Anyone who can say "only 6000 m/s" with a straight face when talking about post-launch maneuvers has never worked with rocket mass budgets.;) For a single stage, 6000 m/s with a 340s isp and 0.08 inert mass ratio is an over 10:1 scaling factor (aka, for every 10 kg you launch to LEO you get 1kg payload to your destination). Just 3000 m/s is a nearly 3:1 ratio.
Probably better to get some kind of cloud city working on Earth before attempting to go trans-solar-system with the concept.
That would indeed be part of the development process. It's harder on Earth, mind you - a Landis habitat has to be inflated with heliox on Earth, which is much more expensive and permeation-prone. But such a habitat absolutely can be tested on Earth.
By the altitude Venus' atmosphere is more dense than Earth's, it's also highly corrosive.
The sulfuric acid is quite overstated in the popular imagination. It's more like a bad smog (or more accurately, vog) - several to several dozen milligrams per cubic meter, as noted below (also as noted below, OSHA allows people to breathe up to 1mg/m^3 for an entire 8-hour shift). It's much more of a resource than a problem; design work would be simpler if it were denser, not sparser. Material compatibility is easier to ensure (via fluoropolymers) than the scrubber design aspects are; you have to have high mass flow rates because the sulfuric acid is so sparse.
(That said, there was some - disputed - evidence from Vega that there may sometimes be "rain" on Venus. If that's correct, that'd be quite the blessing for resource collection. It's sad how we don't even know such basics as "does it rain on Venus?" at present)
Jupiter is a little too active for my taste, but perhaps Neptune or Uranus might have some attractive latitudes at which to float a city, assuming you bring your own power sources and don't rely on the sun.
The gas and ice giants are tough. They're very, very far, exceedingly hard to get out of, and because they're predominantly hydrogen (80-96%), the Landis design is right out (you can't live in a spacious envelope, you're stuck in a gondola); the envelope has to be hot hydrogen (heated with a lot of energy, because you lose it quickly on those scales). The gas and ice giants also have the wrong ratios of temperature to pressure - too much pressure relative to temperature. Plus, much less diverse gaseous mineral resources, and (effectively) no surface mineral resources at all. And of course as you note, little light. Venus is far better in virtually every respect. Its right next door, the easiest planet to get to, a great location from an orbital dynamics perspective, and it has everything.
I'm with a group called Venus Labs; we'll have our first book out later this year.:) Materials compatibility is a big topic therein. Thankfully, there are a lot of polymers that have good resistance to Venus's environmental conditions (particularly fluoropolymers, although minimizing coating fluorine content is important for ISRU because hydrogen fluoride is a lot less common than hydrogen chloride and sulfuric acid - so for example PCTFE or PVF would be preferable to, for an example, FEP). The sulfuric acid mist isn't actually very concentrated from a particle density perspective - visibility is a couple kilometers. The mist is a couple to several dozen grams per cubic meter, depending on the altitude, latitude, time, etc (by comparison, OSHA allows people to breathe up to 1 mg/m for an 8-hour work shift). But it is concentrated from a molar perspective - on Earth, H2SO4 mists self-dilute with atmospheric water vapour.
Why Venus? Venus has the most Earthlike environment in the solar system outside Earth. High latitudes in the middle cloud layer have Earthlike temperatures, pressures, gravity, sufficient radiation shielding, ample light, and diverse resources already gas phase and only needing to be run through a scrubber to give you feedstocks (even iron, in the form of iron chlorides - estimated at about 1% of the mass of the sulfuric acid - which, by the way, thermally decomposes in the presence of a catalyst to release water and oxygen). Concerning orbital mechanics, Venus ascent stages are of course harder than Mars, but apart from that, it's in a much more favorable spot concerning orbital mechanics, with a much greater Oberth effect and much more frequent launch windows; it can be easier to get payloads to Mars from Venus than from Earth (and can even get gravity assists from Earth). Beyond the abundant solar power, there's also abundant wind power. Normal Earth air is a lifting gas. Unlike a Mars habitat which is a cramped pressure vessel, a Venus habitat is an expansive, open, bright area, full of plants and life. If you don't like someone, go hang your room elsewhere in the envelope, potentially even hundreds of meters away. Bored? Jump into the safety netting; the scale indoors is so big you can basically do indoor skydiving.
As for learning, Venus has vastly more unknown than Mars. Venus is our twin, and the question as to why it ended up the way it did and Earth didn't is one of the great questions in planetary geology. Venus used to have oceans like Earth. Yet today its surface has become this alien place, a veritable natural refinery that bakes and erodes minerals out of the surface and precipitates them out in the clouds. The whole planetary surface, or nearly so, resurfaced itself about 500 million years ago. We have no idea why. Can Earthlike planets just up and do this? If so that's a very disturbing concept. it has the longest river in the solar system - we have no clue what carved it. The best theories are really weird, like natrocarbonatites - super-rare low-temperature lavas that look like oil, flow like water, and glow crimson at night. It has lightning, but we can't seem to find it. It seems to be the second most volcanically active place in the solar system (after Io) but we've never positively confirmed an eruption. There's a huge amount that our planetary models just can't explain. Why doesn't it have an intrinsic magnetic field? Even with its slow rotation speed, dynamo theory says it should; it doesn't. Where's its mercury? Chemical models say that there should be 3 1/2 orders of more in the clouds than the upper detection limits of the probes thusfar constrained it to. What are the strange radar reflective frosts / snows in the highlands? Pyrite? Galena? Tellurium? There seems to be more than one type, too. I could go on for pages and pages here. And there's vastly more reason to have humans present for exploration on Venus, because given the surface conditions, latency for controlling robotic probes is very important - unlike Mars, where communications "downtime" for rovers just gives them more time to charge in the weak sun. And you don't have to worry about degeneration due to low gravity like you do on Mars.
The surface, while hostile, is absolutely accessible. The Soviets had a lot better success probing the surface of Venus than they had Mars. The basic design is very simple: metal shell. insulation, and a material that absorbs heat through a phase change; it can easily buy you a couple hours. Tech developed by the Soviets in the 1960s. It's been determined that you could actually shoot a hollow titanium sphere at Venus, without any kind of heat shield or parachute, and it'd reach the surface intact; that nice "fluffy" atmosphere goes a long way. On Mars you have to have controlled propulsive landings onto rough terrain with little to slow you down - something that continues to randomly kill landers. The surface air o
What is the cost of launching a Mars vehicle directly from Earth?
$7k/kg by Falcon Heavy pricing. Would you rather a different launch system?
Insanely high
Not really. But the problem is your "lowering prices" standards involves having to send things into to an entirely different gravity well (consumables), and landed propulsively, so that other different things can then be launched from said gravity well.
And it has diminishing returns
Your proposal, absolutely.
From Earth, there are no diminishing returns whatsoever. Just the opposite - the more you launch, the cheaper it gets per kg.
There is no practical way to launch a large enough manned vehicle for Mars
One: completely and utterly false. There are a huge number of different proposals for this, all of them technologically feasible.
Two: your counterproposal involves doing the same for the moon, and then doing constant resupply so that they can build things that require an entire industrial base there. It's an absurdity.
Let's take a look at the Falcon Heavy heavy lift vehicle [wikipedia.org] which is one of the heaviest available right now. The payload to Mars is about 13,000 kg. That is about the weight of 1 ISS module.
And?
No, seriously, and? Just ignoring that you can launch to LEO, including transfer stages, and this you actually can launch over 50 tonne segments, is your notion that humans can't build things in space? If not, walk outside tonight when the ISS is due to pass overhead, and look up.
The cost per launch is $90m. Want five launches to build it? Ten? Fifty? You're still a fraction of the cost of establishing the sort of industrial infrastructure needed on the moon to support rocket launches, which in turn is still going to cost more than from the Earth due to the cost of said infrastructure's imports.
Have you ever thought why no NASA missions to outer space has been refueld?
You mean like the ISS?
The ISS station gets refueled all the time but not probes. Why is that?
Because it's cheaper to just build things on Earth and launch them, exactly the point I've been trying to get you to understand this whole time. Doing things in space increases the cost, and the further you are from Earth, the greater that cost is. Work in LEO is expensive because everything requires consumables that must be launched (humans in particular). Work on the moon is vastly moreso because it requires vastly more delta-V to get there. You're wanting to do the vast majority of the work at a place where costs make LEO look like a bargain. Work that can't even be done without developing a whole industrial base to begin with.
By your logic, NASA has no plans for Mars either.
Incorrect, and an absurd statement to make. The "Journey To Mars" program is the core of NASA's focus. (If it wasn't, nobody would ever put MOXIE on Mars 2020.;) )
This is getting absurd. If anyone else wants to talk to this person (who actually goes by the name "UnknowingFool" - almost starting to wonder if this is trolling), go ahead - I'm out.
Nowhere did I say that NASA needs to rebuild and entire installation; however, in terms of fuel cost it is much easier to launch from the Earth to the moon then refuel at the moon
Implicit in saying that is the premise that the moon has an industrial base, because you don't make fuel and launch rockets without an industrial base. And an industrial base means dependency chains. And even importing a very small fraction of the amount from Earth to fill gaps in their dependency chains that they launch from the surface would easily price them out of the market. Never mind the absurd capital costs you have to amortize.
Current NASA plans have the moon as a refueling point
NASA has no plans for a lunar refueling point. It is not part of any actively-being-worked-towards timeline. They've posited the concept before, but they've posited a million fanciful things.
So all the water on the moon that could be used as fuel for Mars missions has no value?
I'd love to see your proposal for launching water from the moon to Mars for less than $7k per kilogram. Include all allocation of labour, all feedstocks production, and all consumables, including system maintenance.
The reason we launch from the Earth is Earth is where our industrial production infrastructure is. And even if you have to import just a couple percent to the Moon of the mass that you could launch from the Moon in payload (aka a highly evolved industrial base), you've blown your budget. Just ignoring that the needs of Mars most definitely aren't water. It's habitats, vehicles, and industrial / manufacturing hardware. Have fun trying to produce that sort of stuff on the moon.
As you note, the tooling for Apollo doesn't exist. The suppliers don't exist. Some parts of the design don't exist any more, and that which does is just on paper. Everything would have to be started over in terms of modern CAD diagrams, full testing, etc. It would be more expensive to recreate Apollo than to make a new system with better performance. Today we have better alloys, better performance designs, more knowledge. And we do have infrastructure and suppliers that exist today, so it makes much more sense to make use of their capabilities than to recreate that which existed in the 1960s.
Your post seems premised on the notion that finding a way to make a big rocket is hard. It's not. There is no shortage of ways to come up with arrangements to reach the moon. The hard part is the low level engineering and testing, both at the component level and integration level. And we don't get that by going with Apollo. We actually lose in that regard, versus going with more modern systems.
Could you describe to me what is the "Obama space malaise"?
Obama didn't want SLS. It was congress that mandated it. And I'm in agreement: SLS is a giant unfunded mandate. "Let's build a rocket that will be way too expensive to make significant use out of, and which we won't have the budget to use often enough to make reliable or at all cheaper".
You don't make mandates that you're not going to fund. So much of congressional NASA mandates have been make-work programs, trying to justify keeping Apollo and Shuttle-era facilities open - the cost of keeping those facilities open inherently making anything that they do very expensive. It's no mystery that they need to cut back and streamline their operations to be competitive. But they're not allowed to.
Honestly, I'd like to see NASA become in many ways NACA again. An science agency with a focus on advanced research projects that help improve aerospace technology and understanding in ways that others can make use of. Now, exploration is in many ways part of that. But "NASA as a rocket manufacturer" strikes me as akin to the government running a passenger jet manufacturer or the like. I see the current situation as totally backwards - why should NASA be redoing the tech of the 1960s, while private companies are the ones doing innovations like first stages that return to pad for reuse? It should be NASA developing new technology and the private sector exploiting it.
And this was the approach that the Obama administration was pushing for, with the very successful COTS program. There are many things I have to fault it for, but this is not one. I mean, seriously, how weird is it that Republicans are pushing for things to be run by a big government agency that does everything internal, and Democrats pushing for greater privatization and outsourcing?;)
While they are different ways to get there, one path is to first establish a moon base and launch from there instead of Earth orbit.
Launch what, exactly, from the Moon?
I think you're confusing "a moon base" with "a full industrial infrastructure capable of producing complex objects". Even the concept that it would be cheaper to launch unrefined raw regolith from the moon cheaper than we can launch equivalent mass payloads from Earth anytime even remotely soon is absurd.
Earth is where industry is. The fact that we're a deep gravity well increases costs, but that difference is nothing compared to the difference in industrial capacities on and off Earth. Every production process has feedstock and consumables dependency chains. Those have dependency chains, and those have further chains, to a massive network of ever-increasing complexity. One of the worst dependencies is humans, which in turn spawn massive dependency chains.
Now, ultimately you can meet these things to the degree that the few things you have to import to sustain local industrial activity (at incredible cost) do not price the cost of local rocket launches out of the market., but if you think that's going to happen any time in the next few decades, you're deluding yourself. The serious proposals for going to the moon before Mars are for the moon to function as a testbed for habitats and systems designed for Mars.
Anyway, I'm personally much more for the habitation of Venus than Mars, but that is neither here nor there:)
Yeah, it's crazy how much they put in them. The human body requires utterly miniscule amounts of B12. But the difference between "miniscule" and "none" has a big impact:)
Vegans do. Vegetarians can get it from milk and eggs.
And hey, that can be turned around if you want to play that game. Your typical American eats var too few vegetables and so misses out on a lot of the plant-associated vitamins and minerals.
All kinds of foods are fortified with all kinds of vitamins
The fact that a particular tofu manufacturer may fortify their product with B12 is only because they know that a lot of their market is vegan. Not all vegans eat tofu, or will pay attention to whether their brand does or does not fortify. Not all eat cereal either (the main "multivitamin-fortified" food that people consume), and a serving of a typical fortified cereal only provides about a quarter of your RDA anyway. Lots of other foods are fortified by specific nutrients, but rarely B12.
A person who doesn't even understand the concept of splitting up paragraphs is in no grounds for criticizing someone else as being "unintelligible". Likewise, starting off a debate by accusing the other side of "psychosis"... well, I'll not comment about what that says about you.
. 1. Your understanding of why water is required for LAWKI is wrong. It's principle properties (as far as LAWKI is concerned) are thought to be A. hydrogen bonding and B. solvency.
1) The presence of water inside a cell does not require that a wet external environment was the source of the hydrogen in said water.
2) There are countless solvents in the universe. Out of sheer coincidence over the past two days I've been reading papers on the solvency properties of ionic liquids and carbon disulfide (the latter being common naturally). The studied possibilities of cyanide chemistry on Titan use methane as a solvent. Ammonia is also common in the universe and is an excellent solvent. (if you want to argue against methane and ammonia because they're not polar, you're going to have to defend the concept that solvents must be polar - which in the studied case for Titan, they absolutely don't have to be in order to create some spectacularly complex cyanide chemistry). Carbon dioxide is a superb solvent in its supercritical state. There are lots and lots of common natural compounds that are excellent solvents in widely varying environments. Not environments that LAWKI would survive in, but that's because LAWKI is evolved to the conditions of Earth, utilizing molecules that are stable on Earth conditions for its life processes.
2. The Drake Equation. I'd speculate that if you sat down and studied the equation *critically*, that you'd see it has major flaws, the most serious (imho) is the assumption that each of its terms can be reduced to numerical values and that each term is independent of the others.
Which can be resolved by combining terms. Feel free to present your alternative (many people have); each form nonetheless invariably projects massive numbers of civilizations.
3. The Fermi Paradox also has serious problems. Let's say that interstellar travel is technically impossible
A premise I'll gladly accept.
- that there's no propulsion technology which can transport viable (sufficiently complex) intelligent life across interstellar distances. Then there is no "paradox"
Except that there still is, because even if a civilization evolved only 1% earlier than ours did (a very tiny margin!), it's 138 million years old, and can thus be expected to have been long moving out at relativistic speeds in all directions. The Milky Way's diameter is only 100-180k light years. Even Andromeda is only 2,5 million light years away. Even civilizations having advanced to the point of interstellar travel just a mere 1% earlier than we've reached our current state should be arriving from all over the local group - let alone ones that developed 5%, 15%, 50%, etc earlier. The fact that life tends to spring up wherever there's water is not consistent with the observed emptiness of the universe.
Cosmological distances help keep is apart, but it is also a requirement that life be very rare.
Another problem can be seen if I use the same reasoning to claim that every square meter of the Earth's surface must have been "visited"
The more appropriate comparison, since we're talking about beings that reproduce, and over timescales representing countless generations, is to claim that every square meter of Earth's surface must have been visited by bacteria. And golly gee, it has. Even ignoring the point that bacteria don't have intelligence to guide them.
Finally, you should account for the stupidity of any group of fans of any meme. The *experts* (
Funny, the only schizophrenic I've ever known was also vegan.
I'm a vegetarian, and have strong sympathy for the motives behind being vegan. But take your B-12, my vegan friends. Unless you eat large amounts of soil, feces, or bacterial concentrates, or you've had a rumen implanted in your body, you need it. Higher plants don't make it. Every "vegetarian" mammal has to get it from somewhere, and those not lucky enough to have rumens (or other organs filling equivalent "cultivate lots of bacteria" roles) either get it through eating soil, feces, insects (accidentally or on purpose), or other such sources. Even our "strict" vegetarian gorilla relatives eat grubs. Heck, even though I consume dairy, I still take a B-12 supplement, just to ensure that I get enough.
Also, B-12 shortage doesn't hit you immediately. The body stores about 5 years of B-12. So it'll catch up with you sooner or later.
When I heard Musk was getting into boring, my mind immediately jumped to: rocket engines. Either to throw abrasives or for simple thermal spall.
If you want to channel a lot of energy in a short period of time at a surface, you can't beat a rocket. Now, getting it to do what you want, and not destroy your hardware, that's the challenge...;)
As for the issue of what we should be looking for, it's hypercycles. Complex interactions of chemicals being driven by an energy source, cycles which might have the potential to "close the loop" and catalyze their own creation. And in that regard, I'd argue that Titan is a more likely place for life than Mars (although I don't expect to find life there, either - but what you can learn from studying the chemistry has so far proven to be fascinating, there's apparently a whole range of cyanide compounds at Titan surface temperatures that can perform the basic steps of all major life processes - even photosynthesis - and in some cases even more effectively than LAWKI can in Earth conditions).
I'd also argue for looking for phenomena that are difficult to explain by other means. For example, some people have pushed the "Martian methane" thing, but that's not particularly compelling, it just means that Mars isn't entirely geologically dead. I've heard a similar non-compelling argument for OCS on Venus. Of the "unknowns" in our solar system, I again think Titan has presented the best case to date, in the fact that multiple lines of evidence show higher hydrocarbons apparently disappearing at the surface, and some evidence (less clear) suggests hydrogen also disappearing at the surface. The this sort of metabolism of theoretical life on Titan - decomposition of higher hydrocarbons with hydrogen - was theorized before the above data was discovered (published right as Huygens was landing, actually). And that's something very difficult to explain by natural reactions at Titan surface temperatures - discovery of a natural catalyst that could do that would itself be an incredible find. There are argued non-life explanations (some sort of method that sequesters higher hydrocarbons underground where we wouldn't detect them - they're not dissolved in the seas, at least, which appear to be pure methane), and due to the Fermi Paradox I expect explanations involving non-life answers to be the correct ones. But, to me at least, Titan certainly seems more compelling than Mars and its destroy-organics-on-contact regolith.
And don't get me wrong, I absolutely want to see what's under the ice in Europa or Enceladus. But I don't expect to see anything swimming. Enceladus appears to have a soda ocean (Mono Lake-style), and I wouldn't be surprised if Europa's is similar. Dead, but potentially with interesting chemical clues.
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Anyone who can say "only 6000 m/s" with a straight face when talking about post-launch maneuvers has never worked with rocket mass budgets. ;) For a single stage, 6000 m/s with a 340s isp and 0.08 inert mass ratio is an over 10:1 scaling factor (aka, for every 10 kg you launch to LEO you get 1kg payload to your destination). Just 3000 m/s is a nearly 3:1 ratio.
That would indeed be part of the development process. It's harder on Earth, mind you - a Landis habitat has to be inflated with heliox on Earth, which is much more expensive and permeation-prone. But such a habitat absolutely can be tested on Earth.
The sulfuric acid is quite overstated in the popular imagination. It's more like a bad smog (or more accurately, vog) - several to several dozen milligrams per cubic meter, as noted below (also as noted below, OSHA allows people to breathe up to 1mg/m^3 for an entire 8-hour shift). It's much more of a resource than a problem; design work would be simpler if it were denser, not sparser. Material compatibility is easier to ensure (via fluoropolymers) than the scrubber design aspects are; you have to have high mass flow rates because the sulfuric acid is so sparse.
(That said, there was some - disputed - evidence from Vega that there may sometimes be "rain" on Venus. If that's correct, that'd be quite the blessing for resource collection. It's sad how we don't even know such basics as "does it rain on Venus?" at present)
The gas and ice giants are tough. They're very, very far, exceedingly hard to get out of, and because they're predominantly hydrogen (80-96%), the Landis design is right out (you can't live in a spacious envelope, you're stuck in a gondola); the envelope has to be hot hydrogen (heated with a lot of energy, because you lose it quickly on those scales). The gas and ice giants also have the wrong ratios of temperature to pressure - too much pressure relative to temperature. Plus, much less diverse gaseous mineral resources, and (effectively) no surface mineral resources at all. And of course as you note, little light. Venus is far better in virtually every respect. Its right next door, the easiest planet to get to, a great location from an orbital dynamics perspective, and it has everything.
I'm with a group called Venus Labs; we'll have our first book out later this year. :) Materials compatibility is a big topic therein. Thankfully, there are a lot of polymers that have good resistance to Venus's environmental conditions (particularly fluoropolymers, although minimizing coating fluorine content is important for ISRU because hydrogen fluoride is a lot less common than hydrogen chloride and sulfuric acid - so for example PCTFE or PVF would be preferable to, for an example, FEP). The sulfuric acid mist isn't actually very concentrated from a particle density perspective - visibility is a couple kilometers. The mist is a couple to several dozen grams per cubic meter, depending on the altitude, latitude, time, etc (by comparison, OSHA allows people to breathe up to 1 mg/m for an 8-hour work shift). But it is concentrated from a molar perspective - on Earth, H2SO4 mists self-dilute with atmospheric water vapour.
"That book"?
Why Venus? Venus has the most Earthlike environment in the solar system outside Earth. High latitudes in the middle cloud layer have Earthlike temperatures, pressures, gravity, sufficient radiation shielding, ample light, and diverse resources already gas phase and only needing to be run through a scrubber to give you feedstocks (even iron, in the form of iron chlorides - estimated at about 1% of the mass of the sulfuric acid - which, by the way, thermally decomposes in the presence of a catalyst to release water and oxygen). Concerning orbital mechanics, Venus ascent stages are of course harder than Mars, but apart from that, it's in a much more favorable spot concerning orbital mechanics, with a much greater Oberth effect and much more frequent launch windows; it can be easier to get payloads to Mars from Venus than from Earth (and can even get gravity assists from Earth). Beyond the abundant solar power, there's also abundant wind power. Normal Earth air is a lifting gas. Unlike a Mars habitat which is a cramped pressure vessel, a Venus habitat is an expansive, open, bright area, full of plants and life. If you don't like someone, go hang your room elsewhere in the envelope, potentially even hundreds of meters away. Bored? Jump into the safety netting; the scale indoors is so big you can basically do indoor skydiving.
As for learning, Venus has vastly more unknown than Mars. Venus is our twin, and the question as to why it ended up the way it did and Earth didn't is one of the great questions in planetary geology. Venus used to have oceans like Earth. Yet today its surface has become this alien place, a veritable natural refinery that bakes and erodes minerals out of the surface and precipitates them out in the clouds. The whole planetary surface, or nearly so, resurfaced itself about 500 million years ago. We have no idea why. Can Earthlike planets just up and do this? If so that's a very disturbing concept. it has the longest river in the solar system - we have no clue what carved it. The best theories are really weird, like natrocarbonatites - super-rare low-temperature lavas that look like oil, flow like water, and glow crimson at night. It has lightning, but we can't seem to find it. It seems to be the second most volcanically active place in the solar system (after Io) but we've never positively confirmed an eruption. There's a huge amount that our planetary models just can't explain. Why doesn't it have an intrinsic magnetic field? Even with its slow rotation speed, dynamo theory says it should; it doesn't. Where's its mercury? Chemical models say that there should be 3 1/2 orders of more in the clouds than the upper detection limits of the probes thusfar constrained it to. What are the strange radar reflective frosts / snows in the highlands? Pyrite? Galena? Tellurium? There seems to be more than one type, too. I could go on for pages and pages here. And there's vastly more reason to have humans present for exploration on Venus, because given the surface conditions, latency for controlling robotic probes is very important - unlike Mars, where communications "downtime" for rovers just gives them more time to charge in the weak sun. And you don't have to worry about degeneration due to low gravity like you do on Mars.
The surface, while hostile, is absolutely accessible. The Soviets had a lot better success probing the surface of Venus than they had Mars. The basic design is very simple: metal shell. insulation, and a material that absorbs heat through a phase change; it can easily buy you a couple hours. Tech developed by the Soviets in the 1960s. It's been determined that you could actually shoot a hollow titanium sphere at Venus, without any kind of heat shield or parachute, and it'd reach the surface intact; that nice "fluffy" atmosphere goes a long way. On Mars you have to have controlled propulsive landings onto rough terrain with little to slow you down - something that continues to randomly kill landers. The surface air o
Precisely.
$7k/kg by Falcon Heavy pricing. Would you rather a different launch system?
Not really. But the problem is your "lowering prices" standards involves having to send things into to an entirely different gravity well (consumables), and landed propulsively, so that other different things can then be launched from said gravity well.
Your proposal, absolutely.
From Earth, there are no diminishing returns whatsoever. Just the opposite - the more you launch, the cheaper it gets per kg.
One: completely and utterly false. There are a huge number of different proposals for this, all of them technologically feasible.
Two: your counterproposal involves doing the same for the moon, and then doing constant resupply so that they can build things that require an entire industrial base there. It's an absurdity.
And?
No, seriously, and? Just ignoring that you can launch to LEO, including transfer stages, and this you actually can launch over 50 tonne segments, is your notion that humans can't build things in space? If not, walk outside tonight when the ISS is due to pass overhead, and look up.
The cost per launch is $90m. Want five launches to build it? Ten? Fifty? You're still a fraction of the cost of establishing the sort of industrial infrastructure needed on the moon to support rocket launches, which in turn is still going to cost more than from the Earth due to the cost of said infrastructure's imports.
You mean like the ISS?
Because it's cheaper to just build things on Earth and launch them, exactly the point I've been trying to get you to understand this whole time. Doing things in space increases the cost, and the further you are from Earth, the greater that cost is. Work in LEO is expensive because everything requires consumables that must be launched (humans in particular). Work on the moon is vastly moreso because it requires vastly more delta-V to get there. You're wanting to do the vast majority of the work at a place where costs make LEO look like a bargain. Work that can't even be done without developing a whole industrial base to begin with.
Incorrect, and an absurd statement to make. The "Journey To Mars" program is the core of NASA's focus. (If it wasn't, nobody would ever put MOXIE on Mars 2020. ;) )
This is getting absurd. If anyone else wants to talk to this person (who actually goes by the name "UnknowingFool" - almost starting to wonder if this is trolling), go ahead - I'm out.
Implicit in saying that is the premise that the moon has an industrial base, because you don't make fuel and launch rockets without an industrial base. And an industrial base means dependency chains. And even importing a very small fraction of the amount from Earth to fill gaps in their dependency chains that they launch from the surface would easily price them out of the market. Never mind the absurd capital costs you have to amortize.
NASA has no plans for a lunar refueling point. It is not part of any actively-being-worked-towards timeline. They've posited the concept before, but they've posited a million fanciful things.
And doing something impressive with it. Those realtime touchdown videos are amazing.
I'd love to see your proposal for launching water from the moon to Mars for less than $7k per kilogram. Include all allocation of labour, all feedstocks production, and all consumables, including system maintenance.
The reason we launch from the Earth is Earth is where our industrial production infrastructure is. And even if you have to import just a couple percent to the Moon of the mass that you could launch from the Moon in payload (aka a highly evolved industrial base), you've blown your budget. Just ignoring that the needs of Mars most definitely aren't water. It's habitats, vehicles, and industrial / manufacturing hardware. Have fun trying to produce that sort of stuff on the moon.
As you note, the tooling for Apollo doesn't exist. The suppliers don't exist. Some parts of the design don't exist any more, and that which does is just on paper. Everything would have to be started over in terms of modern CAD diagrams, full testing, etc. It would be more expensive to recreate Apollo than to make a new system with better performance. Today we have better alloys, better performance designs, more knowledge. And we do have infrastructure and suppliers that exist today, so it makes much more sense to make use of their capabilities than to recreate that which existed in the 1960s.
Your post seems premised on the notion that finding a way to make a big rocket is hard. It's not. There is no shortage of ways to come up with arrangements to reach the moon. The hard part is the low level engineering and testing, both at the component level and integration level. And we don't get that by going with Apollo. We actually lose in that regard, versus going with more modern systems.
Could you describe to me what is the "Obama space malaise"?
Obama didn't want SLS. It was congress that mandated it. And I'm in agreement: SLS is a giant unfunded mandate. "Let's build a rocket that will be way too expensive to make significant use out of, and which we won't have the budget to use often enough to make reliable or at all cheaper".
You don't make mandates that you're not going to fund. So much of congressional NASA mandates have been make-work programs, trying to justify keeping Apollo and Shuttle-era facilities open - the cost of keeping those facilities open inherently making anything that they do very expensive. It's no mystery that they need to cut back and streamline their operations to be competitive. But they're not allowed to.
Honestly, I'd like to see NASA become in many ways NACA again. An science agency with a focus on advanced research projects that help improve aerospace technology and understanding in ways that others can make use of. Now, exploration is in many ways part of that. But "NASA as a rocket manufacturer" strikes me as akin to the government running a passenger jet manufacturer or the like. I see the current situation as totally backwards - why should NASA be redoing the tech of the 1960s, while private companies are the ones doing innovations like first stages that return to pad for reuse? It should be NASA developing new technology and the private sector exploiting it.
And this was the approach that the Obama administration was pushing for, with the very successful COTS program. There are many things I have to fault it for, but this is not one. I mean, seriously, how weird is it that Republicans are pushing for things to be run by a big government agency that does everything internal, and Democrats pushing for greater privatization and outsourcing? ;)
Launch what, exactly, from the Moon?
I think you're confusing "a moon base" with "a full industrial infrastructure capable of producing complex objects". Even the concept that it would be cheaper to launch unrefined raw regolith from the moon cheaper than we can launch equivalent mass payloads from Earth anytime even remotely soon is absurd.
Earth is where industry is. The fact that we're a deep gravity well increases costs, but that difference is nothing compared to the difference in industrial capacities on and off Earth. Every production process has feedstock and consumables dependency chains. Those have dependency chains, and those have further chains, to a massive network of ever-increasing complexity. One of the worst dependencies is humans, which in turn spawn massive dependency chains.
Now, ultimately you can meet these things to the degree that the few things you have to import to sustain local industrial activity (at incredible cost) do not price the cost of local rocket launches out of the market., but if you think that's going to happen any time in the next few decades, you're deluding yourself. The serious proposals for going to the moon before Mars are for the moon to function as a testbed for habitats and systems designed for Mars.
Anyway, I'm personally much more for the habitation of Venus than Mars, but that is neither here nor there :)
With what descent stage? (and preferably ascent stage too ;) )
On the order of 15 micrograms per kilogram. Adult humans need 2.4 micrograms per day.
Thank you kindly :)
I've not seen any reports on clay, but I wouldn't expect as much. It's soil bacteria that produce the B12, so you're looking for organic-rich soils.
Animals that eat clay often do so to help neutralize toxic alkaloids and to get various mineral supplements.
Yeah, it's crazy how much they put in them. The human body requires utterly miniscule amounts of B12. But the difference between "miniscule" and "none" has a big impact :)
Vegans do. Vegetarians can get it from milk and eggs.
And hey, that can be turned around if you want to play that game. Your typical American eats var too few vegetables and so misses out on a lot of the plant-associated vitamins and minerals.
The fact that a particular tofu manufacturer may fortify their product with B12 is only because they know that a lot of their market is vegan. Not all vegans eat tofu, or will pay attention to whether their brand does or does not fortify. Not all eat cereal either (the main "multivitamin-fortified" food that people consume), and a serving of a typical fortified cereal only provides about a quarter of your RDA anyway. Lots of other foods are fortified by specific nutrients, but rarely B12.
Are you suggesting blending together pig genes with mammoth genes to make giant porkchops?
Because if so - neat idea, but it won't work. Mammoths are a species of elephant, and pig and elephant DNA just don't splice.
A person who doesn't even understand the concept of splitting up paragraphs is in no grounds for criticizing someone else as being "unintelligible". Likewise, starting off a debate by accusing the other side of "psychosis"... well, I'll not comment about what that says about you.
1) The presence of water inside a cell does not require that a wet external environment was the source of the hydrogen in said water.
2) There are countless solvents in the universe. Out of sheer coincidence over the past two days I've been reading papers on the solvency properties of ionic liquids and carbon disulfide (the latter being common naturally). The studied possibilities of cyanide chemistry on Titan use methane as a solvent. Ammonia is also common in the universe and is an excellent solvent. (if you want to argue against methane and ammonia because they're not polar, you're going to have to defend the concept that solvents must be polar - which in the studied case for Titan, they absolutely don't have to be in order to create some spectacularly complex cyanide chemistry). Carbon dioxide is a superb solvent in its supercritical state. There are lots and lots of common natural compounds that are excellent solvents in widely varying environments. Not environments that LAWKI would survive in, but that's because LAWKI is evolved to the conditions of Earth, utilizing molecules that are stable on Earth conditions for its life processes.
Which can be resolved by combining terms. Feel free to present your alternative (many people have); each form nonetheless invariably projects massive numbers of civilizations.
A premise I'll gladly accept.
Except that there still is, because even if a civilization evolved only 1% earlier than ours did (a very tiny margin!), it's 138 million years old, and can thus be expected to have been long moving out at relativistic speeds in all directions. The Milky Way's diameter is only 100-180k light years. Even Andromeda is only 2,5 million light years away. Even civilizations having advanced to the point of interstellar travel just a mere 1% earlier than we've reached our current state should be arriving from all over the local group - let alone ones that developed 5%, 15%, 50%, etc earlier. The fact that life tends to spring up wherever there's water is not consistent with the observed emptiness of the universe.
Cosmological distances help keep is apart, but it is also a requirement that life be very rare.
The more appropriate comparison, since we're talking about beings that reproduce, and over timescales representing countless generations, is to claim that every square meter of Earth's surface must have been visited by bacteria. And golly gee, it has. Even ignoring the point that bacteria don't have intelligence to guide them.
A bomb is a lot more than just the fissile material therein.
Funny, the only schizophrenic I've ever known was also vegan.
I'm a vegetarian, and have strong sympathy for the motives behind being vegan. But take your B-12, my vegan friends. Unless you eat large amounts of soil, feces, or bacterial concentrates, or you've had a rumen implanted in your body, you need it. Higher plants don't make it. Every "vegetarian" mammal has to get it from somewhere, and those not lucky enough to have rumens (or other organs filling equivalent "cultivate lots of bacteria" roles) either get it through eating soil, feces, insects (accidentally or on purpose), or other such sources. Even our "strict" vegetarian gorilla relatives eat grubs. Heck, even though I consume dairy, I still take a B-12 supplement, just to ensure that I get enough.
Also, B-12 shortage doesn't hit you immediately. The body stores about 5 years of B-12. So it'll catch up with you sooner or later.
When I heard Musk was getting into boring, my mind immediately jumped to: rocket engines. Either to throw abrasives or for simple thermal spall.
If you want to channel a lot of energy in a short period of time at a surface, you can't beat a rocket. Now, getting it to do what you want, and not destroy your hardware, that's the challenge... ;)
As for the issue of what we should be looking for, it's hypercycles. Complex interactions of chemicals being driven by an energy source, cycles which might have the potential to "close the loop" and catalyze their own creation. And in that regard, I'd argue that Titan is a more likely place for life than Mars (although I don't expect to find life there, either - but what you can learn from studying the chemistry has so far proven to be fascinating, there's apparently a whole range of cyanide compounds at Titan surface temperatures that can perform the basic steps of all major life processes - even photosynthesis - and in some cases even more effectively than LAWKI can in Earth conditions).
I'd also argue for looking for phenomena that are difficult to explain by other means. For example, some people have pushed the "Martian methane" thing, but that's not particularly compelling, it just means that Mars isn't entirely geologically dead. I've heard a similar non-compelling argument for OCS on Venus. Of the "unknowns" in our solar system, I again think Titan has presented the best case to date, in the fact that multiple lines of evidence show higher hydrocarbons apparently disappearing at the surface, and some evidence (less clear) suggests hydrogen also disappearing at the surface. The this sort of metabolism of theoretical life on Titan - decomposition of higher hydrocarbons with hydrogen - was theorized before the above data was discovered (published right as Huygens was landing, actually). And that's something very difficult to explain by natural reactions at Titan surface temperatures - discovery of a natural catalyst that could do that would itself be an incredible find. There are argued non-life explanations (some sort of method that sequesters higher hydrocarbons underground where we wouldn't detect them - they're not dissolved in the seas, at least, which appear to be pure methane), and due to the Fermi Paradox I expect explanations involving non-life answers to be the correct ones. But, to me at least, Titan certainly seems more compelling than Mars and its destroy-organics-on-contact regolith.
And don't get me wrong, I absolutely want to see what's under the ice in Europa or Enceladus. But I don't expect to see anything swimming. Enceladus appears to have a soda ocean (Mono Lake-style), and I wouldn't be surprised if Europa's is similar. Dead, but potentially with interesting chemical clues.