk to me. (Or to put it less generously, the only people volunteering are those who have no fucking clue what they are actually volunteering for.)
Of course, those guidelines come from a radiation exposure standard whose first line is "Thou Shalt Not be exposed to any more radiation than will have a probability of greater than 1x10^-9 of causing a single additional cancer death". That the standard can be relaxed somewhat with little additional risk is putting it mildly.
Assuming of course the astronauts aren't already considered radiation workers, in which their standards are already relaxed from that of the general public, and can still be relaxed further.
Actually, the known solutions include a) putting the habitable volume inside the fuel tanks, b) putting the habitable volume inside the storage spaces (food, water, spares) and, c) some combination of all of the above.
And your qualificatione for shaking your head are what?
Too many hours spent watching Star Trek and/or having an overactive imagination don't count.
From TFA: "Now BBC reports that scientists have used next generation sequencing technology to produce a far more direct and reliable estimate of the number of mutations by looking at thousands of genes belonging to two Chinese men who are distantly related, having shared a common ancestor who was born in 1805."
The cynic in me asks how they made sure they were actually related. It's not precisely unheard of for a woman to stray and for a man to raise a child not his own.
I just love it when people pronounce as impossible something that's been happening for two years...
No, it's about your unclear writing, vague logic, and general disconnect from the facts.
SpaceX isn't taking over anything - because SpaceX hasn't the capability to perform resupply.
SpaceX will provide resupply at some uncertain date in the future, *if* they can get Falcon 9 off the ground and and flying reliably, and *if* they can get their delivery vehicle operating and certified, and *if* they don't drive themselves into bankruptcy in the process. (Musk's pockets are deep, but not limitless.) There's a lot of "if's" between today and cargo on orbit.
In a world where NASA handled all launch needs - that would be true. Here in the real world, private companies like Boeing and Lockmart (and others) have been providing private launch services for decades.
NASA offered a limited number of cut price rides on the Shuttle for about five years - over twenty years ago. The minor impact of that and the handful of DoD missions where the DoD used the Shuttle instead of buying a booster from private industry, is long over.
We have no fewer than three private companies flying things to orbit in the US alone - Boeing, Lockmart, and Orbital Sciences. Prices to orbit haven't noticeably budged.
Why, exactly, is the transport of fuel "EXPENSIVE" while you seem to think the transport of the components of the receiving array (and the construction equipment required, and the fuel it will require, as well as all the other support) won't be? And how, exactly, is this reception array going to power an area where the electric infrastructure has been shredded? By the time you've got sufficient infrastructure to distribute the received power over a useful area, you've got sufficient infrastructure built to just hook up to the undamaged portion of the national grid.
Assuming we figure out how produce enough magical fairy dust each year to form the electrolyte for the batteries those vehicles will require.
So what happens to the loose end of cable at the far end? Remember there's no gravity to keep things tidy. (Just the release of tension when one unit disengages from the cable can cause some nasty effects.)
So long as both vehicles involved accurately know their distance from the barycenter, can accurately (to within less than 1 FPS) throttle their RCS, and have thrusters that only produce a vector in the desired direction (rarer than you might think)...
It never seems difficult to the armchair engineer.
Even though they aren't directly interested in generating 'G' forces, they all suffer from the same problems outlined in my original post WRT deployment, retrieval, and maneuvering with the tether deployed.
When performing a related set of experiments, it's generally good science to conduct all the experiments on identical equipment under identical circumstances. A low G (3G) centrifuge on the earth's surface won't produce [simulated] gravity purely in the plane of rotation like one in orbit will - there'll be a vector produced by the earth's gravity. Presumably the scientists who thought up the experiment thought this to be important and worth the many limitations involved.
Many SF fans prefer such an interpretation - because it makes SF glittery and shiny and oh so much different from the plot devices of every other genre. It's a little ray of sunshine into the nerd ghetto, a little beacon of hope.
It's also bullshit.
Full Disclosure: I'm a fan on Niven's earlier works and especially his shorts. By the early 80's he was on the skids, and by the early 90's it was all over. All that booze I suppose.
Or rather Larry Niven invented a plot device to create the Belter culture... And of the hundreds of plot devices that he invented, one happened to be somewhat correct.
It's not ignored - it's turned out to be devilishly difficult to arrange.
Everyone who? Because everyone I know is familiar with the problems with those tethers bring with them.
Its extraordinarily difficult to stop and start the rotation. Its difficult to avoid tension problems during payout, it's REALLY difficult to prevent snarls during retraction. It's extraordinarily incredibly difficult to make orbital corrections while tethered and spinning...
Until someone comes up with some engineering solutions to test (and they are working on them and two tether deployment tests (both failures) have flown on the Shuttle), any experimentation is moot - kinda like sticking your finger into boiling water to see if it burns you.
Actually, yes he does - because this gravity tractor has been intensely studied for some time. As indicated by this link prominently provided right in the article, had you bothered to read it.
Had you bothered to read the article linked in the summary you'd have noted the scientists work for EADS Astrium - one of the worlds leading aerospace companies. (Assuming of course you are familiar enough with the world of aerospace to know the leading companies.)
I think I've adequately demonstrated that you haven't a clue what you are talking about. Your opinion are irrelevant, uninformed, and meaningless.
Ah yes. As always, the random Slashdot poster is smarter and knows better than whole legions of physicists and engineers.
Or maybe you don't know what you are talking about.
Apples and anchovies. Other than belonging to the same general class of 'helmets', these two types have little to do with each other as they have widely divergent design goals. A bike helmet is meant to protect against abrasion and strong impacts - a soldier's helmet is designed to resist penetration, create ricochets (I.E. divert incoming projectiles), and absorb impacts major and minor *while remaining comfortable to wear for extended periods*.
Additionally, a bicycle helmet and a hard hat can be designed to be essentially disposable... You have an accident, you go get a new helmet. A combat helmet has to remain functional for extended periods despite suffering damage - you can't stop in mid battle to go down and buy a new one.
While a bicycle helmet three sizes too large would be ineffective, a soldier's helmet three sizes too large still provides the considerable protection against the threat(s) it's designed against
On the other hand, the gap was added because it made the helmets more comfortable - and protective gear that is more comfortable to wear is protective gear that's more likely to be worn. (Manufacturers and designers of soldiers combat gear, hard hats, and motorcycle helmets have been struggling with that balance for years.) You see the same thing in the construction worker's hard hat, it sits above the head for ventilation, rather than close to head. The additional gap (in both) also allows the suspension to absorb and diffuse shock from minor impacts and ricochets.
If your casual biker was required to wear a helmet for extended periods for work, rather than for relatively short periods as desired for fun, you can bet your bottom dollar they'd be designed differently. *Way* differently.
And Google just loves people like you - because they can get away with the most outrageous acts and the apologists will rush to bleat their support. They don't need to astroturf, they don't need Brownshirts - synchophants like you will blindly rush to defend them without them raising a finger.
Which is exactly the point... Google is not a hero in this case - they're trying to rig the game such that they and only they have an exclusive, monopolistic, right to make information available. The 'and others' will be unable to do so because Google has arranged for an organization to 'settle' with them and provide Google with rights that its unclear the organization has the legal authority to convey in the first place. It's as if Google broke into your neighbors house, was then sued by some random guy across town, and then they 'settled' by giving Google clear title to the neighbors land.
Why should a group that didn't so something apologize to a people they didn't do it against?
Unless they want to be sued, as well as losing some popular attractions, they'll stick to their contract - I.E., yes they will continue paying. Why is this even a question?