I would presume that while the field is quite robust, that the rate of alternation will be either absurdly fast, or very slow.
The first poses a risk of magstrips on credit cards of pedestrians and cyclists being wiped due to hysteresis. (The whole road would be one giant bulk eraser!) The latter makes this less likely, but is less efficient for AC power transfer over long distances of roadbed.
I suspect it will be a slow oscillation based charger, because a moving vehicle trying to get a stable wave for its charging circuit will have "short" moments of interaction with the individual coils in the roadbed as it drives over the top, causing significant headache. This in addition to being less likely to wipe magstrips on credit cards, and the like.
A slow oscillator will be more difficult to draw "large" quantities of electricity from, as the collector would need to be quite large and conspicuous.
Purchase a waterproof smartphone enclosure from a sporting goods store. Like say, these generic ones. insert the phone inside the protector, and seal it.
Step 2:)
At the local post office, purchase a normal cardboard shipping box. I understand walmart also carries these. Then, buy a can of expanding foam insulation. Squirt the expanding foam insulation into the cardboard box, then, while the foam is still expanding and workable, embed the enclosure inside the foam. (You want to be able to get the phone out of the enclosure later. Keep that in mind.)
Step 3:)
Load the cardboard "shock box" into a "pumpkin chucker" trebuchet. You may need to troll newspapers or craigs list to find someone who has one. (they tend to advertise having them, so all you need to do is look.) Set the angle nigh, then let it rip.
You should switch to a precision high intensity laser pulse rifle.
Some localized charring, and that's it! Granted, you need to wear the eye protection, and some NIMBYs complain about where the photons end up when you miss, but they are just whiners.
Filling the box channel with 2 part silicone rubber mix, then chasing it will produce a high precision casting negative of the channel, which can then be easily scanned. (and being rubber, easily extracted from the box channel)
Many software packages permit boolean remove operations, which would allow them to position the 3d scanned rubber impression onto a blank channel way, then boolean remove the negative to get the positive impressions again in the digital model.
Perhaps you should more closely look into what actually initiated subprime mortgage crisis.
The prevailing theory is that the repeal of the Glass-Steagall, and the implementation of the Commodity Futures Modernization Act of 2000.
Taken from this source, Then president clinton officially stated publicly that Glass-Steagall was no longer appropriate, and began measures to repeal it.
DENNIS KELLEHER, Better Markets, Inc.: In the old days, Wall Street and the finance industry financed things that got done, be they the railroads or the interstate system. All of that has to be financed. Thatâ(TM)s what finance is supposed to be about.
What has entirely changed is that theyâ(TM)re in the business of making money for themselves. If it happens that they can also finance something along the way, OK, but thatâ(TM)s really no longer part of the core business.
LARRY SUMMERS, Clinton Administration Treasury Secretary: Now it gives me great pleasure to introduce the President of the United States, William Jefferson Clinton.
NARRATOR: The changes were formalized in the late â90s, as the last of the Depression-era reforms were liftedâ"
Pres. BILL CLINTON: The Glass-Steagall law is no longer appropriateâ"
NARRATOR: â"and traditional commercial banks could merge with trading-oriented investment banks. Trading activity and bank profits rose quickly.
[www.pbs.org: The rise and fall of Glass-Steagall]
Later, After doing so, then president Href="http://en.wikipedia.org/wiki/Commodity_Futures_Modernization_Act_of_2000">Clinton signed the Commodity Futures Modernization Act of 2000 into law.
The prices of goods are rising, while the rate of wages remains constant, or slightly decrease with time. At the same time, improvements in production make fewer "high demand" (high pay) jobs available, as companies seek to offset the difference as profit.
Insisting on "Living wages or else!" is one possible solution to disinflation, yes, but is not the best one, since it does NOT resolve the issue of job scarcity while population slowly rises. You WILL eventually reach "Peak McDonalds" in terms of market demand, after which point, hiring more McDonalds people for (by then) 20$/hr is not sensible, and will cost the company money. Result: they just stop hiring, and unemployment rises.
This disinflation is a result of the globalist economy model. American pay is overinflated in comparison to the pay in China, or Bangladesh. Free trade to "bring up" those countries is working-- But at the cost of economically disadvantaging US and other 1st world economies.
As much as I really hate the dirty spectre of nationalism, trade tariffs are a tried and true method of keeping this disinflation from happening, while continuing foreign trade. The tariff for a particular good needs to reflect the difference in cost of production incurred by the foreign production, and the difference in inflation, of the two participating economies.
"Bring up the 2nd and 3rd world", VS "Keep the 1st world." You may pick *ONE*.
Agreed, for each nested brach, complexity increases at LEAST geometrically. (A branch always has at least 2 paths.) However, one may not NEED to know *all* branches.
Say for instance, the behavior you want to modify (we will assume you are a cracker making a memory poking drm defeat patch) is rigidly defined in where it gets called from (by this, I mean what code branches spawn the check). You don't really need to look at the other execution paths, just the ones that trigger the drm check, or better still, the check routine itself that gets called. Having execution jump all over the damned place instead of having it be nice and orderly in memory is basically the "spaghetti code" problem. Its just a bunch of jumps, with (*apparently) no rational scheme behind them.
The program itself needs to reliably know where to jump to, and what (*random) addresses to read and write to. Making a "complex" program be able to have a new "scatter" pattern on each fresh execution still requires a fixed entrypoint to decide which scatter pattern to use, and what data to poke after the scattering so that the code can still execute. This presents a point of attack. It also runs foul of the same complexity problem it attempts to present to the cracker; the more potential scatter patterns, the larger the scattering routine, the harder it is for it to poke all the right spots after the scattering to update all the jump instruction and data read/write addresses. Especially if it attemps to scatter its own data as well.
This is because such scattering has to be done intelligently, otherwise performance of execution will drop like a lead brick on jupiter. Say for instance, it does really dumb scattering, and scatters data for a 64bit unsigned integer as 8 addresses, each of 1 byte length, in a seemingly random jumble in the allocated memory image. Instead of 1 64bit linear read, or 2 sequential 32bit reads, it has to do 8 random 8 bit reads, AND process jump instructions injected by the scrambler, before it can actually perform the computation with that integer. The more complex the program scrambled, and the more complex the scrambler used, the greater the performance penalty will be. This places a hard upper bound on the hardness this approach can give the cracker.
Let's say we have a program that branches many times, as you describe above. The VM is controlled with a script. On the first pass, it looks for and records all instruction branches on the first program run along with the data compared against for each branch to execute, then reloads the saved state at initial program load, and begins systematically walking and triggering code.
On each pass, it spits out what the CPU did, with what inputs.
Since it is a given that new paths that weren't walked before will have yet more banches, the duty list of paths to walk needs to be amendable at runtime.
It may take a very long time to walk out all of the paths and completely map all code logic, but that then becomes something you turn on and then wander off to go eat a sandwich for. Most packages that will use this kind of obfuscation are going to be small, and the number of paths quite limited. However, very large monolithic executables are going to run into issues on how long it takes to fully map them. At that point, one just needs to ask themselves if they really need to fully map the obfuscated code, or if just certain well-used paths are good enough.
I was thinking more along the lines of "special processor instructions", that make use of quirks of real silicon. Given how intel and amd both have taken to cramming lots of extra devices onto the die, a small "inside the CPU" black box designed for this very application would do the trick just fine, and would likewise ensure its presence on modern rigs.
A virtual machine halting execution would be detected by the running software, because it wouldn't get the proper responses from said black box. You'd have to uncap the cpu, and watch with very specialist equipment.
I am thinking a small asynchronous secondary processor.
One way around this (for reverse engineering) would simply be to run it inside a VM with a built in stack trace debugger, like Bochs.
You can peek at the raw instructions percolating through the VM's emulated CPU that way. The application itself is then the decryption key, since the system has to be able to run the application.
PITA, but I don't see how this is anything more than just a "bigger" speedbump, at least as far as disassembly goes. Now, making said decryption require nasty bits of hardware to thwart using a VM, and clinging tightly to treacherous computing with a TPM and a hardware hypervisor on top of this? That's more dicey.
The question here is... why do this? Is preventing Cracker Jack from the warez scene from simply disabling your "authenticity checks" so horrifically important? That's the major application for this that I really see, besides making epically horrific malware. (Though if you ask me, they are both the same thing.)
Seriously, other than making personal computing become something from communist russia, what is the benefit of this?
This presumes the aliens have a lifespan similar to our own.
Just here on earth, compare:
Lifespan of a fruit fly: about 7 to 14 days. Time to travel across the US by highway, east to west: 7 to 14 days (depending on traffic and route taken)
What truckers do routinely as a vocation takes an entire lifetime for a fly.
Again, that's just here on earth.
If said aliens have 1000 year lifespans, then they could spend 300 years training for the mission, 300 years to get here from the nearest star, and 300 years to return there, and still have around 100 years to tell the rest of their civilization all about it. (We are assuming some non-trivial fraction of C during travel.)
The sun in a yellow dwarf variable star. Its solar output varies, and can be quite erratic. Its gravitational attraction would vary significantly less.
The issue is which set of problems you want to inherit from such an installation:
1) a constant stream of supply missions to keep the unstable L1 situated reflector on station using reaction mass propellant, spare parts for thruster ports and hose assemblies, and all the related logistics.
2) maintaing a tightrope teetering on an unstable orbital period that is sunward of L1, by dynamically altering the effective aperature of the reflector to dynamically match solar output in relation to solar gravity, and keeping a very watchful eye on the automated aperature control systems to avoid critical mission failure.
I think #2 would be "very challenging", but potentially significantly less expensive over the time frames required to affect substantive change on the venusian environment.
Again, without question or hesitation, the orbit *would* be unstable, and *would* require active, continual corrections.
The difference is that you can use light pressure as the reaction mass, and require much smaller logistical supply line resource allocation.
The platform would need to be able to deploy a significantly larger disc diameter than the "nominal" one, to overpower solar attraction when necessary, and also be able to substantially reduce its disc diameter when necessary, to fall deeper into the solar gravitational well.
That's a problem that can be solved with clever engineering, and would provide an "operational orbit zone" within which it would be able to perform such corrections, but beyond which it would require reaction mass to correct the fault.
The former requires constant and continual use of reaction mass to stay on station.
There is a manmade plastic called "aramid", which is comprised of nitrogen, carbon, and hydrogen. It has no melting temperature, and has a thermal decomposition temperature of approxmately 500c. (Just a little under the mean surface temperature for venus.) It dissolves, but does not denaturate in strong acids.
Should an atmospheric sulfur cycle bacterium be engineered to make use of this substance for cell walls, their little dead bodies resulting from their "natural" lifecycle would fall into the lower atmosphere, be dissolved in the sulfuric acid cloud layer, and accumulate as complex hydrocarbon compounds suspended in the supercritical CO2 below said layer. Up there, they should mix quite homogenously with the absurdly thick atmosphere, and eventually accumulate enough to precipitate in the solution. By that time, a significant portion of the atmosphere would have been organically processed into heavy, long chain hydrocarbons, resulting in reduced pressures, and reduced surface mean temperatures. Mean surface tempurature only needs to drop about 10c for the plastic molecules to remain thermally stable at the surface, meaning oceans of thick plastic goop would begin to form on the surface as the plastic + anhydrous sulfuric acid rain out.
We could probably initiate this process right now using existing technology. However, much like the "big reflector in space" solution, it would still take many thousands of years after seeding the planet's atmosphere for it to have a significantly profound impact to permit surface probes.
On the bright side, aramid plastic is very useful as a textile in high temperature environments, and is stronger than kevlar. Oceans of aramid soup would be a very profitable enterprise to harvest and process.
That's basically what I had in mind, except that it wouldn't need ion thrusters if it was sunward of L1, since solar gravity would naturally attract it away from station, and light pressure would push it back on station, only requiring that it adjust its effective aperature to regulate its orbital position. Ion thrusters require fuel. Making use of light pressure and gravity is free*.
It would need solar power to drive its orientational reaction wheels.
It *should* have emergency station keeping thrusters, but they should almost never require firing. Being closer to the sun has other advantages, since it lets you get away with a smaller sheet diameter, further reducing the costs of construction.
Major fault sources would be critical failures of the reaction wheels, and failures of the aperature control systems. Faults in the uniformity of the deployed array (torn fabric, etc) can be compensated for by altering the shape of the aperature.
Instead, I usually have to deal with Airbus (when dealing with metric engineering), who's engineering is so lackluster that their planes fall out of the skyall on their own anyway. (admittedly, the BOEING 787 dreamliner is turning out to be a total spruce goose, given the number of times it has been grounded for faults in the electrical system. Thankfully we don't make parts for that system.)
BOEING/Spirit Aerosystems' engineering is all in imperial distance units and weights, so that isn't an issue for conversions. BOEING's been making aircraft for a good half-century just about, and has a lot of experience in their engineering depts., especially as it relates to design tolerances and material selection. Airbus likes to try to dictate reality and live in hypothetical fantasy land, especially as it relates to actual manufacturability. Sure, the material could theoretically behave as spec'd, but only if you used a startrek replicator.:D Little things like that. (see, the material DOES get hot while milling out that ultra paper thin web of solid titanium, and when it does, the metal grain boundries are mechanically altered, altering the structural properties of the workpiece, and making it more prone to fracture. No, you CANT make it colder, and NO, you cant cut it really really slowly-- Not unless you want to pay for excessive tool wear, which will make your price per unit skyrocket. That's why BOEING limits the number of titanium parts to bare necessity, and why they keep titanium parts as small as possible. Trying to talk with airbus about this is like herding cats. It isn't just for titanium either. Airbus tries to push material selection to the extreme limits on all materials, which doesn't bode well for the craft under repetitive stresses.)
But again, No about the crashy spaceprobe. The stuff we make is for commercial aircraft.
I'd go into details about other snafus from airbus, but I had to sign an NDA. (for real.)
Total quantity of nitrogen gas in the venusian atmosphere is comparable to total quantity of nitrogen gas in the earth's atmosphere. The Venusian atmosphere is simply MUCH denser, and the nitrogen is diluted VERY heavily with CO2.
(Meaning, if you used a compressor and condenser on a "balloon city", you could extract the nitrogen lifting gas by compressing and freezing the CO2, and then dropping it over the side as dry ice. This assumes that the balloon city is floating at 1bar pressure elevations. This is conveniently also above the sulfuric acid cloud tops, meaning sulfuric acid concentrations will be lower.)
One possible solution to the "space weather is erratic!" Problem, is to have the reflector positioned so that it is at "nominal" condition, but not fully deployed, and able to retract while in service.
This way if solar impulse is too low, it can deploy a little further without changing mass, and get more active surface.
Likewise, if there is a large influx of solar wind (cme or something), it can constrict itself by pulling in some of the built in tow lines embedded in the fabric to reduce its surface to match. (It would need these anyway to safely unfurl a sheet that size as it spun up with a reaction wheel.)
Add a small canister of emergency stationing propellent and a multidirectional control nozzel setup, and it could perform station keeping.
Being able to regulate its specific impulse in relation to solar intensity would make this much more feasible.
I knew "off my head" what the imperial transition zone was, since I work in aerospace, and it is useful as an industrial solvent and coolant. Much like many european posters are too lazy to be arsed to look up imperial numbers for things off the tops of their heads, I was too lazy to do the same in the inverse direction. I did however, link to an informative article on wikipedia that gives the metric values for the transition point, assuming you aren't one of those TL;DR types.
I make light of this laziness, and wrapped it in humor.
Specifically, you release sap sucking insects that like to stuff their sharp little noses deep into the tissues of green plants already, such as aphids.
Cross the nitrogen fixating bacteria with wolbachia parasite, so that it can live in both hosts, and watch the plants take over.
That's why you put it "sunward" of the lagrangian point, so that it wants to fall into the sun, but is pushed out of the well by the solar wind.;)
(Exactly where that would be depends on the specific impulse of the solar sail effect, and the mass of the reflector. Since both are hypothetical, I can't really give specifics.)
Slashdot Mirror
I would presume that while the field is quite robust, that the rate of alternation will be either absurdly fast, or very slow.
The first poses a risk of magstrips on credit cards of pedestrians and cyclists being wiped due to hysteresis. (The whole road would be one giant bulk eraser!) The latter makes this less likely, but is less efficient for AC power transfer over long distances of roadbed.
I suspect it will be a slow oscillation based charger, because a moving vehicle trying to get a stable wave for its charging circuit will have "short" moments of interaction with the individual coils in the roadbed as it drives over the top, causing significant headache. This in addition to being less likely to wipe magstrips on credit cards, and the like.
A slow oscillator will be more difficult to draw "large" quantities of electricity from, as the collector would need to be quite large and conspicuous.
Step 1:)
Purchase a waterproof smartphone enclosure from a sporting goods store. Like say, these generic ones. insert the phone inside the protector, and seal it.
Step 2:)
At the local post office, purchase a normal cardboard shipping box. I understand walmart also carries these. Then, buy a can of expanding foam insulation. Squirt the expanding foam insulation into the cardboard box, then, while the foam is still expanding and workable, embed the enclosure inside the foam. (You want to be able to get the phone out of the enclosure later. Keep that in mind.)
Step 3:)
Load the cardboard "shock box" into a "pumpkin chucker" trebuchet. You may need to troll newspapers or craigs list to find someone who has one. (they tend to advertise having them, so all you need to do is look.) Set the angle nigh, then let it rip.
Enoy your ballistic smartphone score.
You should switch to a precision high intensity laser pulse rifle.
Some localized charring, and that's it! Granted, you need to wear the eye protection, and some NIMBYs complain about where the photons end up when you miss, but they are just whiners.
Make it time prohibitive?
Prevent "5ns form posting" with a cooloff time, and also cache submitted forms from an IP address to prevent duplicates.
You can also implement a 50 message per day limit, and reduce as needed to stop spammers.
Filling the box channel with 2 part silicone rubber mix, then chasing it will produce a high precision casting negative of the channel, which can then be easily scanned. (and being rubber, easily extracted from the box channel)
Many software packages permit boolean remove operations, which would allow them to position the 3d scanned rubber impression onto a blank channel way, then boolean remove the negative to get the positive impressions again in the digital model.
Then it's 3D print time.
If they are printed using a laser printer, they *are* antialiased.
The term is "edge enhancement".
See for instance, the useful figures and descriptions of the process seen here
The assertion that laser printers do not perform anti-aliasing is simply untrue. They did it before anyone else did.
No horrible mess? For REAL?
Perhaps you should more closely look into what actually initiated subprime mortgage crisis.
The prevailing theory is that the repeal of the Glass-Steagall, and the implementation of the Commodity Futures Modernization Act of 2000.
Taken from this source, Then president clinton officially stated publicly that Glass-Steagall was no longer appropriate, and began measures to repeal it.
Later, After doing so, then president Href="http://en.wikipedia.org/wiki/Commodity_Futures_Modernization_Act_of_2000">Clinton signed the Commodity Futures Modernization Act of 2000 into law.
So, what mess indeed!
What you are REALLY decrying is Disinflation.
The prices of goods are rising, while the rate of wages remains constant, or slightly decrease with time. At the same time, improvements in production make fewer "high demand" (high pay) jobs available, as companies seek to offset the difference as profit.
Insisting on "Living wages or else!" is one possible solution to disinflation, yes, but is not the best one, since it does NOT resolve the issue of job scarcity while population slowly rises. You WILL eventually reach "Peak McDonalds" in terms of market demand, after which point, hiring more McDonalds people for (by then) 20$/hr is not sensible, and will cost the company money. Result: they just stop hiring, and unemployment rises.
This disinflation is a result of the globalist economy model. American pay is overinflated in comparison to the pay in China, or Bangladesh. Free trade to "bring up" those countries is working-- But at the cost of economically disadvantaging US and other 1st world economies.
As much as I really hate the dirty spectre of nationalism, trade tariffs are a tried and true method of keeping this disinflation from happening, while continuing foreign trade. The tariff for a particular good needs to reflect the difference in cost of production incurred by the foreign production, and the difference in inflation, of the two participating economies.
"Bring up the 2nd and 3rd world", VS "Keep the 1st world." You may pick *ONE*.
Agreed, for each nested brach, complexity increases at LEAST geometrically. (A branch always has at least 2 paths.) However, one may not NEED to know *all* branches.
Say for instance, the behavior you want to modify (we will assume you are a cracker making a memory poking drm defeat patch) is rigidly defined in where it gets called from (by this, I mean what code branches spawn the check). You don't really need to look at the other execution paths, just the ones that trigger the drm check, or better still, the check routine itself that gets called. Having execution jump all over the damned place instead of having it be nice and orderly in memory is basically the "spaghetti code" problem. Its just a bunch of jumps, with (*apparently) no rational scheme behind them.
The program itself needs to reliably know where to jump to, and what (*random) addresses to read and write to. Making a "complex" program be able to have a new "scatter" pattern on each fresh execution still requires a fixed entrypoint to decide which scatter pattern to use, and what data to poke after the scattering so that the code can still execute. This presents a point of attack. It also runs foul of the same complexity problem it attempts to present to the cracker; the more potential scatter patterns, the larger the scattering routine, the harder it is for it to poke all the right spots after the scattering to update all the jump instruction and data read/write addresses. Especially if it attemps to scatter its own data as well.
This is because such scattering has to be done intelligently, otherwise performance of execution will drop like a lead brick on jupiter. Say for instance, it does really dumb scattering, and scatters data for a 64bit unsigned integer as 8 addresses, each of 1 byte length, in a seemingly random jumble in the allocated memory image. Instead of 1 64bit linear read, or 2 sequential 32bit reads, it has to do 8 random 8 bit reads, AND process jump instructions injected by the scrambler, before it can actually perform the computation with that integer. The more complex the program scrambled, and the more complex the scrambler used, the greater the performance penalty will be. This places a hard upper bound on the hardness this approach can give the cracker.
Some VMs have "save state" features.
Let's say we have a program that branches many times, as you describe above. The VM is controlled with a script. On the first pass, it looks for and records all instruction branches on the first program run along with the data compared against for each branch to execute, then reloads the saved state at initial program load, and begins systematically walking and triggering code.
On each pass, it spits out what the CPU did, with what inputs.
Since it is a given that new paths that weren't walked before will have yet more banches, the duty list of paths to walk needs to be amendable at runtime.
It may take a very long time to walk out all of the paths and completely map all code logic, but that then becomes something you turn on and then wander off to go eat a sandwich for. Most packages that will use this kind of obfuscation are going to be small, and the number of paths quite limited. However, very large monolithic executables are going to run into issues on how long it takes to fully map them. At that point, one just needs to ask themselves if they really need to fully map the obfuscated code, or if just certain well-used paths are good enough.
I was thinking more along the lines of "special processor instructions", that make use of quirks of real silicon. Given how intel and amd both have taken to cramming lots of extra devices onto the die, a small "inside the CPU" black box designed for this very application would do the trick just fine, and would likewise ensure its presence on modern rigs.
A virtual machine halting execution would be detected by the running software, because it wouldn't get the proper responses from said black box. You'd have to uncap the cpu, and watch with very specialist equipment.
I am thinking a small asynchronous secondary processor.
One way around this (for reverse engineering) would simply be to run it inside a VM with a built in stack trace debugger, like Bochs.
You can peek at the raw instructions percolating through the VM's emulated CPU that way. The application itself is then the decryption key, since the system has to be able to run the application.
PITA, but I don't see how this is anything more than just a "bigger" speedbump, at least as far as disassembly goes. Now, making said decryption require nasty bits of hardware to thwart using a VM, and clinging tightly to treacherous computing with a TPM and a hardware hypervisor on top of this? That's more dicey.
The question here is... why do this? Is preventing Cracker Jack from the warez scene from simply disabling your "authenticity checks" so horrifically important? That's the major application for this that I really see, besides making epically horrific malware. (Though if you ask me, they are both the same thing.)
Seriously, other than making personal computing become something from communist russia, what is the benefit of this?
This presumes the aliens have a lifespan similar to our own.
Just here on earth, compare:
Lifespan of a fruit fly: about 7 to 14 days.
Time to travel across the US by highway, east to west: 7 to 14 days (depending on traffic and route taken)
What truckers do routinely as a vocation takes an entire lifetime for a fly.
Again, that's just here on earth.
If said aliens have 1000 year lifespans, then they could spend 300 years training for the mission, 300 years to get here from the nearest star, and 300 years to return there, and still have around 100 years to tell the rest of their civilization all about it. (We are assuming some non-trivial fraction of C during travel.)
It would be. That is indisputable.
The sun in a yellow dwarf variable star. Its solar output varies, and can be quite erratic. Its gravitational attraction would vary significantly less.
The issue is which set of problems you want to inherit from such an installation:
1) a constant stream of supply missions to keep the unstable L1 situated reflector on station using reaction mass propellant, spare parts for thruster ports and hose assemblies, and all the related logistics.
2) maintaing a tightrope teetering on an unstable orbital period that is sunward of L1, by dynamically altering the effective aperature of the reflector to dynamically match solar output in relation to solar gravity, and keeping a very watchful eye on the automated aperature control systems to avoid critical mission failure.
I think #2 would be "very challenging", but potentially significantly less expensive over the time frames required to affect substantive change on the venusian environment.
Again, without question or hesitation, the orbit *would* be unstable, and *would* require active, continual corrections.
The difference is that you can use light pressure as the reaction mass, and require much smaller logistical supply line resource allocation.
The platform would need to be able to deploy a significantly larger disc diameter than the "nominal" one, to overpower solar attraction when necessary, and also be able to substantially reduce its disc diameter when necessary, to fall deeper into the solar gravitational well.
That's a problem that can be solved with clever engineering, and would provide an "operational orbit zone" within which it would be able to perform such corrections, but beyond which it would require reaction mass to correct the fault.
The former requires constant and continual use of reaction mass to stay on station.
There is.
There is a manmade plastic called "aramid", which is comprised of nitrogen, carbon, and hydrogen. It has no melting temperature, and has a thermal decomposition temperature of approxmately 500c. (Just a little under the mean surface temperature for venus.) It dissolves, but does not denaturate in strong acids.
Should an atmospheric sulfur cycle bacterium be engineered to make use of this substance for cell walls, their little dead bodies resulting from their "natural" lifecycle would fall into the lower atmosphere, be dissolved in the sulfuric acid cloud layer, and accumulate as complex hydrocarbon compounds suspended in the supercritical CO2 below said layer. Up there, they should mix quite homogenously with the absurdly thick atmosphere, and eventually accumulate enough to precipitate in the solution. By that time, a significant portion of the atmosphere would have been organically processed into heavy, long chain hydrocarbons, resulting in reduced pressures, and reduced surface mean temperatures. Mean surface tempurature only needs to drop about 10c for the plastic molecules to remain thermally stable at the surface, meaning oceans of thick plastic goop would begin to form on the surface as the plastic + anhydrous sulfuric acid rain out.
We could probably initiate this process right now using existing technology. However, much like the "big reflector in space" solution, it would still take many thousands of years after seeding the planet's atmosphere for it to have a significantly profound impact to permit surface probes.
On the bright side, aramid plastic is very useful as a textile in high temperature environments, and is stronger than kevlar. Oceans of aramid soup would be a very profitable enterprise to harvest and process.
That's basically what I had in mind, except that it wouldn't need ion thrusters if it was sunward of L1, since solar gravity would naturally attract it away from station, and light pressure would push it back on station, only requiring that it adjust its effective aperature to regulate its orbital position. Ion thrusters require fuel. Making use of light pressure and gravity is free*.
It would need solar power to drive its orientational reaction wheels.
It *should* have emergency station keeping thrusters, but they should almost never require firing. Being closer to the sun has other advantages, since it lets you get away with a smaller sheet diameter, further reducing the costs of construction.
Major fault sources would be critical failures of the reaction wheels, and failures of the aperature control systems. Faults in the uniformity of the deployed array (torn fabric, etc) can be compensated for by altering the shape of the aperature.
LOL! No. No crashy space probes on my conscience.
Instead, I usually have to deal with Airbus (when dealing with metric engineering), who's engineering is so lackluster that their planes fall out of the sky all on their own anyway. (admittedly, the BOEING 787 dreamliner is turning out to be a total spruce goose, given the number of times it has been grounded for faults in the electrical system. Thankfully we don't make parts for that system.)
BOEING/Spirit Aerosystems' engineering is all in imperial distance units and weights, so that isn't an issue for conversions. BOEING's been making aircraft for a good half-century just about, and has a lot of experience in their engineering depts., especially as it relates to design tolerances and material selection. Airbus likes to try to dictate reality and live in hypothetical fantasy land, especially as it relates to actual manufacturability. Sure, the material could theoretically behave as spec'd, but only if you used a startrek replicator. :D Little things like that. (see, the material DOES get hot while milling out that ultra paper thin web of solid titanium, and when it does, the metal grain boundries are mechanically altered, altering the structural properties of the workpiece, and making it more prone to fracture. No, you CANT make it colder, and NO, you cant cut it really really slowly-- Not unless you want to pay for excessive tool wear, which will make your price per unit skyrocket. That's why BOEING limits the number of titanium parts to bare necessity, and why they keep titanium parts as small as possible. Trying to talk with airbus about this is like herding cats. It isn't just for titanium either. Airbus tries to push material selection to the extreme limits on all materials, which doesn't bode well for the craft under repetitive stresses.)
But again, No about the crashy spaceprobe. The stuff we make is for commercial aircraft.
I'd go into details about other snafus from airbus, but I had to sign an NDA. (for real.)
Another fun fact:
Total quantity of nitrogen gas in the venusian atmosphere is comparable to total quantity of nitrogen gas in the earth's atmosphere. The Venusian atmosphere is simply MUCH denser, and the nitrogen is diluted VERY heavily with CO2.
(Meaning, if you used a compressor and condenser on a "balloon city", you could extract the nitrogen lifting gas by compressing and freezing the CO2, and then dropping it over the side as dry ice. This assumes that the balloon city is floating at 1bar pressure elevations. This is conveniently also above the sulfuric acid cloud tops, meaning sulfuric acid concentrations will be lower.)
One possible solution to the "space weather is erratic!" Problem, is to have the reflector positioned so that it is at "nominal" condition, but not fully deployed, and able to retract while in service.
This way if solar impulse is too low, it can deploy a little further without changing mass, and get more active surface.
Likewise, if there is a large influx of solar wind (cme or something), it can constrict itself by pulling in some of the built in tow lines embedded in the fabric to reduce its surface to match. (It would need these anyway to safely unfurl a sheet that size as it spun up with a reaction wheel.)
Add a small canister of emergency stationing propellent and a multidirectional control nozzel setup, and it could perform station keeping.
Being able to regulate its specific impulse in relation to solar intensity would make this much more feasible.
Can you not recognize a joke when you see one?
I knew "off my head" what the imperial transition zone was, since I work in aerospace, and it is useful as an industrial solvent and coolant. Much like many european posters are too lazy to be arsed to look up imperial numbers for things off the tops of their heads, I was too lazy to do the same in the inverse direction. I did however, link to an informative article on wikipedia that gives the metric values for the transition point, assuming you aren't one of those TL;DR types.
I make light of this laziness, and wrapped it in humor.
Your reaction is stilted and humorless.
Who what?
I said it was CO2 with anhydrous sulfuric acid mixed in! How do you get "steam" from that!?
(Boggled mind!)
For those too lazy:
Wolbachia is a genus of parasitical/symbiotic micro-organisms that infect arthropods, including most insects
Many species of insect that have intimate contact with plants and plant juices harbor this parasite. including aphids
Now, asking if that is "a good idea" or not? That's an entirely different question!
Insects.
Specifically, you release sap sucking insects that like to stuff their sharp little noses deep into the tissues of green plants already, such as aphids.
Cross the nitrogen fixating bacteria with wolbachia parasite, so that it can live in both hosts, and watch the plants take over.
Actually, steam should glow spectacularly in the far IR spectrum.
Clearly, you are unfamiliar with blackbody radiation, and with what the primary absorption/emission bands are for water vapor.
That's why you put it "sunward" of the lagrangian point, so that it wants to fall into the sun, but is pushed out of the well by the solar wind. ;)
(Exactly where that would be depends on the specific impulse of the solar sail effect, and the mass of the reflector. Since both are hypothetical, I can't really give specifics.)