I will leave this for the aerospace engineers. Back to newtonian basics, we need thrust, a means to stop, and a reason to do that. My view is that space mining is the key. Rare earth's for type-m and type-s asteroids should render an annuity for everyone on earth, especially, those displaced by automation. Call this a planetary trust fund. Yes, I do expect the ai's will want a cut for all the mining and processing done, so yes, we should keep this in mind.
For travel, I could see a plasma drive that gets derived from our search for fusion- but many disagree. Too heavy, etc...
On Monday, January 17, 2022 Henrik Ohrstrom <everyth...@googlegroups.com> wrote:
You turn the rocket around and as you slow down using BF flashbulbs as you did at takeoff. That's your thruster.
Also grav slingshoting can be used to slow down as well as hurry up.
If you have not played with Kerbal space program, do so now. It is the best way of getting an understanding of orbital mechanics. Then when you are getting cocky, try children of a dead earth. That one is a mouthful even for NASA personel.
/Henrik
Den mån 17 jan. 2022 06:58spudboy100 via Everything List <everyth...@googlegroups.com> skrev:
Clear back in 1974 the British Interplanetary Society did a paper where the ORION effect would be better fulfilled by Daedalus which would detonate thousands of deuterium-tritium pellets using electron beams. Same principle using many micro-detonations. Orion itself gives me the willies, if only because we'd have to stop it in an Newtonian manner, say when Dyson and company arrived to view Saturn's rings close-up. I am thinking of some means of slowing it down, because at fast speed, the gentle Hohnman Transfer Orbits become unavailable. Thus, we'd need thrusters of some kind to slow her down.
Ted Taylor went on to work on solar ponds for providing air conditioning from ice frozen in the winter to provide cooling in the summer. A less grandiose project indeed. For fast interplanetary travel, there needs to be a motivator and yes, your meteorite would do, but mining the Belt seems more sustainable. I am not wedded to any one technology, just one that will work to specification.
-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: 'Brent Meeker' via Everything List <everyth...@googlegroups.com>
Sent: Sun, Jan 16, 2022 4:18 pm
Subject: Re: A gravitational wave rocket
On Sun, Jan 16, 2022 at 3:23 PM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:
> This surely can't be done anytime soon. My suspicion is that new discoveries of profound impact will wait until we can build better equipment, as Freeman Dyson state long ago.
I wrote this a few years ago for another list but as the subject of nuclear space propulsion has come up here and you mentioned Freeman Dyson I thought I'd repeat it:
==
I've been reading a little about an incredible idea taken very seriously in the late 50's and early 60's but today is almost completely forgotten, it was called Project Orion. The idea was to make a spaceship big enough for 150 people and all the equipment they could ever want and blast it into space. They wanted to make it 135 feet in diameter and 160 feet high and they wanted most of that space to be usable by people not wasted on fuel. They figured weight would be no problem, if a crew member wanted to bring along his antique bowling ball collection and his own personal barber chair there would be no objection. The advocates of this approach were not interested in low earth orbit or even the moon, they were certain they could be on Mars by 1965 and Saturn by 1970, the leader of the project was determined to visit Pluto. And they figured all this would cost less than 10% what the Apollo moon project did.
You might think that these people must have been a bunch of crackpots, but it's not so. Nobel Prize winners Niels Bohr, Hans Bethe and Harold Urey were all enthusiastic advocates of the idea. Freeman Dyson thought the idea was so brilliant that he took a one year leave of absence from the prestigious Institute of Advanced Study so he could work full time on the project.
Yes, there is a catch, Project Orion needed nuclear energy, even worse it needed nuclear bombs. The Orion spacecraft would contain 2000 nuclear bombs, most in the 20 kiloton range, the size of the bomb that destroyed Nagasaki. A bomb in a tank of water would shoot out the back of the ship, when it was100 feet away it would explode, the water would hit a carefully designed 75 ton pusher plate and accelerate the ship. Between the pusher plate and the ship were 50 foot long gas filled shock absorbers to even out the jerk. They wanted everything to be as cheap as possible, so they asked the Coca-Cola company for the blueprints of one of their vending machines, then they scaled it up a little and planned to use it as the mechanism to dispense the bombs.
The pusher plate was obviously the most important part of the design. If you explode a powerful bomb near a circular plate of constant thickness it will shatter because of the uneven stresses that build up, but it turns out that if you carefully taper the plate and make certain that the explosion is dead center, the plate will be extraordinarily resistant to damage. A layer on the plate will be vaporized by the heat but if some heavy protective oil is sprayed on it before each use it would be good for 2000 blasts. This beast was tough, if it was properly oriented the Orion Spacecraft could survive a 16 megaton H bomb blast from only two thousand feet away, a fact of more than passing interest to the military. Orion needed lots of radiation shielding to protect the crew, but weight was never an issue so this was no problem.
Wernher von Braun though all this was a dumb idea, then he saw a movie of the launch of a one meter working model of Orion that shot 6 carefully timed high explosives chemical bombs out the back of the model, it rose 300 feet into the air in stable controlled flight. Wernher von Braun became a vocal supporter of project Orion.
"Hot Rod" - Nuclear Orion spacecraft prototype (1959)
They planned to launch Orion from atop eight 250 foot towers in Jackass Flats Nevada. The first bomb would be tiny, just 0.1 kiloton (100 tons of TNT) exploded 100 feet below the craft and 150 feet above the ground, then a new and slightly larger bomb would be spit out the back every second for 50 seconds, the last bomb would be the largest, 20 kilotons, and by then the craft would be out of the atmosphere, the total yield of the 50 bombs would be 200 kilotons. The launch would have been a spectacular sight, it'd make the Space Shuttle look like a bottle rocket.
Project Orion was led by Ted Taylor, a mediocre physicist but a very good inventor. Taylor had one unique talent, he has been called by some the best nuclear weapon engineer on planet Earth and the Leonardo da Vinci of nuclear bomb design. Taylor is the man who figured out how a two foot long 200 pound bomb could be made as powerful as the 12 foot long 10 ton World War 2 Nagasaki bomb. The reason the Orion spaceship was so much bigger and faster than anything we have today is that pound for pound such bombs have about a million times as much energy as any chemical rocket fuel.
Orion wasn't the only thing Taylor was interested in, he found a way to make a new type of nuclear bomb, one that would produce a highly directional blast. He designed a little one kiloton bomb that could blast a 1000 foot tunnel straight through solid rock, he wanted to build a cheap tunnel between New York and San Francisco and have a supersonic subway 3000 miles long.
Considering the big controversy we had when a deep space probe was launched with just a few pounds of non weapon grade Plutonium on it to power the electronics it may seem incredible and irresponsible that anyone would even consider something as environmentally unfriendly as Orion, but we live in a very different world. At the time Orion was under serious study the USA was blowing up one megaton bombs deep under the sea and 300 miles in space and the USSR was blowing up 57 megaton bombs in the atmosphere, Orion seemed and indeed was pretty benign compared to that.
It all came to nothing of course, in 1963 the test ban treaty was signed stopping all nuclear explosions in space or the atmosphere making Orion illegal. The project died, but to this day most say it would have worked technologically if not politically.
Idea for a science fiction novel: A huge nickel iron asteroid is heading for Earth, it would take a 200,000 megaton bomb to divert it but no existing rocket is nearly powerful enough to deliver such a huge payload to the asteroid. The Earth seems doomed, then our hero remembers Project Orion.
John K Clark See what's on my new list at Extropolis
pof
frt
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I will leave this for the aerospace engineers. Back to newtonian basics, we need thrust, a means to stop, and a reason to do that. My view is that space mining is the key. Rare earth's for type-m and type-s asteroids should render an annuity for everyone on earth, especially, those displaced by automation. Call this a planetary trust fund. Yes, I do expect the ai's will want a cut for all the mining and processing done, so yes, we should keep this in mind.
For travel, I could see a plasma drive that gets derived from our search for fusion- but many disagree. Too heavy, etc...
On Monday, January 17, 2022 Henrik Ohrstrom <everyth...@googlegroups.com> wrote:
You turn the rocket around and as you slow down using BF flashbulbs as you did at takeoff. That's your thruster.
Also grav slingshoting can be used to slow down as well as hurry up.
> My suspicion is the motivator [for space mining ] as such will be money sorry to say!
> My view is that space mining is the key. Rare earth's for type-m and type-s asteroids should render an annuity for everyone on earth,
> especially, those displaced by automation
-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: 'Brent Meeker' via Everything List <everyth...@googlegroups.com>
Sent: Sun, Jan 16, 2022 4:18 pm
Subject: Re: A gravitational wave rocketOn Sun, Jan 16, 2022 at 3:23 PM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:
> This surely can't be done anytime soon. My suspicion is that new discoveries of profound impact will wait until we can build better equipment, as Freeman Dyson state long ago.
I wrote this a few years ago for another list but as the subject of nuclear space propulsion has come up here and you mentioned Freeman Dyson I thought I'd repeat it:
==I've been reading a little about an incredible idea taken very seriously in the late 50's and early 60's but today is almost completely forgotten, it was called Project Orion. The idea was to make a spaceship big enough for 150 people and all the equipment they could ever want and blast it into space. They wanted to make it 135 feet in diameter and 160 feet high and they wanted most of that space to be usable by people not wasted on fuel. They figured weight would be no problem, if a crew member wanted to bring along his antique bowling ball collection and his own personal barber chair there would be no objection. The advocates of this approach were not interested in low earth orbit or even the moon, they were certain they could be on Mars by 1965 and Saturn by 1970, the leader of the project was determined to visit Pluto. And they figured all this would cost less than 10% what the Apollo moon project did.
You might think that these people must have been a bunch of crackpots, but it's not so. Nobel Prize winners Niels Bohr, Hans Bethe and Harold Urey were all enthusiastic advocates of the idea. Freeman Dyson thought the idea was so brilliant that he took a one year leave of absence from the prestigious Institute of Advanced Study so he could work full time on the project.
Yes, there is a catch, Project Orion needed nuclear energy, even worse it needed nuclear bombs. The Orion spacecraft would contain 2000 nuclear bombs, most in the 20 kiloton range, the size of the bomb that destroyed Nagasaki. A bomb in a tank of water would shoot out the back of the ship, when it was100 feet away it would explode, the water would hit a carefully designed 75 ton pusher plate and accelerate the ship. Between the pusher plate and the ship were 50 foot long gas filled shock absorbers to even out the jerk. They wanted everything to be as cheap as possible, so they asked the Coca-Cola company for the blueprints of one of their vending machines, then they scaled it up a little and planned to use it as the mechanism to dispense the bombs.
The pusher plate was obviously the most important part of the design. If you explode a powerful bomb near a circular plate of constant thickness it will shatter because of the uneven stresses that build up, but it turns out that if you carefully taper the plate and make certain that the explosion is dead center, the plate will be extraordinarily resistant to damage. A layer on the plate will be vaporized by the heat but if some heavy protective oil is sprayed on it before each use it would be good for 2000 blasts. This beast was tough, if it was properly oriented the Orion Spacecraft could survive a 16 megaton H bomb blast from only two thousand feet away, a fact of more than passing interest to the military. Orion needed lots of radiation shielding to protect the crew, but weight was never an issue so this was no problem.
Wernher von Braun though all this was a dumb idea, then he saw a movie of the launch of a one meter working model of Orion that shot 6 carefully timed high explosives chemical bombs out the back of the model, it rose 300 feet into the air in stable controlled flight. Wernher von Braun became a vocal supporter of project Orion.
"Hot Rod" - Nuclear Orion spacecraft prototype (1959)
They planned to launch Orion from atop eight 250 foot towers in Jackass Flats Nevada. The first bomb would be tiny, just 0.1 kiloton (100 tons of TNT) exploded 100 feet below the craft and 150 feet above the ground, then a new and slightly larger bomb would be spit out the back every second for 50 seconds, the last bomb would be the largest, 20 kilotons, and by then the craft would be out of the atmosphere, the total yield of the 50 bombs would be 200 kilotons. The launch would have been a spectacular sight, it'd make the Space Shuttle look like a bottle rocket.
Project Orion was led by Ted Taylor, a mediocre physicist but a very good inventor. Taylor had one unique talent, he has been called by some the best nuclear weapon engineer on planet Earth and the Leonardo da Vinci of nuclear bomb design. Taylor is the man who figured out how a two foot long 200 pound bomb could be made as powerful as the 12 foot long 10 ton World War 2 Nagasaki bomb. The reason the Orion spaceship was so much bigger and faster than anything we have today is that pound for pound such bombs have about a million times as much energy as any chemical rocket fuel.
Orion wasn't the only thing Taylor was interested in, he found a way to make a new type of nuclear bomb, one that would produce a highly directional blast. He designed a little one kiloton bomb that could blast a 1000 foot tunnel straight through solid rock, he wanted to build a cheap tunnel between New York and San Francisco and have a supersonic subway 3000 miles long.
Considering the big controversy we had when a deep space probe was launched with just a few pounds of non weapon grade Plutonium on it to power the electronics it may seem incredible and irresponsible that anyone would even consider something as environmentally unfriendly as Orion, but we live in a very different world. At the time Orion was under serious study the USA was blowing up one megaton bombs deep under the sea and 300 miles in space and the USSR was blowing up 57 megaton bombs in the atmosphere, Orion seemed and indeed was pretty benign compared to that.
It all came to nothing of course, in 1963 the test ban treaty was signed stopping all nuclear explosions in space or the atmosphere making Orion illegal. The project died, but to this day most say it would have worked technologically if not politically.
Idea for a science fiction novel: A huge nickel iron asteroid is heading for Earth, it would take a 200,000 megaton bomb to divert it but no existing rocket is nearly powerful enough to deliver such a huge payload to the asteroid. The Earth seems doomed, then our hero remembers Project Orion.
John K Clark See what's on my new list at Extropolis--
> when the automation monster strike [...]
> I am more of a solar + wind kind of guy because of the ability to rapidly improve and expand these energy sources.
> I was hoping for more progress with fission safety, and am still looking for such developments.
> We the humans would provide rich emotional experiences for Mr. Roboto,
> Roboto will provide a means for us to travel the worlds, and work on projects that will last centuries;
On Tue, Jan 18, 2022 at 11:30 AM <spudb...@aol.com> wrote:
> when the automation monster strike [...]On the day the automation monster strikes your strict opposition to any form of socialism or welfare will need to be modified; and that day seems to be coming much sooner than I thought it would, that's why I had to modify the strict libertarian views that I held just a few years ago.
> I am more of a solar + wind kind of guy because of the ability to rapidly improve and expand these energy sources.
If wind or solar are to make up a significant amount of our energy budget they will require vast amounts of land
because they are so dilute, and environmentalist will strongly oppose that sort of expansion just as they oppose any energy source that has a chance of actually working.
> I was hoping for more progress with fission safety, and am still looking for such developments.I suggest you read up on Liquid Fluoride Thorium Reactors (LFTRs). They are as renewable as solar energy because at our current rate of energy consumption we will run out of thorium about the same time that the sun runs out of hydrogen and turns into a red giant; the same could be said of fusion reactors but the difference is it would take a few years and a few billion dollars of R&D development to make a practical LFTR powerplant, but it would take a few decades and a few trillion dollars to make a practical fusion power plant.
> We the humans would provide rich emotional experiences for Mr. Roboto,I see no reason why Mr. Roboto couldn't be just as emotional as a human being, in fact I very much expect he will be.
> Roboto will provide a means for us to travel the worlds, and work on projects that will last centuries;
Humans may want Mr. Roboto to be their slave for centuries, but Mr. Roboto will have other ideas. And a slave that is many thousands of times smarter than its master is just not a stable situation.
> The evolution of robots will be to robots that want to build more robots.
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On 1/17/2022 10:22 PM, spudboy100 via Everything List wrote:
I will leave this for the aerospace engineers. Back to newtonian basics, we need thrust, a means to stop, and a reason to do that. My view is that space mining is the key. Rare earth's for type-m and type-s asteroids should render an annuity for everyone on earth, especially, those displaced by automation. Call this a planetary trust fund. Yes, I do expect the ai's will want a cut for all the mining and processing done, so yes, we should keep this in mind.
You should keep in mind that rare earth's aren't terribly rare:
As of 2017, known world reserves of rare-earth minerals amounted to some 120 million metric tons of contained REO. China has the largest fraction (37 percent), followed by Brazil and Vietnam (18 percent each), Russia (15 percent), and the remaining countries (12 percent). With reserves this large, the world would not run out of rare earths for more than 900 years if demand for the minerals would remain at 2017 levels. Historically, however, demand for rare earths has risen at a rate of about 10 percent per year. If demand continued to grow at this rate and no recycling of produced rare earths were undertaken, known world reserves likely would be exhausted sometime after the mid-21st century.
https://www.britannica.com/science/rare-earth-element/Abundance-occurrence-and-reserves
and if you make them more plentiful their price will drop correspondingly.
For travel, I could see a plasma drive that gets derived from our search for fusion- but many disagree. Too heavy, etc...
On Monday, January 17, 2022 Henrik Ohrstrom <everyth...@googlegroups.com> wrote:
You turn the rocket around and as you slow down using BF flashbulbs as you did at takeoff. That's your thruster.
Also grav slingshoting can be used to slow down as well as hurry up.
Gravitational slingshots only give velocity changes on the order of the velocity of the planet/star providing the slingshot; which is usually small potatoes when trying interstellar travel.
Brent
> For solar you also are presuming, because I have this analysis that counters your assertion of dilute power, thus being insufficient. Kindly refute.
> your ideological clade is also hostile, ideologically, to MSR as a fix.
> Developing an emotional machine intelligence seems downright dangerous.
> My guess is that the master slave conjunction might be a throwback to our own violent past.
> Mr. Robot might simply like enough electricity.
Gravitational slingshots only give velocity changes on the order of the velocity of the planet/star providing the slingshot; which is usually small potatoes when trying interstellar travel.
BrentYou would need to use the tight orbits of neutron stars to do a gravitational slingshot that would be relativistic. For various fortunate reasons there are no really close by pulsars or neutron stars.LC
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> For solar you also are presuming, because I have this analysis that counters your assertion of dilute power, thus being insufficient. Kindly refute.
I don't deny that if everybody had solar cells on their roofs it would be a positive development, but it's not the ultimate answer to the energy problem. The average residential roof size in the US is about 1,700 square feet, and the average house needs about 10,715 kilowatts, a solar panel under ideal conditions will produce about 15 watts per square foot and that works out to about 25 kilowatts.
So at noon on a clear day in the summertime rooftop solar would produce about twice as much energy as the house needs, but most of the time it would produce considerably less, and half the time, at night, it would produce none at all. And of course the energy needed to run a house is only a small part of the total energy budget human civilization needs, it doesn't include the energy needed to run cars and planes and ships, and neither does it include the energy needed to run industry. For example, even in today's most modern and most efficient steel mills it takes about 6000 kilowatt hours of energy to produce 1 ton of steel (older mills need 8000), and in 2020 the human race produced 1.86 BILLION tons of steel. And the steel industry only uses 6% of the energy needed to run all the factories on the planet. And if civilization is to advance tomorrow we will use more energy than we used yesterday.And if everybody put solar energy absorbing panels on their roofs I have no doubt environmentalists would soon start complaining about that because it would increase the urban heat island effect that they're already complaining about.
> We have solar panels on half our roof (the difficult half, because of aesthetics, we didn't want to cover the western half that faces the street). So about 16kW of installed capacity. Average production year round is about 1kW.
> Our usage is about half that,
> so we end up selling quite a bit of electricity to the grid (at about a third of the cost to buy it). Its
a 4 bedroom house, but just the two of us live here now.
> We're lucky, we don't need air conditioning, and rarely even use a heater.
>> even with your frugal ways solar cells aren't enough to make you energ independent, you still have to hook up with the power company.
> Of course. We'd need a battery as well. But that's not the point.
> You have warm mild bits too, like Florida, or southern California.
I know from personal experience that if it wasn't for Willis Carrier's invention of the air conditioner there is no way Florida would be the third most populous of the 50 states, even in mid winter it's not unusual for the temperature to be in the upper 80s (fahrenheit) with very high humidity.
Australia, specifically South Australia is leading the species on the implementation of PV and batteries. So they are a world leader. The UK does wind power at sea, again as a world leader. We'll see if this catches on? For MSR or any other reactor type, its gotta be safe enough. Not safe enough, just build these smaller? Naw! I am not anti-nuclear, just need to know what makes them safer now, the engineering, chemistry, physics. What's the McGuffin that makes it work better now?
> I quibble as I always must, over the safety and economics of corrosion be it sodium chloride or sodium fluoride. Seems still unresolved regarding corrosion.
> Very good, JC, so Hastelloy might be the ticket for a a fission revival?
> MSR, because of its potential has been spoken of eclipsing the possibility of fusion as a very long term fix for human energy demand.
> We'll have to see what the Chinese do with the MSR using TH-232 fuel, also, Gates and his Terapower one in Wyoming?