This is the standard canard that can make any technology appear to be more efficient than it is in practice. You can always technically use waste heat for something else. In practice, colocation challenges and/or a lack of demand make this only applicable in specialized circumstances. Reusing waste heat also increases capital costs.
but from a "I want off the grid, even if it costs more" point of view it's great
No, from that perspective, it's plain absurd. Just buy a BEV.
You can power a heavy SUV or jacked-up 4x4 pick-em-up-truck with it, which we won't see with battery power any time soon.
By "not any time soon", you mean "having existed for several decades", right? Even in the CARB era with NiMH battery packs there were electric freight vehicles with up to 30 tonne capacities. Toyota's CARB-era vehicle was an SUV. And li-ion is dramatically more powerful per unit mass than NiMH, and today's motors likewise dramatically more powerful per unit mass.
Hydrogen isn't problematic just because it's a gas, it's also an abnormally prone to leaking, abnormally low energy ignition, and abnormally prone to detonation rather than just deflagration gas. NASA safety regulations require that buildings that deal with more than a couple dozen kilograms at once have their roof designed to be blown off in an explosion.
Someone needs to fix that Wikipedia link. The first reference is only for lead-acid batteries, and the second says nothing about li-ion efficiency.
Slow-charge/discharge li-ions can be over 99% efficient. Even fast-charged ones are usually 92-96% efficient.
As for the energy density of hydrogen gas, that's one of the dumbest arguments that hydrogen proponents ever trot out (see earlier in this thread where I cover it, no need to write that all again).
Hydrogen's advantage is that it is extremely light
Proponents always resort to this stupid comparison. Tell me, when was the last time that you hopped into a cloud of hydrogen and drove it around?
A fuel is not a complete vehicle.
The mass of the best full hydrogen tanks for FCVs are only about 6% hydrogen; the rest is the tank mass. Increasing the pressure only decreases that number - pressure only decreases tank volume, but somewhat increases tank mass per kg hydrogen. On top of tankage, fuel cells have low power densities, and you still have to have a hybrid-sized battery for energy buffering. All of these things are heavy. The net result is that FCVs actually don't get that much better range than BEVs.
The same sort of thing applies when people talk about ICEs versus BEVs, comparing a gas tank to a battery. When was the last time you hopped onboard a gas tank and drove around? ICE vehicles have to have, well, an ICE. Which is a big, heavy chunk of hardware. BEVs are propelled by electric motors, which are much more powerful per unit mass, and they also allow simplifications elsewhere in the drivetrain. ICEs of course win as things stand, but it's nothing like a simple tank mass/battery mass comparison suggests.
In practice, FCVs are much worse than just their electrolysis losses. Fuel cells don't run at optimal efficiency all the time, their optimal efficiencies are still lossy, and there's other losses in the system. As a general rule, an FCV gets half or less as much range per unit energy put in.
We're still not very good with the oxygen side of the equation. If you're willing to not take half of your reaction from the air, then you can use chemicals that don't have overvoltage issues on the oxidizer end - for example, hydrogen/chlorine and hydrogen/bromine fuel cells are readily reversible and yield ~90% efficiency, as well as higher power densities and cheaper electrodes. But when you have tanks of both reactants and running power through in both directions then they're no longer considered fuel cells, they're considered flow batteries.
This is not true. Switchgrass is not used to any significant extent for ethanol production.
And really, what do you think people were using dent corn for before? Do you think they just stopped using it? Dent corn isn't eaten as corn-on-the-cob, but it's used for animal feed, making corn oil, corn syrup, corn starch, etc. Do you think people just stopped consuming meat and corn products? And instead are getting their energy and nutrition from air?
Bulk commercial electrolysis hydrogen is terribly expensive - generally over $4/kg wholesale, about $6/kg retail (1kg hydrogen in a FCV gives a range of about 2x that of a gallon of gasoline in a non-hybrid), without any significant fuel taxes (unlike gasoline). Home-scale electrolysis will be inherently less efficient, and home users pay much higher electricity rates than industrial users. They avoid distribution costs/profit, but overall they're going to spend a lot more.
Home NG reforming is cheaper, but 1) it uses a fossil fuel, and 2) generally NG-reformed hydrogen can't be used with FCVs, the purity requirements for FCVs are pretty extreme.
Am I the only one here who thinks what they're doing is great? It might even lead to a small space race with Pakistan - if they succeed, Pakistan isn't going to be happy with India having cheap access to space but not them. And the space race turned out to be a great pressure release valve between the US and USSR.
That said, a second-stage reusable isn't enough - they'll also need a reusable first stage that's cheap to refurbish for relaunch. But that, too, is potentially achievable.
At orbital velocity (LEO) an object has a potential energy of around 30MJ per kilogram, an energy density higher than ethanol. Black powder, by contrast (common in fireworks) has 1/10th that energy density. The various colours, with the exception of white, are generally from rather weakly combusting compounds. There's a lot more energy to be had for producing "glow" from the orbital energy rather than whatever they want to burn to produce a coloured glow. And the colour of the thermal radiation from reentry will depend on the surface temperature, and that's customizeable for red, orange, yellow, and white (no green, blue or purple, though) just through simple blackbody emission, customizeable if specific ions are being ablated that tend to radiate in certain bands. The blackbody colour can be varied over the course of reentry by changing the drag coefficient as the surface ablates.
Perhaps "combustion" is the wrong term, perhaps they're just talking about ablation?
Honestly, you don't need special pellets to make a neat fireworks display, rockets can do that themselves;) In fact... hmm... now that I think about it, the most cost-efficient way to get strange atmospheric effects might be barium clouds. They only require sounding rockets, the glow comes from the below-horizon sun itself, they show effects of the solar wind on the atmosphere (sort of like artificial auroras), and are often mistaken for UFOs and can look like slow fireworks when they expand.
There's this real effort to portray it as more Earth-like, but I'm not buying it.
Let's just look first at that big deal made about the findings of atomic oxygen. Atomic oxygen occurs almost everywhere in the solar system. Wherever solar wind hits water vapour or ice, you get atomic oxygen. It's a complete nothing story.
The whole thing about "signs of flowing water"? It's beyond an exaggeration to call that "flowing water". A better description would be "transient flows of organics-destroying rocket propellant". Those perchlorate flows are what you would use to destroy LAWKI, not create it.
As for "boiling water possibly shaping Mars" - not any time recently. Our global data on Mars suggests that, at least within a couple hundred meters of the surface, there is no liquid groundwater on Mars.
I've seen other things both about the past and present making wild claims as well. For example, some people making a big deal about how "Mars had a past oxygenated atmosphere and life!" because they found a manganese "rock varnish", and such rock varnishes need a strong oxidizer like oxygen. Never mind that if you actually read the paper they point out that Mars's near-ubiquitous perchlorates are also powerful enough oxidizers. They didn't find them at that exact location at that exact time, but seriously, as if that's supposed to mean anything? They talked about how the "varnish" was just a thin coating and made a big deal of it. Except they found it in a known geothermal area. Geothermal springs depositing thin coatings on rocks is what they do.
Another one: the "methane on Mars". Class this one under the "atomic oxygen" category. They've found tiny amounts of methane. You know, the gas released by volcanism, on a planet that has the largest volcano in the solar system. An amount that would be associated with only a small fraction as much volcanic activity as Earth. An amount that could be readily trapped in permafrosts and seasonally escape. No evidence at all that it matches a life-related isotopic signature. Usually undetectable on the surface. Wow, color me impressed.;)
All of these grasping at straws things come amidst a wealth of data that shows Mars to be a terrible place to look for life. No liquid water anywhere near the surface. Organics-destroying compounds ubiquitous in the environment. Meaning not only that they would have destroyed any LAWKI present, but that they're not finding anything organic to react with faster than the (slow) rate that they're created, and that no unusual exotic form of life is consuming them either. Minerals in forms rare or nonexistent on Earth in nature, even in ancient layers, suggesting that even then the environment was not Earthlike.
We've been obsessing over "life on Mars" for long enough. If we want to find life in our solar system, our best bets are subsurface oceans (Europa, Enceladus, Titan, etc). Or perhaps non-LAWKI on Titan's surface.
Does anyone even know which Kurdish group is getting this money? The Kurds in the northeast are 75% fighting against Daesh, 25% against Assad and are working with the US. The Kurds in the northwest (Afrin-area) are 100% fighting against the anti-Assad, anti-Daesh arab rebel groups (both islamic and FSA), often alongside Assad's forces, and have been supplied by the Russians. They nearly cut off the rebels' northern supply lines under Russian air cover until Turkey stopped them with cross-border fire. The net result of their actions is that Daesh has become much stronger in area east of Azaz and has overrun a number of refugee camps, to devastating effect.
For those on the other side of the pond who've never heard of it, the world's largest annual music competition - Eurovision - just voted a muslim woman as the winner. Of course, that was more a slam at Russia than anything else, since she's a Tatar and was singing about how the Russians ethnically cleansed her great grandmother.
Most of the cost of developing for Venus is directly applicable to elsewhere. The interplanetary transfer stage, for example - one of if not the most expensive component to develop - would be pretty much identical to that used for Mars. The basic starting resource extraction trees are quite different for both bodies (generally easier on Venus), but after that, they merge together - same process for the Sabatier reaction, for UHMWPE synthesis, for Haber, for Ostwald, etc. Everything related to "long-term human habitation far from Earth" applies to them both, from medicine to livestock, from birth control to toilet paper. There's a huge amount of things that you need for anywhere you might want to live long-term. Superlight collapsible ovens/microwaves and refrigerators. Ultracompact, efficient cryogenic refrigeration systems (ex. magnetocaloric). Lightweight/metal-free wiring possibilities, like CurTran's CNT "LiteWire". The list is thousands of entries long.
Yes, Venus and Martian habitats are very different structures, and the starts of their resource production trees very different. And Mars presents many extra challenges that Venus does not, while Venus presents some that Mars does not. But both share a tremendous amount of heritage.
As for ISRU proof-of-concept on Venus, that requires a probe. Such a mission could be funded today at little cost if there was will for it. Maybe even Discovery-class. The same mission could likewise do a ballute-entry test, even if relying on helium as a secondary inflation gas, and significantly advance the TRL on that.
Of course, there's a great deal more data gathering and testing than just those things that needs to be done before a manned mission could be launched. You need much better gas/mist analysis, better turbulence modeling, an actual understanding of Venus lightning (more than "it exists, at some unknown layer of the planet, at some times for unknown reasons", which is basically our understanding right now), better materials tolerance data, better precipitation / condensation data, etc. There's a number of missions in the pipes for these sorts of things, although it depends on where the funding goes. On Earth you need to make a reduced-scale demonstrator and actually fly it for long periods (at least several months), using heliox rather than normal air - first unmanned, then manned. You also need to launch a demonstrator into a reentry trajectory to test the full-scale deployment. Thankfully, Earth's and Venus's outer atmospheres and gravity are so similar that it makes this sort of testing easy.
Neither a Venus nor Mars mission are just around the corner. IRSU is also exceedingly important to Mars missions, and we're just barely getting started with that as well. But it's harder to do. I was just reading a paper the other day on the current prospects for local water production, of the five different techniques they're looking at (plus many more that they had to simply rule out), none have any maturity whatsoever, nor have appropriate reserves for them been found and quantified. Like Venus, it's a case of "we know how to do it, from a technical level". Like Venus, the hardware doesn't yet exist, but we know a general path we'd take to build it. But unlike Venus, consistently sourcing process-effective raw materials is far more challenging. Glaciers are usually under too much overburden for strip mining, and in-situ extraction is in an exceedingly early stage at this point. In-situ mining poses the risk of collapse pits forming underneath / near the miner, while strip mining leads to sublimation. The glaciers are believed to generally be full of some unknown mixture of rock and sand of unknown, inconsistent qualities. Much of the solid ice is brine. All of the ice is expected to contain dust, which on Mars is toxic, and contains compounds like perchlorates that are prone to messing up RO membranes even after distillation. The non-glacial techniques involve sulfate minerals (such as gypsum), phyllosilicates (clays), and
Figuring out a chemical process to do X does not go obsolete. Figuring out where a resource Y is located on another world and characterizing it does not go obsolete. Finding out what materials can withstand offworld environments does not go obsolete. On and on and on.
You're confusing basic engineering with "locking down hardware systems to specific lists of specific manufactured components". There's vast amounts of the former that need to be done before we can even think about the latter.
When launch costs are $25/kg
I'm a big fan of work toward cost reduction, and advocated for it above. But these sort of costs are in fantasy dream-world for the foreseeable future.
A falcon 9 costs ~$60M/vehicle, the same price as a B737. Their complexity is roughly the same and BA builds 50 737s/month.
The cost of building the rocket is only about 60% of their total launch costs. Hence why the planned discount for reuse is only about 30%.
I always found the most fun with Doom in using the editors. I liked guns that shot out angry enemies with hacked reduced turning radii, making them like guided missiles. Oh, and I spent way too much time hacking the graphics. Rockets had big smileys and writing that said "Have a nice day". Imps shot signs asking you about how your children are doing. Oh geez, I wish I still had a copy of all of the changes I made....
Most games back in the day you had to hack with a hex editor. So, I mean, it was fun changing the text in Heroes of Might and Magic so that you'd encounter things like a "Cuddle of Kittens" or a "Basket of Muppets" or whatnot. I even changed the game "Worms" to be "Wyrms", with all of the text therein modified. But random hex editing just didn't enable the sort of depths of changes that one could do to Doom with the editors.
Maybe we should jazz up the titles of the other ones to get more people to read them. May I recommend "Harry Potter and the History of Poland (1945-89)"?
Out of curiosity, what are your back-of-the-envelope calculations? Rocket costs don't generally lend themselves very readily to such things, so I'm curious;)
Do you think humans will never settle off-world? Or just "not now"? Because habitation engineering does not mean "now" it means laying the groundwork for the future.
Yes, that would be me;) I haven't posted an update recently, but I've definitely been working on it further. It's a really addictive project, because with each aspect you start researching / doing calculations on, you find subtopics that need the same thing... and subtopics on subtopics, and so on down the line;)
I've found a group of other people who are doing the same and there's been some talk of establishing a Venus Society (equivalent to the Mars Society) later this year. Honestly, there's a lot of systems that Venus and Mars programs could do together, so long as there's recognition of Venus as a valid target to work towards. In fact, one of the most expensive systems of a Mars program (the interplanetary crew transfer stage) could operate quite well for both planets (less delta-V for Venus, significantly shorter transfer times), so long as they make a couple simple design decisions so that it's capable of both Venus and Mars/Earth aerocapture, not just Mars/Earth, and likewise can handle the solar load near Venus.
NASA needs a huge haircut on personnel and facilities related to "launching giant rockets which they can't afford", and a corresponding expansion round in robotic exploration, advanced concepts (aka cost reduction) engineering/testing, and long-term off-planet habitation engineering.
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This is the standard canard that can make any technology appear to be more efficient than it is in practice. You can always technically use waste heat for something else. In practice, colocation challenges and/or a lack of demand make this only applicable in specialized circumstances. Reusing waste heat also increases capital costs.
No, from that perspective, it's plain absurd. Just buy a BEV.
By "not any time soon", you mean "having existed for several decades", right? Even in the CARB era with NiMH battery packs there were electric freight vehicles with up to 30 tonne capacities. Toyota's CARB-era vehicle was an SUV. And li-ion is dramatically more powerful per unit mass than NiMH, and today's motors likewise dramatically more powerful per unit mass.
With even less efficiency and shorter range than FCVs.
And fuel cells even shorter lifespans.
And fuel cells are even more expensive (by a very large margin).
Was there a point you were trying to make?
Yes. Most of the universe.
Jupiter is mostly hydrogen. Seen it exploding any time recently?
Hydrogen isn't problematic just because it's a gas, it's also an abnormally prone to leaking, abnormally low energy ignition, and abnormally prone to detonation rather than just deflagration gas. NASA safety regulations require that buildings that deal with more than a couple dozen kilograms at once have their roof designed to be blown off in an explosion.
Someone needs to fix that Wikipedia link. The first reference is only for lead-acid batteries, and the second says nothing about li-ion efficiency.
Slow-charge/discharge li-ions can be over 99% efficient. Even fast-charged ones are usually 92-96% efficient.
As for the energy density of hydrogen gas, that's one of the dumbest arguments that hydrogen proponents ever trot out (see earlier in this thread where I cover it, no need to write that all again).
Proponents always resort to this stupid comparison. Tell me, when was the last time that you hopped into a cloud of hydrogen and drove it around?
A fuel is not a complete vehicle.
The mass of the best full hydrogen tanks for FCVs are only about 6% hydrogen; the rest is the tank mass. Increasing the pressure only decreases that number - pressure only decreases tank volume, but somewhat increases tank mass per kg hydrogen. On top of tankage, fuel cells have low power densities, and you still have to have a hybrid-sized battery for energy buffering. All of these things are heavy. The net result is that FCVs actually don't get that much better range than BEVs.
The same sort of thing applies when people talk about ICEs versus BEVs, comparing a gas tank to a battery. When was the last time you hopped onboard a gas tank and drove around? ICE vehicles have to have, well, an ICE. Which is a big, heavy chunk of hardware. BEVs are propelled by electric motors, which are much more powerful per unit mass, and they also allow simplifications elsewhere in the drivetrain. ICEs of course win as things stand, but it's nothing like a simple tank mass/battery mass comparison suggests.
In practice, FCVs are much worse than just their electrolysis losses. Fuel cells don't run at optimal efficiency all the time, their optimal efficiencies are still lossy, and there's other losses in the system. As a general rule, an FCV gets half or less as much range per unit energy put in.
We're still not very good with the oxygen side of the equation. If you're willing to not take half of your reaction from the air, then you can use chemicals that don't have overvoltage issues on the oxidizer end - for example, hydrogen/chlorine and hydrogen/bromine fuel cells are readily reversible and yield ~90% efficiency, as well as higher power densities and cheaper electrodes. But when you have tanks of both reactants and running power through in both directions then they're no longer considered fuel cells, they're considered flow batteries.
This is not true. Switchgrass is not used to any significant extent for ethanol production.
And really, what do you think people were using dent corn for before? Do you think they just stopped using it? Dent corn isn't eaten as corn-on-the-cob, but it's used for animal feed, making corn oil, corn syrup, corn starch, etc. Do you think people just stopped consuming meat and corn products? And instead are getting their energy and nutrition from air?
More than that....
Bulk commercial electrolysis hydrogen is terribly expensive - generally over $4/kg wholesale, about $6/kg retail (1kg hydrogen in a FCV gives a range of about 2x that of a gallon of gasoline in a non-hybrid), without any significant fuel taxes (unlike gasoline). Home-scale electrolysis will be inherently less efficient, and home users pay much higher electricity rates than industrial users. They avoid distribution costs/profit, but overall they're going to spend a lot more.
Home NG reforming is cheaper, but 1) it uses a fossil fuel, and 2) generally NG-reformed hydrogen can't be used with FCVs, the purity requirements for FCVs are pretty extreme.
Congrats to them!
Am I the only one here who thinks what they're doing is great? It might even lead to a small space race with Pakistan - if they succeed, Pakistan isn't going to be happy with India having cheap access to space but not them. And the space race turned out to be a great pressure release valve between the US and USSR.
That said, a second-stage reusable isn't enough - they'll also need a reusable first stage that's cheap to refurbish for relaunch. But that, too, is potentially achievable.
One thing that bugs me about this summary:
At orbital velocity (LEO) an object has a potential energy of around 30MJ per kilogram, an energy density higher than ethanol. Black powder, by contrast (common in fireworks) has 1/10th that energy density. The various colours, with the exception of white, are generally from rather weakly combusting compounds. There's a lot more energy to be had for producing "glow" from the orbital energy rather than whatever they want to burn to produce a coloured glow. And the colour of the thermal radiation from reentry will depend on the surface temperature, and that's customizeable for red, orange, yellow, and white (no green, blue or purple, though) just through simple blackbody emission, customizeable if specific ions are being ablated that tend to radiate in certain bands. The blackbody colour can be varied over the course of reentry by changing the drag coefficient as the surface ablates.
Perhaps "combustion" is the wrong term, perhaps they're just talking about ablation?
Honestly, you don't need special pellets to make a neat fireworks display, rockets can do that themselves ;) In fact... hmm... now that I think about it, the most cost-efficient way to get strange atmospheric effects might be barium clouds. They only require sounding rockets, the glow comes from the below-horizon sun itself, they show effects of the solar wind on the atmosphere (sort of like artificial auroras), and are often mistaken for UFOs and can look like slow fireworks when they expand.
I've detected evidence of the complete text of the Wikipedia article on paraedolia carved into the surface of Mars. ;)
There's this real effort to portray it as more Earth-like, but I'm not buying it.
Let's just look first at that big deal made about the findings of atomic oxygen. Atomic oxygen occurs almost everywhere in the solar system. Wherever solar wind hits water vapour or ice, you get atomic oxygen. It's a complete nothing story.
The whole thing about "signs of flowing water"? It's beyond an exaggeration to call that "flowing water". A better description would be "transient flows of organics-destroying rocket propellant". Those perchlorate flows are what you would use to destroy LAWKI, not create it.
As for "boiling water possibly shaping Mars" - not any time recently. Our global data on Mars suggests that, at least within a couple hundred meters of the surface, there is no liquid groundwater on Mars.
I've seen other things both about the past and present making wild claims as well. For example, some people making a big deal about how "Mars had a past oxygenated atmosphere and life!" because they found a manganese "rock varnish", and such rock varnishes need a strong oxidizer like oxygen. Never mind that if you actually read the paper they point out that Mars's near-ubiquitous perchlorates are also powerful enough oxidizers. They didn't find them at that exact location at that exact time, but seriously, as if that's supposed to mean anything? They talked about how the "varnish" was just a thin coating and made a big deal of it. Except they found it in a known geothermal area. Geothermal springs depositing thin coatings on rocks is what they do.
Another one: the "methane on Mars". Class this one under the "atomic oxygen" category. They've found tiny amounts of methane. You know, the gas released by volcanism, on a planet that has the largest volcano in the solar system. An amount that would be associated with only a small fraction as much volcanic activity as Earth. An amount that could be readily trapped in permafrosts and seasonally escape. No evidence at all that it matches a life-related isotopic signature. Usually undetectable on the surface. Wow, color me impressed. ;)
All of these grasping at straws things come amidst a wealth of data that shows Mars to be a terrible place to look for life. No liquid water anywhere near the surface. Organics-destroying compounds ubiquitous in the environment. Meaning not only that they would have destroyed any LAWKI present, but that they're not finding anything organic to react with faster than the (slow) rate that they're created, and that no unusual exotic form of life is consuming them either. Minerals in forms rare or nonexistent on Earth in nature, even in ancient layers, suggesting that even then the environment was not Earthlike.
We've been obsessing over "life on Mars" for long enough. If we want to find life in our solar system, our best bets are subsurface oceans (Europa, Enceladus, Titan, etc). Or perhaps non-LAWKI on Titan's surface.
Does anyone even know which Kurdish group is getting this money? The Kurds in the northeast are 75% fighting against Daesh, 25% against Assad and are working with the US. The Kurds in the northwest (Afrin-area) are 100% fighting against the anti-Assad, anti-Daesh arab rebel groups (both islamic and FSA), often alongside Assad's forces, and have been supplied by the Russians. They nearly cut off the rebels' northern supply lines under Russian air cover until Turkey stopped them with cross-border fire. The net result of their actions is that Daesh has become much stronger in area east of Azaz and has overrun a number of refugee camps, to devastating effect.
For those on the other side of the pond who've never heard of it, the world's largest annual music competition - Eurovision - just voted a muslim woman as the winner. Of course, that was more a slam at Russia than anything else, since she's a Tatar and was singing about how the Russians ethnically cleansed her great grandmother.
Or at least improvements in meat-flavoured toast spreads.
Most of the cost of developing for Venus is directly applicable to elsewhere. The interplanetary transfer stage, for example - one of if not the most expensive component to develop - would be pretty much identical to that used for Mars. The basic starting resource extraction trees are quite different for both bodies (generally easier on Venus), but after that, they merge together - same process for the Sabatier reaction, for UHMWPE synthesis, for Haber, for Ostwald, etc. Everything related to "long-term human habitation far from Earth" applies to them both, from medicine to livestock, from birth control to toilet paper. There's a huge amount of things that you need for anywhere you might want to live long-term. Superlight collapsible ovens/microwaves and refrigerators. Ultracompact, efficient cryogenic refrigeration systems (ex. magnetocaloric). Lightweight/metal-free wiring possibilities, like CurTran's CNT "LiteWire". The list is thousands of entries long.
Yes, Venus and Martian habitats are very different structures, and the starts of their resource production trees very different. And Mars presents many extra challenges that Venus does not, while Venus presents some that Mars does not. But both share a tremendous amount of heritage.
As for ISRU proof-of-concept on Venus, that requires a probe. Such a mission could be funded today at little cost if there was will for it. Maybe even Discovery-class. The same mission could likewise do a ballute-entry test, even if relying on helium as a secondary inflation gas, and significantly advance the TRL on that.
Of course, there's a great deal more data gathering and testing than just those things that needs to be done before a manned mission could be launched. You need much better gas/mist analysis, better turbulence modeling, an actual understanding of Venus lightning (more than "it exists, at some unknown layer of the planet, at some times for unknown reasons", which is basically our understanding right now), better materials tolerance data, better precipitation / condensation data, etc. There's a number of missions in the pipes for these sorts of things, although it depends on where the funding goes. On Earth you need to make a reduced-scale demonstrator and actually fly it for long periods (at least several months), using heliox rather than normal air - first unmanned, then manned. You also need to launch a demonstrator into a reentry trajectory to test the full-scale deployment. Thankfully, Earth's and Venus's outer atmospheres and gravity are so similar that it makes this sort of testing easy.
Neither a Venus nor Mars mission are just around the corner. IRSU is also exceedingly important to Mars missions, and we're just barely getting started with that as well. But it's harder to do. I was just reading a paper the other day on the current prospects for local water production, of the five different techniques they're looking at (plus many more that they had to simply rule out), none have any maturity whatsoever, nor have appropriate reserves for them been found and quantified. Like Venus, it's a case of "we know how to do it, from a technical level". Like Venus, the hardware doesn't yet exist, but we know a general path we'd take to build it. But unlike Venus, consistently sourcing process-effective raw materials is far more challenging. Glaciers are usually under too much overburden for strip mining, and in-situ extraction is in an exceedingly early stage at this point. In-situ mining poses the risk of collapse pits forming underneath / near the miner, while strip mining leads to sublimation. The glaciers are believed to generally be full of some unknown mixture of rock and sand of unknown, inconsistent qualities. Much of the solid ice is brine. All of the ice is expected to contain dust, which on Mars is toxic, and contains compounds like perchlorates that are prone to messing up RO membranes even after distillation. The non-glacial techniques involve sulfate minerals (such as gypsum), phyllosilicates (clays), and
Figuring out a chemical process to do X does not go obsolete. Figuring out where a resource Y is located on another world and characterizing it does not go obsolete. Finding out what materials can withstand offworld environments does not go obsolete. On and on and on.
You're confusing basic engineering with "locking down hardware systems to specific lists of specific manufactured components". There's vast amounts of the former that need to be done before we can even think about the latter.
I'm a big fan of work toward cost reduction, and advocated for it above. But these sort of costs are in fantasy dream-world for the foreseeable future.
The cost of building the rocket is only about 60% of their total launch costs. Hence why the planned discount for reuse is only about 30%.
I always found the most fun with Doom in using the editors. I liked guns that shot out angry enemies with hacked reduced turning radii, making them like guided missiles. Oh, and I spent way too much time hacking the graphics. Rockets had big smileys and writing that said "Have a nice day". Imps shot signs asking you about how your children are doing. Oh geez, I wish I still had a copy of all of the changes I made....
Most games back in the day you had to hack with a hex editor. So, I mean, it was fun changing the text in Heroes of Might and Magic so that you'd encounter things like a "Cuddle of Kittens" or a "Basket of Muppets" or whatnot. I even changed the game "Worms" to be "Wyrms", with all of the text therein modified. But random hex editing just didn't enable the sort of depths of changes that one could do to Doom with the editors.
Maybe we should jazz up the titles of the other ones to get more people to read them. May I recommend "Harry Potter and the History of Poland (1945-89)"?
Out of curiosity, what are your back-of-the-envelope calculations? Rocket costs don't generally lend themselves very readily to such things, so I'm curious ;)
Do you think humans will never settle off-world? Or just "not now"? Because habitation engineering does not mean "now" it means laying the groundwork for the future.
Yes, that would be me ;) I haven't posted an update recently, but I've definitely been working on it further. It's a really addictive project, because with each aspect you start researching / doing calculations on, you find subtopics that need the same thing... and subtopics on subtopics, and so on down the line ;)
I've found a group of other people who are doing the same and there's been some talk of establishing a Venus Society (equivalent to the Mars Society) later this year. Honestly, there's a lot of systems that Venus and Mars programs could do together, so long as there's recognition of Venus as a valid target to work towards. In fact, one of the most expensive systems of a Mars program (the interplanetary crew transfer stage) could operate quite well for both planets (less delta-V for Venus, significantly shorter transfer times), so long as they make a couple simple design decisions so that it's capable of both Venus and Mars/Earth aerocapture, not just Mars/Earth, and likewise can handle the solar load near Venus.
Wholeheartedly agree.
NASA needs a huge haircut on personnel and facilities related to "launching giant rockets which they can't afford", and a corresponding expansion round in robotic exploration, advanced concepts (aka cost reduction) engineering/testing, and long-term off-planet habitation engineering.