tj, designing CPUs to be highly redundant and therefore durable is the best solution "scientifically", but you are right that's its not necessarily the most pragmatic solution. The reality is that providing core systems are sufficiently redundant to ensure catastrophic failure is unlikely, then the best solution would be to carry a bunch of spare components which are well protected. These days the elecronics part of any machine is usually the smallest and lightest.If this idea is combined with a modualr approach to the overall design of the space craft then the risk of irreparable damage due to solar storms and random cosmic rays would be small.
timmins, I think you have a good point, the total number of lunar astronauts is small and they were certainly not a representative sample of homosapiens of the 1960s and 70s.
Yeah guys, the my very cursory and rather unscientific investigion was to see if a bunch of them had died within say 10-20 years of the Apollo missions, due to cancer and such, which could be indicative of radiation damaged cells going cancerous, etc.. I didn't see any such trend, and if someone makes it into their 80's (several Apollo astronauts have), yeah every day is a blessing at that point. I was looking for a dramatic shift in life expectancy (to the lower range) in their group vs. the whole, and I didn't see one.
That's not to say that there weren't any issues, just that we didn't see say Chernobyl-level increases in death rates, cancer rates, leukemia, etc..
It looks like 24 astronauts orbitted the moon, and 12 of those got to walk on it. 15 of those men (6 of those being moonwalkers) are still alive today, and are in their 80's...
The fact that over half are still alive in their 80's is probably a good indicator that their radiation exposure rates weren't lethal in the short or mid term. The longest Apollo moon mission was a little over 12 1/2 days, from launch to return that being Apollo 17. 2 of the 3 Apollo 17 astronauts made it into their '80s, and one is still alive today.
Edited for better accuracy. John Young flew two missions, and got to walk on the moon on one of those two missions.
I did look up a few of the Apollo Astronauts on Wiki recenly, to see if a bunch of them had been dying prematurely. Most of them have had very long lives, so apparently the short amount of time they spent around/on the moon resulted in doses of solar radiaton that were within acceptable levels.
The Apollo missions were pretty much a roll of the dice. The CM was shielded enough to protect (at least to some extent) against normal radiation levels, but if there had been a major solar event while the astronauts were half-way to the Moon — or worse, sitting on the surface — it would have been A Very Bad Day. There would have been no warning of this, the SOHO satellite which detects hot stuff coming our way wasn't launched until the 1990s.
As for living on the moon for longer periods, well that may be a different story, and I'm sure the experts have been looking at that.
They have indeed. One of the favoured ideas in many of the studies that have been done over the years is building (or launching from Earth) habitats that can be buried under a layer of lunar soil.
Another idea that is exciting, for moon bases, is sending robots that can dig out bases and essentially fabricate blocks out of lunar soil to build them.
3d printing on various scales offers some great ways to cut down on the problem of, well, shipping.
Another idea that is exciting, for moon bases, is sending robots that can dig out bases and essentially fabricate blocks out of lunar soil to build them.
3d printing on various scales offers some great ways to cut down on the problem of, well, shipping.
Maybe I'm easily amused these days, but it strikes me funny that the G2 space suit is called 'retro' when in fact NASA's mini-spaceships are a relic of the past. Besides costing much less and being far less restrictive, a flexible counter-pressure suit might actually offer greater protection against solar and cosmic rays due to a reduction in secondary (bremsstrahlüng) radiation. I think I spelled that right...
Yes, the Space Base is a potentially useful set of elements, and a screamin' bargain at the price. I snagged that when I first laid eyes on it
I think scrubbing the lettering out of the space base is annoyingly difficult (i.e.: modify all the diffuse maps), that's my only complaint.
But it was pretty easy to convert to Iray; I think I only needed to change the luminosity for lights since conversion managed to turn ambient to emissive
@ Blind Owl, you are right in pointing out that a simple metal sheet is not always the smartest radiation protection. Heavy elements, such as lead, are good at absorbing radiation of various types but they are also particularly prone to producing Bremsstrahlüng radiation, which is, as you say, secondary (lower energy) radiation caused by the absorption of the primary radiation. All high energy radiation can cause Bremsstrahlüng, so therefore so can Bremsstrahlüng radiation cause further Bremsstrahlüng radiation. So wearing lead underpants is not always the smart solution :) Lighter elements may have less stopping power but produce much less if any Bremsstrahlüng radiation, so boron infused underpants might be better, depending on the type of radiation, eg. partical or electromagnetic (...and no I don't really want to get into a discussion of whether matter is just a specific form of energy!). So called Z-shielding consistes of a series of layers of different materials designed to give acceptable stopping power whilst reducing Bremsstrahlüng radiation. So indeed I can believe that a cleverly designed and made suit could offer significant protection against solar wind (particle radiation). In the end, water with boric acid is a pretty good option for stopping high energy radiation including cosmic rays, but you need quite a bit of it.
So, a clever suit to stop "low level" background radiation combined with a water/ice shelter or bolt-hole to run to during a period of high solar activity might be a good design for a long voyage. As for extra-solar cosmic radiation, well that's random so you would need a permanent shield. Interestingly one of the most energetic cosmic radiation events ever recorded was a single nucleus with an estimated energy equivalent of a cricket ball travelling at 60 miles per hour... in a single atom! Fortunately these are extremely rare, and no suit will offer protection. Maybe it would pass through you just killing a few cells on the way.
@ Isaac Newton: I'm guessing you've read Robert Zubrin's How to Live on Mars, which makes many of the same points. To anyone who hasn't, I recommend it highly (though I have to admit his heavy attempts at humor soon got tiresome for me). In his book Entering Space, (another book I highly recommend) Zubrin also makes some points about the use of superconductors to slow interstellar spacecraft without the need to spend half the fuel load to do it. Sort of like Bussard's ramjet--which wouldn't work anyway--only in reverse.
This would be huge for the (presumably) distant future if true high-temp superconductors are ever developed, which does seem likely. For the interim future, the magnetic fields such superconductors generated could be used to deflect charged particles in space, or on planets or planetoids without significant atmospheres. This seems a plausible near-term way of having any kind of space suit our hearts desire, as long as it holds air and provides enough pressure to hold the wearer and his/her parts together. Of course the problem of uncharged massive particles and electromagnetic radiation--UV to X to gamma and beyond--would still have to be addressed, but for sci-fi purposes I'd be prepared to assume half the battle won.
@ Isaac Newton: I'm guessing you've read Robert Zubrin's How to Live on Mars, which makes many of the same points. To anyone who hasn't, I recommend it highly (though I have to admit his heavy attempts at humor soon got tiresome for me). In his book Entering Space, (another book I highly recommend) Zubrin also makes some points about the use of superconductors to slow interstellar spacecraft without the need to spend half the fuel load to do it. Sort of like Bussard's ramjet--which wouldn't work anyway--only in reverse.
This would be huge for the (presumably) distant future if true high-temp superconductors are ever developed, which does seem likely. For the interim future, the magnetic fields such superconductors generated could be used to deflect charged particles in space, or on planets or planetoids without significant atmospheres. This seems a plausible near-term way of having any kind of space suit our hearts desire, as long as it holds air and provides enough pressure to hold the wearer and his/her parts together. Of course the problem of uncharged massive particles and electromagnetic radiation--UV to X to gamma and beyond--would still have to be addressed, but for sci-fi purposes I'd be prepared to assume half the battle won.
You just gave me a very silly idea for an earth orbit based interplanetary launch system. Essentailly a series of electro-magnetic rings configured in an array several miles long. It'd accelerate the spacecraft, mass driver style, with the rings repositioning/re-spacing themselves between shots using maneuvering thrusters (my guess is that they'd 'recoil' a bit as they 'grabbed' the object accelerating through them.. It'd have to be a longer array because you need to keep the accelleration down to human tolerable levels, say 1-3+ g's. Your suggested method of deceleration would come into play later, as the craft approached it's destination.
A similar system could be deployed at the destination to accomodate deceleration as well, once a colony was established... This could theoretically act as a 'reverse mass-driver' or 'mass decelerator, by lining the rings up along the ship's trajectory.
The advantage of such a system (if it could be made to work) is that the spacecraft would need less fuel for it's trip, as a good chuck of the energy/velocity required would be provided via the mass driver system in earth orbit.
Have you read The Millennial Project by Marshall T. Savage? That guy has to be the weirdest combination of well-read , idealistic, scientifically literate visionary and infuriating (at least to my skeptical taste) new-age flake I've ever run across. Among many other things (Lord, how many other things), he proposes to build a vacuum-sealed underground mass driver near the Equator, with Mt. Kilimanjaro his preferred location (for what appear to be sound engineering reasons), and with final boost to orbit provided by Earthbound lasers that can be tuned to penetrate our atmosphere to the extent needed under highly variable weather conditions. Whew! I think the term 'idiot savant' was coined with him in mind. If you can stand his 'Manifest destiny' drivel, you'll find the book an entertaining, informative, and often thought-provoking sleighride. Whatever else Savage lacks, it isn't ideas.
And if you're still fishing for wild ideas, you might also want to check out Gerard K. O'Neill's proposal for huge aerostat launch platforms big enough for spacecraft to land on and take off from, floating high above most of Earth's atmosphere.. In other words a not-quite space elevator that doesn't require limitless supplies of unobtainium. O'Neill was another visionary idealist, but he was also a physicist by trade. I think he had his bolts on a little tighter than Savage does. Many of his ideas are hopelessly impractial though technically within present or near-future human capabilities, but in any case they are appealing. He was one of the first, and by far the most persuasive, advocate of L5-type colonies. His The High Frontier and 2081: a Hopeful View of the Human Future are on my bookshelf, and both are thoroughly dog-eared. Some suggestions, for whatever they may be worth.
[ usual edit/afterthought: By 'several miles' you must mean several hundred or even several thousands of miles, if protoplasmic organisms were to have any hope of surviving. ]
Blind Owl, I haven't read any of Zubrin's work, though maybe I should; it sounds fun ;)
I love the concept of using room temperature super conductors to create magnetic shields against particle radiation. Presumably they would draw more current the more radiation they were deflecting.
Not only fun, but extremely informative: Zubrin is a rocket scientist (for real) and engineer who used to work for Martin Marietta and he knows his stuff, although he is something of a space enthusiast...as who among us isn't? Besides possessing what I assume is a solid grasp of the technical problems involved in space exploration, he's well acquainted with the NASA mindset and the parasitical nature of its relationships with its contractors. Some of it makes for pretty grim reading, about like turning over a rock and seeing what's under it.
If you decide to investigate further, I'd suggest you start with The Case for Mars. I've almost worn out my copy of that one. Fair warning: if you read one of his non-fiction books, you'll want 'em all.
re: superconductors, whether high or low-temp, I must confess that my knowledge of the subject is inadequate to comment. The very concept of a current that can flow endlessly, without further input and without any electrical resistance at all, is passing strange to me.
Crap, I can't resist a Zubrin teaser: in one of his books, he proposes a high-efficiency rocket motor powered by uranium salts dissolved in water. Except for the problem of getting approvals, the idea might actually work.
tkdrobert, now that's the kind of vehicle people would pay to see trundling around Mars... sexy!
BlindOwl, it's proably totally rediculous, given the size of space, but my first reaction to a rocket motor that spews uranium all over the place is, Nooooooo! I just wish the boffins at Cern would get their collective fingers out and get on with working out how to make a working hydrogen fusion reactor! Yes, I know it's a tough nut to crack, but hurry up guys, the world needs cheap, clean energy... fast!
Flourine makes great rocket fuel that's also absurdly toxic. There's one form that's super energetic but was described as 'if there's a leak you will have to remove the pilot with a wet vac'
BlindOwl, it's proably totally rediculous, given the size of space, but my first reaction to a rocket motor that spews uranium all over the place is, Nooooooo! I just wish the boffins at Cern would get their collective fingers out and get on with working out how to make a working hydrogen fusion reactor! Yes, I know it's a tough nut to crack, but hurry up guys, the world needs cheap, clean energy... fast!
Presumably a large proportion of those uranium atoms would be 'spent' by the time they were spewed out as rocket exhaust, but yes, it would be a very hard sell. Even if the anti-nuke lobby didn't get involved--not bloody likely!---can you imagine the environmental impact statements it would take to get permits to even test such engines, never mind fly them?
Still, Zubrin's proposed NSWR (nuclear salt-water rocket) is a clever idea that has many potential advantages over e.g. exploding micro A-bombs (as depicted in Niven & Pournelle's Footfall, if memory serves) behind a spaceship. Now that's one crack-brained idea! Not only do you have to build A-bombs by the hundreds or perhaps thousands (A-bombs which could be used for less benign purposes), there may be a possibility that some of the resulting debris would be significantly larger than molecule-sized, with potentially disastrous consequences for anything that ran into it. With an NSWR, all the exhaust would be in the form of molecules or single atoms.
An NSWR would use some optimized variation of the standard bell-type rocket nozzle, making it far more efficient and probably much lighter than a ship with a big fat 'pusher' plate and super-duty shock absorbers to take the tremendous (and tremendously variable) thrust loads. And, unlike the pusher-plate concept, an NSWR could be throttled by simply varying the liquid flow. With the specific impulses available from a continuous 'prompt critical' fission reaction, Earth-to-Mars travel times might be measured in weeks rather than half-years.
Yeah, fusion *sighs*. Back in '89 I happened to be on vacation in Mexico, driving the length of the Baja peninsula, when those poor feebs in Utah announced that they had achieved 'cold' fusion. Limited though my understanding of physics was and is, I was suspicious. Couldn't be that easy, had to be a mistake. I didn't know that the perpetrators (or self-deluded victims, take your pick) were chemists, not physicists. Just the same, I remember looking out at the Sea of Cortez and thinking "Wow, this could change everything. Everything."
I wouldn't count on CERN to develop a working fusion reactor because that's not their primary mandate. Seems to me it would take well-funded (extremely well-funded) institutions with 'achieve practical fusion reactors or else' written into their charters as their sole purpose.
FWEIW, as always... (new acronym I just coined, meaning for whatever it's worth).
Flourine makes great rocket fuel that's also absurdly toxic. There's one form that's super energetic but was described as 'if there's a leak you will have to remove the pilot with a wet vac'
Sort of like the "100% pure hydrogen peroxide" idea, huh? One little contaminating speck and...
Sort of like the "100% pure hydrogen peroxide" idea, huh? One little contaminating speck and...
100%...? Ouch. The peroxide used in WW2 German rockets like the Me-163 was bad enough, and it was only(!) 80% — any leaks tended to dissolve anything organic, such as the pilot's seat stuffing, the pilot's clothes, the pilot... that stuff is nasty.
Sort of like the "100% pure hydrogen peroxide" idea, huh? One little contaminating speck and...
100%...? Ouch. The peroxide used in WW2 German rockets like the Me-163 was bad enough, and it was only(!) 80% — any leaks tended to dissolve anything organic, such as the pilot's seat stuffing, the pilot's clothes, the pilot... that stuff is nasty.
True confession, SpottedKitty: I was rehashing percentages from memory. At any rate, highly concentrated hydrogen peroxide will explode if it comes into contact with even minute impurities, which can act as a catalyst. Compared to that risk, its corrosive properties are a relatively minor hazard, though far from trivial.
It's much more involved than your typical Tokomak, and despite the fact that the design concept has been around for decades, it has required huge amounts of computing horsepower/time to get the design to this point. The design involves some 'misshaped' magnets to achieve the field dynamics that they are going for. One of the comments below the article notes that the magnet geometries really fit/invoke the design of some of the 'asymmetrical' alien ship environments we've seen here and there in sci fi.
It's a good read, and delves a bit into the plasma physics involved. Looks like something that should be quite interesting to a few of you following this thread!
lol.. my first reaction to the Stellarator..."It's a cyberpunk fusion reactor!" Put a couple of cogs and dials in to the mix and it could be a Steampunk fusion reactor!
I think I need to make the film effect a little more subtle, to be honest. Glancing over shots of moon walks, the NASA images are actually pretty awesome/clear:
I think I need to make the film effect a little more subtle, to be honest. Glancing over shots of moon walks, the NASA images are actually pretty awesome/clear:
Yeah, most of the lunar pics I remember have high levels of contrast, with very crisp and dark shadows, so I think you are on the right track r.e. doing some tweaks, and emphasizing the shadows more. I'm guessing it's the high contrast look that makes the NASA lunar pics so compelling.
The Earth could be used a weak secondary source for light, and might look really cool in the background if you can arrange it!
That may just be the type of camera that the astronauts used though, but since there aren't any atmospheric molecules (well trace amounts maybe) to distort the light as it travels from the object to the camera, it makes sense why the images are so crisp.
That's a very nice looking scene you've put together there!
Several pages back, I posted some images of the kind of content I'd like to see more of. I didn't include any by an artist named Chesley Bonestell (pron: bon' estell, as in 'good star') because they seem hopelessly dated now; but in the days before any rocket had even reached orbit--never mind returned pictures--Bonestell's paintings were pure magic for space-starved sci-fi freaks.
Several pages back, I posted some images of the kind of content I'd like to see more of. I didn't include any by an artist named Chesley Bonestell (pron: bon' estell, as in 'good star') because they seem hopelessly dated now; but in the days before any rocket had even reached orbit--never mind returned pictures--Bonestell's paintings were pure magic for space-starved sci-fi freaks.
Flourine makes great rocket fuel that's also absurdly toxic. There's one form that's super energetic but was described as 'if there's a leak you will have to remove the pilot with a wet vac'
I don't think it's the same thing you're referring to, but they experimented with chlorine trifluoride as an oxidizer. From a theoretical energy production standpoint, it was perfect, but it had some practical difficulties. Here's one rocket scientist's description (note: hypergolic = ignites on contact):
"It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes."
Comments
tj, designing CPUs to be highly redundant and therefore durable is the best solution "scientifically", but you are right that's its not necessarily the most pragmatic solution. The reality is that providing core systems are sufficiently redundant to ensure catastrophic failure is unlikely, then the best solution would be to carry a bunch of spare components which are well protected. These days the elecronics part of any machine is usually the smallest and lightest.If this idea is combined with a modualr approach to the overall design of the space craft then the risk of irreparable damage due to solar storms and random cosmic rays would be small.
timmins, I think you have a good point, the total number of lunar astronauts is small and they were certainly not a representative sample of homosapiens of the 1960s and 70s.
Yeah guys, the my very cursory and rather unscientific investigion was to see if a bunch of them had died within say 10-20 years of the Apollo missions, due to cancer and such, which could be indicative of radiation damaged cells going cancerous, etc.. I didn't see any such trend, and if someone makes it into their 80's (several Apollo astronauts have), yeah every day is a blessing at that point. I was looking for a dramatic shift in life expectancy (to the lower range) in their group vs. the whole, and I didn't see one.
That's not to say that there weren't any issues, just that we didn't see say Chernobyl-level increases in death rates, cancer rates, leukemia, etc..
It looks like 24 astronauts orbitted the moon, and 12 of those got to walk on it. 15 of those men (6 of those being moonwalkers) are still alive today, and are in their 80's...
The fact that over half are still alive in their 80's is probably a good indicator that their radiation exposure rates weren't lethal in the short or mid term. The longest Apollo moon mission was a little over 12 1/2 days, from launch to return that being Apollo 17. 2 of the 3 Apollo 17 astronauts made it into their '80s, and one is still alive today.
Edited for better accuracy. John Young flew two missions, and got to walk on the moon on one of those two missions.The Apollo missions were pretty much a roll of the dice. The CM was shielded enough to protect (at least to some extent) against normal radiation levels, but if there had been a major solar event while the astronauts were half-way to the Moon — or worse, sitting on the surface — it would have been A Very Bad Day. There would have been no warning of this, the SOHO satellite which detects hot stuff coming our way wasn't launched until the 1990s.
They have indeed. One of the favoured ideas in many of the studies that have been done over the years is building (or launching from Earth) habitats that can be buried under a layer of lunar soil.
Another idea that is exciting, for moon bases, is sending robots that can dig out bases and essentially fabricate blocks out of lunar soil to build them.
3d printing on various scales offers some great ways to cut down on the problem of, well, shipping.
Also, in my bid for more believable ...
( https://www.daz3d.com/space-base )
( https://www.daz3d.com/retro-space-suit-for-genesis-2-male-s )
Maybe I'm easily amused these days, but it strikes me funny that the G2 space suit is called 'retro' when in fact NASA's mini-spaceships are a relic of the past. Besides costing much less and being far less restrictive, a flexible counter-pressure suit might actually offer greater protection against solar and cosmic rays due to a reduction in secondary (bremsstrahlüng) radiation. I think I spelled that right...
Yes, the Space Base is a potentially useful set of elements, and a screamin' bargain at the price. I snagged that when I first laid eyes on it
I think scrubbing the lettering out of the space base is annoyingly difficult (i.e.: modify all the diffuse maps), that's my only complaint.
But it was pretty easy to convert to Iray; I think I only needed to change the luminosity for lights since conversion managed to turn ambient to emissive
@ Blind Owl, you are right in pointing out that a simple metal sheet is not always the smartest radiation protection. Heavy elements, such as lead, are good at absorbing radiation of various types but they are also particularly prone to producing Bremsstrahlüng radiation, which is, as you say, secondary (lower energy) radiation caused by the absorption of the primary radiation. All high energy radiation can cause Bremsstrahlüng, so therefore so can Bremsstrahlüng radiation cause further Bremsstrahlüng radiation. So wearing lead underpants is not always the smart solution :) Lighter elements may have less stopping power but produce much less if any Bremsstrahlüng radiation, so boron infused underpants might be better, depending on the type of radiation, eg. partical or electromagnetic (...and no I don't really want to get into a discussion of whether matter is just a specific form of energy!). So called Z-shielding consistes of a series of layers of different materials designed to give acceptable stopping power whilst reducing Bremsstrahlüng radiation. So indeed I can believe that a cleverly designed and made suit could offer significant protection against solar wind (particle radiation). In the end, water with boric acid is a pretty good option for stopping high energy radiation including cosmic rays, but you need quite a bit of it.
So, a clever suit to stop "low level" background radiation combined with a water/ice shelter or bolt-hole to run to during a period of high solar activity might be a good design for a long voyage. As for extra-solar cosmic radiation, well that's random so you would need a permanent shield. Interestingly one of the most energetic cosmic radiation events ever recorded was a single nucleus with an estimated energy equivalent of a cricket ball travelling at 60 miles per hour... in a single atom! Fortunately these are extremely rare, and no suit will offer protection. Maybe it would pass through you just killing a few cells on the way.
@ Isaac Newton: I'm guessing you've read Robert Zubrin's How to Live on Mars, which makes many of the same points. To anyone who hasn't, I recommend it highly (though I have to admit his heavy attempts at humor soon got tiresome for me). In his book Entering Space, (another book I highly recommend) Zubrin also makes some points about the use of superconductors to slow interstellar spacecraft without the need to spend half the fuel load to do it. Sort of like Bussard's ramjet--which wouldn't work anyway--only in reverse.
This would be huge for the (presumably) distant future if true high-temp superconductors are ever developed, which does seem likely. For the interim future, the magnetic fields such superconductors generated could be used to deflect charged particles in space, or on planets or planetoids without significant atmospheres. This seems a plausible near-term way of having any kind of space suit our hearts desire, as long as it holds air and provides enough pressure to hold the wearer and his/her parts together. Of course the problem of uncharged massive particles and electromagnetic radiation--UV to X to gamma and beyond--would still have to be addressed, but for sci-fi purposes I'd be prepared to assume half the battle won.
You just gave me a very silly idea for an earth orbit based interplanetary launch system. Essentailly a series of electro-magnetic rings configured in an array several miles long. It'd accelerate the spacecraft, mass driver style, with the rings repositioning/re-spacing themselves between shots using maneuvering thrusters (my guess is that they'd 'recoil' a bit as they 'grabbed' the object accelerating through them.. It'd have to be a longer array because you need to keep the accelleration down to human tolerable levels, say 1-3+ g's. Your suggested method of deceleration would come into play later, as the craft approached it's destination.
A similar system could be deployed at the destination to accomodate deceleration as well, once a colony was established... This could theoretically act as a 'reverse mass-driver' or 'mass decelerator, by lining the rings up along the ship's trajectory.
The advantage of such a system (if it could be made to work) is that the spacecraft would need less fuel for it's trip, as a good chuck of the energy/velocity required would be provided via the mass driver system in earth orbit.
It sounds cool in my head anyways!
Have you read The Millennial Project by Marshall T. Savage? That guy has to be the weirdest combination of well-read , idealistic, scientifically literate visionary and infuriating (at least to my skeptical taste) new-age flake I've ever run across. Among many other things (Lord, how many other things), he proposes to build a vacuum-sealed underground mass driver near the Equator, with Mt. Kilimanjaro his preferred location (for what appear to be sound engineering reasons), and with final boost to orbit provided by Earthbound lasers that can be tuned to penetrate our atmosphere to the extent needed under highly variable weather conditions. Whew! I think the term 'idiot savant' was coined with him in mind. If you can stand his 'Manifest destiny' drivel, you'll find the book an entertaining, informative, and often thought-provoking sleighride. Whatever else Savage lacks, it isn't ideas.
And if you're still fishing for wild ideas, you might also want to check out Gerard K. O'Neill's proposal for huge aerostat launch platforms big enough for spacecraft to land on and take off from, floating high above most of Earth's atmosphere.. In other words a not-quite space elevator that doesn't require limitless supplies of unobtainium. O'Neill was another visionary idealist, but he was also a physicist by trade. I think he had his bolts on a little tighter than Savage does. Many of his ideas are hopelessly impractial though technically within present or near-future human capabilities, but in any case they are appealing. He was one of the first, and by far the most persuasive, advocate of L5-type colonies. His The High Frontier and 2081: a Hopeful View of the Human Future are on my bookshelf, and both are thoroughly dog-eared. Some suggestions, for whatever they may be worth.
[ usual edit/afterthought: By 'several miles' you must mean several hundred or even several thousands of miles, if protoplasmic organisms were to have any hope of surviving. ]
Blind Owl, I haven't read any of Zubrin's work, though maybe I should; it sounds fun ;)
I love the concept of using room temperature super conductors to create magnetic shields against particle radiation. Presumably they would draw more current the more radiation they were deflecting.
Not only fun, but extremely informative: Zubrin is a rocket scientist (for real) and engineer who used to work for Martin Marietta and he knows his stuff, although he is something of a space enthusiast...as who among us isn't? Besides possessing what I assume is a solid grasp of the technical problems involved in space exploration, he's well acquainted with the NASA mindset and the parasitical nature of its relationships with its contractors. Some of it makes for pretty grim reading, about like turning over a rock and seeing what's under it.
If you decide to investigate further, I'd suggest you start with The Case for Mars. I've almost worn out my copy of that one. Fair warning: if you read one of his non-fiction books, you'll want 'em all.
re: superconductors, whether high or low-temp, I must confess that my knowledge of the subject is inadequate to comment. The very concept of a current that can flow endlessly, without further input and without any electrical resistance at all, is passing strange to me.
Crap, I can't resist a Zubrin teaser: in one of his books, he proposes a high-efficiency rocket motor powered by uranium salts dissolved in water. Except for the problem of getting approvals, the idea might actually work.
NASA Mars concept vehicle
https://www.digitaltrends.com/cars/nasa-mars-rover-concept/#/2
tkdrobert, now that's the kind of vehicle people would pay to see trundling around Mars... sexy!
BlindOwl, it's proably totally rediculous, given the size of space, but my first reaction to a rocket motor that spews uranium all over the place is, Nooooooo! I just wish the boffins at Cern would get their collective fingers out and get on with working out how to make a working hydrogen fusion reactor! Yes, I know it's a tough nut to crack, but hurry up guys, the world needs cheap, clean energy... fast!
Flourine makes great rocket fuel that's also absurdly toxic. There's one form that's super energetic but was described as 'if there's a leak you will have to remove the pilot with a wet vac'
Presumably a large proportion of those uranium atoms would be 'spent' by the time they were spewed out as rocket exhaust, but yes, it would be a very hard sell. Even if the anti-nuke lobby didn't get involved--not bloody likely!---can you imagine the environmental impact statements it would take to get permits to even test such engines, never mind fly them?
Still, Zubrin's proposed NSWR (nuclear salt-water rocket) is a clever idea that has many potential advantages over e.g. exploding micro A-bombs (as depicted in Niven & Pournelle's Footfall, if memory serves) behind a spaceship. Now that's one crack-brained idea! Not only do you have to build A-bombs by the hundreds or perhaps thousands (A-bombs which could be used for less benign purposes), there may be a possibility that some of the resulting debris would be significantly larger than molecule-sized, with potentially disastrous consequences for anything that ran into it. With an NSWR, all the exhaust would be in the form of molecules or single atoms.
An NSWR would use some optimized variation of the standard bell-type rocket nozzle, making it far more efficient and probably much lighter than a ship with a big fat 'pusher' plate and super-duty shock absorbers to take the tremendous (and tremendously variable) thrust loads. And, unlike the pusher-plate concept, an NSWR could be throttled by simply varying the liquid flow. With the specific impulses available from a continuous 'prompt critical' fission reaction, Earth-to-Mars travel times might be measured in weeks rather than half-years.
Yeah, fusion *sighs*. Back in '89 I happened to be on vacation in Mexico, driving the length of the Baja peninsula, when those poor feebs in Utah announced that they had achieved 'cold' fusion. Limited though my understanding of physics was and is, I was suspicious. Couldn't be that easy, had to be a mistake. I didn't know that the perpetrators (or self-deluded victims, take your pick) were chemists, not physicists. Just the same, I remember looking out at the Sea of Cortez and thinking "Wow, this could change everything. Everything."
I wouldn't count on CERN to develop a working fusion reactor because that's not their primary mandate. Seems to me it would take well-funded (extremely well-funded) institutions with 'achieve practical fusion reactors or else' written into their charters as their sole purpose.
FWEIW, as always... (new acronym I just coined, meaning for whatever it's worth).
Sort of like the "100% pure hydrogen peroxide" idea, huh? One little contaminating speck and...
100%...? Ouch. The peroxide used in WW2 German rockets like the Me-163 was bad enough, and it was only(!) 80% — any leaks tended to dissolve anything organic, such as the pilot's seat stuffing, the pilot's clothes, the pilot... that stuff is nasty.
True confession, SpottedKitty: I was rehashing percentages from memory. At any rate, highly concentrated hydrogen peroxide will explode if it comes into contact with even minute impurities, which can act as a catalyst. Compared to that risk, its corrosive properties are a relatively minor hazard, though far from trivial.
U.N "Urban pacification" vehicle
Here's a link to a story with some pretty pics of a fusion reactor design that's being worked on. Even the name is cool: The Stellarator.
https://arstechnica.com/science/2017/06/wibbly-wobbly-magnetic-fusion-stuff-the-return-of-the-stellarator/?comments=1
It's much more involved than your typical Tokomak, and despite the fact that the design concept has been around for decades, it has required huge amounts of computing horsepower/time to get the design to this point. The design involves some 'misshaped' magnets to achieve the field dynamics that they are going for. One of the comments below the article notes that the magnet geometries really fit/invoke the design of some of the 'asymmetrical' alien ship environments we've seen here and there in sci fi.
It's a good read, and delves a bit into the plasma physics involved. Looks like something that should be quite interesting to a few of you following this thread!
lol.. my first reaction to the Stellarator..."It's a cyberpunk fusion reactor!" Put a couple of cogs and dials in to the mix and it could be a Steampunk fusion reactor!
Another in my Yesterday's Tomorrows series, inspired by this thread. ;)
Series: http://willbear.deviantart.com/gallery/63227954/Yesterday-s-Tomorrows
New image: http://willbear.deviantart.com/art/Discovery-685651348
I think I need to make the film effect a little more subtle, to be honest. Glancing over shots of moon walks, the NASA images are actually pretty awesome/clear:
Actual lunar pic: https://upload.wikimedia.org/wikipedia/commons/4/4d/NASA_Apollo_17_Lunar_Roving_Vehicle.jpg
Yeah, most of the lunar pics I remember have high levels of contrast, with very crisp and dark shadows, so I think you are on the right track r.e. doing some tweaks, and emphasizing the shadows more. I'm guessing it's the high contrast look that makes the NASA lunar pics so compelling.
The Earth could be used a weak secondary source for light, and might look really cool in the background if you can arrange it!
That may just be the type of camera that the astronauts used though, but since there aren't any atmospheric molecules (well trace amounts maybe) to distort the light as it travels from the object to the camera, it makes sense why the images are so crisp.
That's a very nice looking scene you've put together there!
Several pages back, I posted some images of the kind of content I'd like to see more of. I didn't include any by an artist named Chesley Bonestell (pron: bon' estell, as in 'good star') because they seem hopelessly dated now; but in the days before any rocket had even reached orbit--never mind returned pictures--Bonestell's paintings were pure magic for space-starved sci-fi freaks.
Thanks for sharing!
I don't think it's the same thing you're referring to, but they experimented with chlorine trifluoride as an oxidizer. From a theoretical energy production standpoint, it was perfect, but it had some practical difficulties. Here's one rocket scientist's description (note: hypergolic = ignites on contact):
"It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes."
That's the kind of thing I mean. What a concept: space suits that would actually hold pressure...and not a weapon in sight!
Murgatroyd: That is precisely the quote I was thinking about, and I think I was conflating that with a different hideous fuel. Heh.
Tkdrobert: I LOVE that image