Also, NASA used cryogenic propellants for many manned missions.
Cryogenic fuel and oxidiser loading was complete before the astronauts entered the capsule or the Shuttle. Some extra LH2 and LOX was added as a top-up process during the rest of the countdown due to losses from warming.
SpaceX's ultra-cold higher-density LOX has to be loaded almost immediately before launch as it will warm up and expand and negate the advantage of its increased density if it's left too long in the rocket's tank. That requires astronauts on a man-rated Falcon 9 using higher-density LOX to be on board the capsule when the oxygen tank starts being filled. This is an extra risk over and above all the other risks of flying the cheapest bidder's hardware.
There are additional problems. It means that once the fuel is loaded there is a limited window to finish final checks and make the "go" decision. The "hold" time must be pretty short - but I have not seen a quote on how long it is. And that means if there is any unexpected delay in the launch after loading the mission must be scrubbed entirely, the astronauts must be taken off, and the fuel unloaded again. This also cuts into the purported advantage of being the low cost bidder if any launch hold results in a complete scrub (it is a hidden additional cost).
You don't load densified fuel unless the mission requires it, as reusing the launcher apparently does. So apparently the argument is that the astronauts need to be exposed to risk so that SpaceX can recover their launcher, thus lowering launch costs.
Maybe, just maybe, when crews are launched the launcher should be expendable.
Good idea. Uranium is only $30-40 per pound too. A pound of Uranium would power a car for about a year. The only problem is that the device is larger than a human, but I am sure they can shrink it down to something much smaller. After all, computers used to fill a room and now my wristwatch has more computing power than those did!
You need enriched uranium - enough to make a critical mass. The 10 KW Kilopower unit for KRUSTY requires 75 kg of weapon-grade U-235 (93%). This is a the better part of a million dollars worth.
One pound of natural uranium, or pure U-235 for that matter, will not power anything at all. The scaling for nuclear reactors bears no relation to miniaturization of electronics, and the necessary sizes were fixed by physics about 70 years ago and have not changed since.
There's multiple companies already selling 100KW and Megawatt scale regional pwer plants to bury in the ground. TOshiba. Hyperion.
No there aren't. Not one of these proposed systems has yet been brought to market. Here is an up-to-date page from the World Nuclear Association outlining all of the existing reactors and companies proposing small reactor units. Multiple companies have made proposals, none of which exist as products.
It appears that multiple non-ACs here read highly optimistic schemes, oh about 8 to 10 years ago, and assumed that these schemes actually bore fruit on schedule - and are now lying here about having actual knowledge of these units in operation, which in truth do not exist.
Odd. There should be more articles about neighborhoods that have buried nuclear reactors. They are everywhere.
In which case you should have no trouble coming up with an actual link. Or the name of an actual company. Or the location of one of these units. Or anything beyond a completely contentless assertion.
None of the linked articles really support the idea that there is insufficient suitable sand on a global scale (though maybe there is). All of the articles describe local sand shortages, and the fact that unscrupulous types are taking it from the most accessible sources - beaches. None of the articles have any estimated of global reserves and how this relates to demand for concrete.
Captain Pedantic gets two demerits. The source of the CO2 production in the production of concrete IS from that ingredient called "cement". Sand, aggregate and water contribute nothing to CO2 release.
as far as I can tell, this summary is blaming concrete because the energy source is dirty. What if the energy came solely from turbines, dams, nuclear power, or some other form of clean energy?
Fossil fuel combustion is only part (40-50%) of the problem with making cement. The other part, 50-60% is this chemical reaction: CaCO3 -> CaO + CO2. The calcium oxide produced is a key part of cement. Not using fossil fuels would cut CO2 emission by about half, but is not a complete solution to the problem.
Actually cement - over the course of decades - reabsorbs about 40% of the CO2 released by the burning of limestone as it post-cures. So the net CO2 release from concrete is commonly overstated by about 20-25%, and the net contribution of fossil fuel is more like 55-65% of total net CO2 release.
There was a recent item about carbon capture with peridotite (but I am linking to an older story about it). Peridotite exists in huge surface formations in several areas of the world.
Perhaps an additional stage could be added to cement manufacture wherein the CO2 released is passed through a second kiln loaded with quarried peridotite to capture the CO2, producing calcium carbonate (again). Since calcium carbonate (limestone) is a starting material processed in the first kiln it could possible be recycled to make more cement. This would mean that you would build the plants near peridotite deposits, and import only a starting amount of calcium carbonate to the site.
Indeed it is nothing new. It is predictable as anything. It even has a term used by the U.S. intelligence agencies LOVEINT.
If you follow the news you will be aware that every organization that maintains records on private individuals, or has access to surveillance systems, will have some percentage of staffers using it titillate themselves, or stalk others. Spying on calls with loved ones from U.S. servicemen deployed overseas, the NSA staffers trading naked pictures, police looking up information on people they have interests in, etc., etc.
Considering that the 2017 annual US tax revenue is $1.9 trillion, calling 6 trillion dollars of debt means big problems for the US.
According to that link annual US tax revenue is $3,340.4 trillion. Income tax is not the only Federal tax revenue as that table makes painfully obvious.
But your point is well taken, it is a good thing that the Republicans cut tax revenue further in December so that debt well pile up even faster. MAGA!
This is an example of someone so trapped in an ideological bias that they insert things they imagine must be true into what they read.
Bantling did not get $1.00 per shot (which is what you presumably imagined), but $1.00 total, or the princely sum - accounting for inflation of $14.85 in 2018 money.
Ubiquitous cameras, social media, the web generally, facial recognition software and unlimited data storage is stripping anonymity away from everybody.
Combine that with data bases on everybody (cough - Facebook - cough - Google - cough) and it becomes impossible to maintain a 'legend'.
It makes sense that it is making old-school cloak-and-dagger work obsolete.
But lots of glass artifacts would be dropped into contexts were they are efficiently preserved, just like the fossils we find. Indeed just like fossils, we would have many casts of all manner of manufactured articles, it they existed.
According to other, other real research plastics can survive for 320 million years. We know because we have samples that old. It is a natural plastic called "amber". We have many synthetic polymers now that are far, far more resistant to deterioration than amber.
" The fact they they failed to do something about the incoming asteroid"
ROFL. What could WE do about it?
With enough lead time, we could do plenty. The Chicxulub asteroid was about 10 km in diameter, or about 500 cubic km, and had a mass of a few trillion tonnes.
Quite true. We really don't have to worry about any asteroid on the scale of the KT Killer - we are already tracking all asteroids of this scale that could possibly intersect Earth's orbit.
Unfortunately about 20% of this threat is from long-period comets which we will only see a couple of years before impact. Remember Hale-Bopp, the great comet of 1997? It was 60-80- km across, or 200 to 500 times more massive than the KT Killer! It was also a "new" comet, making its first approach to the Sun.
Good point, but a poor choice of material. Coal is a super-abundant resource, even massive ancient exploitation would have left enormous amounts behind. Burning all coal would produce a CO2 level of some 5000 ppm, the highest it has ever been in the past (about 150 million years ago) was half this.
Much scarcer materials like many metals are much better evidence for no prior exploitation.
Depends on when you think this supposed pre-human technological civilization occurred. The farther back you suppose, then the more the Earth's surface will have altered.
The point is that we are now tunneling deep into the Earth, having already exploited rich easy to reach supplies. Sure, over geologic time uplift and erosion change which deposits are near the surface, but whatever collection of ore deposits these may be, once they are gone then tunneling and massive disruption of ancient ore deposits ensue. If there was a prior technological civilization then these deep mines would be in many places. We have yet to find one.
Perhaps it should now be downgraded to "The Good Barrier Reef". Eventually it will inevitably become the "The Fair Barrier Reef" and ultimately "The Poor Barrier Reef".
Why does anyone fall for this anymore? There was some survey recently where more than 80% of ICOs were scams.
When you combined the major fraction which are straight-up scams with the majority of the non-scams that nonetheless fail, your chances of ending up with nothing was 92%, and of the remainder the only criterion was that you weren't left with nothing. Your odds of actually making a profit, or breaking even, were roughly the same as getting double boxcars on one throw of a pair of dice.
Most likely there are people who see the job very differently from the author. For everyone paid less or fired for being slow, there is someone else willing to hustle, and getting paid more.
Because in Libertarian World there are no bad working conditions, only lazy employees who are not sufficiently grateful to the 'job creators' for giving them 'opportunity'. Dead end job? No such thing!
Slashdot Mirror
Is it technically a "lie" if you believe it because you live in a self-constructed fantasy world?
That is the out that lots of neo-cons (like GF Will and Max Boot) cling to to deny that the Bushites lied us into a war.
The problem with that is that they lied right and left to make their case because their was no credible evidence of their shared delusion.
Just because you believe a false thing is true does not then make the lies you tell to defend that delusion anything other than lies.
I have never like gambling - I played a slot machine once for 15 minutes, and it was one of the most boring 15 minutes of my life.
I also don't like social media (unless /. counts). So apparently I don't have the brain chemistry these addiction-enablers are exploiting.
Also, NASA used cryogenic propellants for many manned missions.
Cryogenic fuel and oxidiser loading was complete before the astronauts entered the capsule or the Shuttle. Some extra LH2 and LOX was added as a top-up process during the rest of the countdown due to losses from warming.
SpaceX's ultra-cold higher-density LOX has to be loaded almost immediately before launch as it will warm up and expand and negate the advantage of its increased density if it's left too long in the rocket's tank. That requires astronauts on a man-rated Falcon 9 using higher-density LOX to be on board the capsule when the oxygen tank starts being filled. This is an extra risk over and above all the other risks of flying the cheapest bidder's hardware.
There are additional problems. It means that once the fuel is loaded there is a limited window to finish final checks and make the "go" decision. The "hold" time must be pretty short - but I have not seen a quote on how long it is. And that means if there is any unexpected delay in the launch after loading the mission must be scrubbed entirely, the astronauts must be taken off, and the fuel unloaded again. This also cuts into the purported advantage of being the low cost bidder if any launch hold results in a complete scrub (it is a hidden additional cost).
You don't load densified fuel unless the mission requires it, as reusing the launcher apparently does. So apparently the argument is that the astronauts need to be exposed to risk so that SpaceX can recover their launcher, thus lowering launch costs.
Maybe, just maybe, when crews are launched the launcher should be expendable.
Good idea. Uranium is only $30-40 per pound too. A pound of Uranium would power a car for about a year. The only problem is that the device is larger than a human, but I am sure they can shrink it down to something much smaller. After all, computers used to fill a room and now my wristwatch has more computing power than those did!
You need enriched uranium - enough to make a critical mass. The 10 KW Kilopower unit for KRUSTY requires 75 kg of weapon-grade U-235 (93%). This is a the better part of a million dollars worth.
One pound of natural uranium, or pure U-235 for that matter, will not power anything at all. The scaling for nuclear reactors bears no relation to miniaturization of electronics, and the necessary sizes were fixed by physics about 70 years ago and have not changed since.
There's multiple companies already selling 100KW and Megawatt scale regional pwer plants to bury in the ground. TOshiba. Hyperion.
No there aren't. Not one of these proposed systems has yet been brought to market. Here is an up-to-date page from the World Nuclear Association outlining all of the existing reactors and companies proposing small reactor units. Multiple companies have made proposals, none of which exist as products.
It appears that multiple non-ACs here read highly optimistic schemes, oh about 8 to 10 years ago, and assumed that these schemes actually bore fruit on schedule - and are now lying here about having actual knowledge of these units in operation, which in truth do not exist.
Odd. There should be more articles about neighborhoods that have buried nuclear reactors. They are everywhere.
In which case you should have no trouble coming up with an actual link. Or the name of an actual company. Or the location of one of these units. Or anything beyond a completely contentless assertion.
Links or it doesn't exist.
Wood? Environmentalists would have a fit...
Nonsense, as long as it comes from wood plantations instead of cutting old growth forests using wood causes no problems.
None of the linked articles really support the idea that there is insufficient suitable sand on a global scale (though maybe there is). All of the articles describe local sand shortages, and the fact that unscrupulous types are taking it from the most accessible sources - beaches. None of the articles have any estimated of global reserves and how this relates to demand for concrete.
Captain Pedantic gets two demerits. The source of the CO2 production in the production of concrete IS from that ingredient called "cement". Sand, aggregate and water contribute nothing to CO2 release.
as far as I can tell, this summary is blaming concrete because the energy source is dirty. What if the energy came solely from turbines, dams, nuclear power, or some other form of clean energy?
Fossil fuel combustion is only part (40-50%) of the problem with making cement. The other part, 50-60% is this chemical reaction: CaCO3 -> CaO + CO2. The calcium oxide produced is a key part of cement. Not using fossil fuels would cut CO2 emission by about half, but is not a complete solution to the problem.
Actually cement - over the course of decades - reabsorbs about 40% of the CO2 released by the burning of limestone as it post-cures. So the net CO2 release from concrete is commonly overstated by about 20-25%, and the net contribution of fossil fuel is more like 55-65% of total net CO2 release.
There was a recent item about carbon capture with peridotite (but I am linking to an older story about it). Peridotite exists in huge surface formations in several areas of the world.
Perhaps an additional stage could be added to cement manufacture wherein the CO2 released is passed through a second kiln loaded with quarried peridotite to capture the CO2, producing calcium carbonate (again). Since calcium carbonate (limestone) is a starting material processed in the first kiln it could possible be recycled to make more cement. This would mean that you would build the plants near peridotite deposits, and import only a starting amount of calcium carbonate to the site.
Indeed it is nothing new. It is predictable as anything. It even has a term used by the U.S. intelligence agencies LOVEINT.
If you follow the news you will be aware that every organization that maintains records on private individuals, or has access to surveillance systems, will have some percentage of staffers using it titillate themselves, or stalk others. Spying on calls with loved ones from U.S. servicemen deployed overseas, the NSA staffers trading naked pictures, police looking up information on people they have interests in, etc., etc.
Exactly my reaction. Once they scan them, they can put them on-line. Done and done.
Considering that the 2017 annual US tax revenue is $1.9 trillion, calling 6 trillion dollars of debt means big problems for the US.
According to that link annual US tax revenue is $3,340.4 trillion. Income tax is not the only Federal tax revenue as that table makes painfully obvious.
But your point is well taken, it is a good thing that the Republicans cut tax revenue further in December so that debt well pile up even faster. MAGA!
This is an example of someone so trapped in an ideological bias that they insert things they imagine must be true into what they read.
Bantling did not get $1.00 per shot (which is what you presumably imagined), but $1.00 total, or the princely sum - accounting for inflation of $14.85 in 2018 money.
Ubiquitous cameras, social media, the web generally, facial recognition software and unlimited data storage is stripping anonymity away from everybody.
Combine that with data bases on everybody (cough - Facebook - cough - Google - cough) and it becomes impossible to maintain a 'legend'.
It makes sense that it is making old-school cloak-and-dagger work obsolete.
But lots of glass artifacts would be dropped into contexts were they are efficiently preserved, just like the fossils we find. Indeed just like fossils, we would have many casts of all manner of manufactured articles, it they existed.
According to other, other real research plastics can survive for 320 million years. We know because we have samples that old. It is a natural plastic called "amber". We have many synthetic polymers now that are far, far more resistant to deterioration than amber.
" The fact they they failed to do something about the incoming asteroid"
ROFL. What could WE do about it?
With enough lead time, we could do plenty. The Chicxulub asteroid was about 10 km in diameter, or about 500 cubic km, and had a mass of a few trillion tonnes.
Quite true. We really don't have to worry about any asteroid on the scale of the KT Killer - we are already tracking all asteroids of this scale that could possibly intersect Earth's orbit.
Unfortunately about 20% of this threat is from long-period comets which we will only see a couple of years before impact. Remember Hale-Bopp, the great comet of 1997? It was 60-80- km across, or 200 to 500 times more massive than the KT Killer! It was also a "new" comet, making its first approach to the Sun.
Good point, but a poor choice of material. Coal is a super-abundant resource, even massive ancient exploitation would have left enormous amounts behind. Burning all coal would produce a CO2 level of some 5000 ppm, the highest it has ever been in the past (about 150 million years ago) was half this.
Much scarcer materials like many metals are much better evidence for no prior exploitation.
Depends on when you think this supposed pre-human technological civilization occurred. The farther back you suppose, then the more the Earth's surface will have altered.
The point is that we are now tunneling deep into the Earth, having already exploited rich easy to reach supplies. Sure, over geologic time uplift and erosion change which deposits are near the surface, but whatever collection of ore deposits these may be, once they are gone then tunneling and massive disruption of ancient ore deposits ensue. If there was a prior technological civilization then these deep mines would be in many places. We have yet to find one.
Nonsense, since 2012 when Dick Cheney had a heart transplant we can finally say with certainty that he has a human heart.
Of course, it was once somebody else's.
Perhaps it should now be downgraded to "The Good Barrier Reef". Eventually it will inevitably become the "The Fair Barrier Reef" and ultimately "The Poor Barrier Reef".
Why does anyone fall for this anymore? There was some survey recently where more than 80% of ICOs were scams.
When you combined the major fraction which are straight-up scams with the majority of the non-scams that nonetheless fail, your chances of ending up with nothing was 92%, and of the remainder the only criterion was that you weren't left with nothing. Your odds of actually making a profit, or breaking even, were roughly the same as getting double boxcars on one throw of a pair of dice.
are people that lazy to find another job?
Most likely there are people who see the job very differently from the author. For everyone paid less or fired for being slow, there is someone else willing to hustle, and getting paid more.
Because in Libertarian World there are no bad working conditions, only lazy employees who are not sufficiently grateful to the 'job creators' for giving them 'opportunity'. Dead end job? No such thing!