Also note that if you were to concentrate Martian air to 1ATM and simply add oxygen to reach an Earthlike O2 partial pressure, it would be highly toxic. 1% CO2 causes drowsiness, while 7-10% is lethal. Also, Mars's atmosphere is 0.0557% carbon monoxide, which while not acutely lethal is well above the toxicity limit where acute symptoms and irreversible, accumulative neurological damage occurs.
Because Venus sure as hell isn't any better (92 times the atmospheric pressure, 400 degrees hotter, sulphuric acid clouds, etc.)
Venus is far better than Mars. Specifically, Venus's cloudtops - say, 54km altitude, 70 latitude (poleward might be even better, but you start facing more risk from the polar vortices, so we'll just compare 70). Earth by comparison will be equatorial, and Mars will be surface-average.
Magnetic field: Earth: 25-65uT, intrinsic; Mars: induced, 20-40nT MPR, 5-20nt magnetosheath; Venus: induced, 40-80 nT MPR, 10-40nT magnetosheath
Health hazards: Earth: those humans evolved to; Mars: 1) Fine, abrasive electrostatic dust, 2) silicosis; 3) perchlorates; 4) hexavalent chromium; 5) other chemical hazards; Venus: 1) Corrosive acid mists; 2) hydrogen fluoride; 3) probably others of relevance
Other local hazards: Earth: those humans evolved to; Mars: marsquakes, landslides, dust storms, probably others. Venus: poorly understood - lightning (although we don't know at what altitude), gusts/shear (probably Earthlike, but poorly quantified), icing (probably not, but maybe), possibly others. Needs more study, but Mars gets the lion's share of the planetary exploration budget and everything else competes for the scraps.
Delta-V to habitable area from LEO (km/s, aerocapture assumed): Earth: 0; Mars: 4.7; Venus: 4.2
Delta-V from habitable area to LEO (km/s, aerocapture assumed): Earth: 9.8; Mars: 10.0; Venus: 15.5
Transit time (months): Earth: 0; Mars: 9; Venus: 5
Launch window frequency (months): Earth: 0; Mars: 25; Venus: 19
Landing difficulty: Earth: moderate (dense atmosphere, oceans to land in, compacting soil, readily available rescue); Mars: hard (reversed conditions of Earth): Venus: easy (no landing at all; your landing ellipse is "a large chunk of the planet")
Solar energy (29% triple-junction W/m): Earth: 290; Mars: 45; sometimes almost none; Venus: 400
Capturable wind energy: Earth: moderate; Mars: effectively none; Venus: high
Diversity / value of resources: Earth: moderate (that which we're used to); Mars: probably less than Earth, but not "poor"; Venus: the planet acts as a natural refinery, baking / dissolving minerals from rocks and redepositing them in other forms; surface appears to be highly enriched in "incompatible elements" (many of which are rare and valuable on Earth) and the planet is highly enriched in deuterium.
Accessibility of resources: Earth: moderate (that which we're used to); Mars: like Earth, but hindered by mobility and the difficulty of removing overburden; Venus: mixed high/low; a large resource base is available to be drawn directly from the atmosphere and which can be distilled/decomposed by simple heating/cooling (for example, 85% H2SO4 -> H2O + O2 + SO2) - the list of known/likely elements in the clouds is very long, even involving significant iron in the form of iron chlorides). However, surface access requires heat-tolerant phase change balloons (the high atmospheric density makes "dredging" with the same fan used for maneuvering a reasonable approach)
Venus is grossly underappreciated as a destination for human settlement, and for exploration in general. Normal Earth air is its own lifting gas. Rather than living in a cramped pressure vessel, colonists would be living in an expansive, bright space perfect for cultivation. Don't like one of your coworkers? Go hang your "room" from a catenary cable on the opposite side of the habita
I can just imagine the Mayan authorities talking with a group of peasants:
Authorities: Hey! You! Why are have you been building this town here? Peasants: Our population grew, we needed to. Many people were working too far away from the old town. Authorities: No no no, this is all wrong. There's no major stars in our constellation at this location. Peasants: But our fields are here. It's good soil, there's water... Authorities: Look, there's a bright star that maps to a position eight kilometers to the east. Go build there. Peasants: You mean, on that barren lava plane on a 45 degree slope? Authorities: Yes, that's the place! Peasants:... why exactly are we doing this, again?
That's exactly the point. It's only about PM. The one type of emission that it's long been known that BEVs don't beat ICEs on. They would also, on the current US grid average, cause more SOx emissions... except for the fact that most SOx-emitting US power plants are already at their sulphur limits, so if they want to sell more power, they have to scrub more. BEVs usually come out slightly ahead on NOx, a moderate improvement on CO2 and trouce ICEs on VOCs and CO. Furthermore, all powertrain-related emissions are moved from "ground level in densely populated areas" to "tops of smokestacks in less densely populated areas", reducing their health effects. It's also worth noting that the grid is getting cleaner, at a surprisingly fast rate, due to the switch from coal to wind + natural gas.
How brake emissions are supposed to work against BEVs is beyond me - because of regenerative braking, BEVs use physical brakes significantly less.
100kW, not W. And if it takes you a few minutes to burn through a couple millimeters of aluminum with a 100kW laser then you're doing something very, very wrong.
That said, yes, you do need high precision focusing and tracking. But it's faster to adjust the aim on a mirror than move an airplane.
Air to air missiles are made of thin aluminum, and high powered lasers are not exactly "a lighted candle". Even if you don't trigger a detonation, you're looking at burning through wiring, damaging control surfaces, damaging guidance systems, and a whole host of other things.
That said, some of the obvious uses are pretty low-hanging fruit, such as detonating incoming missiles or burning through aircraft aluminum. Things like taking out tanks with airborne lasers are obviously completely impractical with current technology (though there may be some weak points, such as tank optical systems and such).
Fairly compact, high power lasers are a reality - they've been doing this with chemical lasers for a while (they're basically fancy rocket engines that generate a lasing plasma exhaust). The problem is, it's easy to keep your planes stocked on jet fuel - nitrogen trifluoride and deuterium, not so much.
Except nowadays everyone simply refers to the concept as "circular reasoning". Which is a much easier to parse, grammatically, than the phrase "begging the question".
There is one "official meaning", and it's largely obsolete. And it was based on a mistranslation anyway, and is linguistically incorrect with modern meanings of the words "beg" and "question".
I would not agree with that. There's a lot of interesting approaches out there (I even have one of my own... though so does every other rocketry nut on the planet;) ) for significant cost reduction. The question is what will actually play out best, with what sort of investment, in what sort of market.
There is more than just refurbishment cost. SpaceX has very large fixed costs. Only the operational costs will be changed by recovery.
Indeed. Recovery can thus be seen as a "scale up" of operations, not a replacement for them. Last I heard they were hoping to get a couple dozen uses out of each stage. Doing so would thus represent a 1 1/2 orders of magnitude scaleup in operations.
It's not really crazy because their needs are certainly expected to increase. Not even taking into account the growth in the market that would occur from such low prices. Every Falcon Heavy is going to consume 28 engines and represents four large cores. And who says things stop with the Heavy? We know some of the speculation about the "Raptor", but they could very well give a Raptor-powered main stage standard Falcon-style boosters. That is, if they ever do end up producing a large Raptor-powered launch system. And no matter what, every Falcon 9 and Falcon Heavy launch consumes one engine that never comes back.
With how much of the launch market they want to take over, especially for heavy launches, they're going to need a serious scaleup. And recovery is a type of "scaleup".
Indeed, I have to wonder what ULA is thinking going forward. They made the mistake of seriously underestimating SpaceX. It's understandable - there have been a lot of wannabee private rocket companies over the years. But they really dropped the ball on this one. Now they're deep in the middle of working towards an incremental, 50% price reduction via the Vulcan, which isn't anywhere close to being enough to be competitive.
So what do they do? I assume they finish their current efforts and try to get as many (probably at least partially coerced) launches out of it as they can. But meanwhile? Some possibilities:
1) Start over from scratch and target an even lower launch cost than SpaceX. It's certainly possible; rocketry costs are still orders of magnitude more than the cost of the energy that the rockets consume. 2) Move to a launch niche market filling in the gaps in SpaceX's product line (smaller rockets, storeable rockets, etc) 3) Take a "bold leap" in another direction, such as focusing on space tugs (such as Lockheed's "Jupiter") - basically, giving SpaceX LEO while claiming for themselves beyond-LEO. 4) Refocus away from rockets, to satellite development 5) Focus on NASA contracts unrelated to delivering payloads for low prices - for example trying to become a prime contractor on interplanetary crew vehicles, whatever-giant-rocket-congress-has-mandated, etc, things of that nature. 6) Move into a rocketry supporting role, focused on launch/range/communications services/etc 7) Try to crush SpaceX by whatever dubious legal and political means they can dream up 8) Put head in sand, pray that SpaceX shoots itself in the foot 9) Give up on the space market altogether, focus on other businesses.
Right now they seem to be going for 20% #7, 80% #8, meaning that they're probably headed toward #9.
I don't think anyone should be surprised that so many in the US access it. So, the top users are from "Iran, China, India, Russia, and the United States"? I think XKCD had something to say about that...
Then again, there are lots of possibilities everywhere. Including far more accessible locations in our own solar system;) For example, we have Enceladus literally jetting out the contents of its ocean into space, just waiting to be collected - an ocean that models show is caused by rock serpentinization, meaning that it's being fed with minerals and hydrogen gas.
I'm personally most curious about Titan (mainly for LNAWKI, though possibly LAWKI in the subsurface water layer). The complexity of the organic chemistry is amazing, and the "missing ethylene and acetylene / probably missing hydrogen / excess methane" problem is very interesting to say the least. Unless you have an idea of some sort of inorganic catalyst that could catalyze the decomposition of longer chain hydrocarbons with hydrogen at cryogenic temperatures! The fact that they've now shown that Ligeia Mare is almost pure methane, rather than accumulated ethane and longer-chain hydrocarbons like they assumed, just makes it all the more interesting. The ethane is going somewhere. (the boring answer would of course be "into the moon", but that still raises questions)
If I was on a hunt for life, I'd start at Saturn. My dream mission would be:
1) RTG-powered ion tug hauls a RTG-powered Titan aerial explorer and its attached ascent stage to Titan. 2) Tug drops the explorer and attached ascent stage and stays in orbit, moving through Titan's exosphere, where it scoops gases for return (I've done the math, the thrust from the ion engine is well greater than the drag; also, most ion engines are very propellant-flexible). 3) During the months while the tug is refilling, the explorer explores Titan (leaving its ascent stage behind on the surface) and collects samples from all over the moon - flying until its flight batteries are exhausted, landing (VTOL), collecting samples and transmitting data while the flight batteries recharge, then taking off again. The tug acts as its data relay. 4) When both the explorer and tug are ready, the explorer returns to its ascent stage and re-ascends, then ditches the spent ascent stage. The tug takes care of maneuvering for re-docking so that the explorer (with its samples, minus any unneeded mass that it left behind) doesn't have to have an OMS. 5) Re-docked, the tug makes a flyby of Enceladus with a carbon aerogel collector open. Additional optional collection flybies include the various rings (aerogel) and Saturn's exosphere (scoop). The scoop acts as a shield during flybies, the same way antennas are often used. 6) The craft returns to Earth orbit. In addition to the collected samples, any gas from Titan's exosphere left in the tanks is itself a sample return.
Yeah, that'd be a flagship mission and would require a couple tech demonstrators beforehand to advance the TRL. But... hopefully some day.
Indeed, it's impossible with current technology to know. And the IAU explicitly rules out extrasolar planets as being planets in their definition of a planet. Which is made all the more humorous by the fact that they have an extrasolar planets working group;)
Bonus points for inconsistency that "dwarf planets" aren't planets but "dwarf stars" are stars.
Brown dwarf, not white. They're not stellar remnants (white dwarfs), they're minimal stars. So minimal, in fact, that unlike red dwarfs they don't even burn 1H, they only burn deuterium.
That said, last I read there's one problem with dwarfs and life: at least with red dwarfs, the habitable zone is so close to the star that the radiation levels at the surface would be hazardous. Which would mean that LAWKI would need to be underground or underwater. Not a huge imposition, but still of relevance.
You're talking about a nuclear project in a country with lots of regulations
What country doesn't? What country shouldn't?
NIMBYs
Demonstrate that NIMBYs are responsible for any relevant portion of this price tag.
fails to mention that the $35bn figure was actually estimated by the wonderfully unbiased Greenpeace
Quick, there's another messenger, shoot them too! Even the government's optimistic estimate is $25B.
who included compound interest on a loan in the figures.
Yes, because here in the real world there is a time value to money. All large construction projects have to amortize their capital costs; it would be grossly incorrect if they weren't doing so.
$8.125bn per megawatt
A figure that you arrive at using silly numbers, but even if we assume that it's right, that's a ridiculous price for a power plant. Fossil fuel power plants are generally $1-2/W (although operations costs are generally a couple times higher due to the cost of buying the fuel), with capacity factors nearly as high as nuclear. Large wind turbines are about $2/W with a capacity factor of ~35% onshore / 40% offshore. Large-scale solar is in the rough ballpark of $2/W installed, with capacity factors usually ranging from ~15% to 30% depending on the technology without thermal storage**. Large hydro is about $1/W with very high availability and rapidly adjustable output. And on and on.
** - You mention Crescent Dunes. It's the first utility-scale solar thermal storage plant, designed to gather data that would be useful in designing larger, more cost effective thermal storage plants. Treating that as the representative for the costs of solar is pretty silly; most solar plants are well cheaper. And solar is in turn one of the more expensive renewables technologies to boot, beaten handily by wind (which is in turn beaten handily by hydro). Nobody is arguing that the future of the planet should be built around mass deployment of the Crescent Dunes plant. But there are lots of people here arguing for making the planet's future with EPRs and similar.
If use-cases vary, then they should have the product designed with selectable modes for the different use cases. And the ability to remember a user's selection.
Slashdot Mirror
They're not available right now, they just started a 1e-24 week strike.
Note: my apologies for Slashdot eating the degree signs and exponents in the above post :P
Also note that if you were to concentrate Martian air to 1ATM and simply add oxygen to reach an Earthlike O2 partial pressure, it would be highly toxic. 1% CO2 causes drowsiness, while 7-10% is lethal. Also, Mars's atmosphere is 0.0557% carbon monoxide, which while not acutely lethal is well above the toxicity limit where acute symptoms and irreversible, accumulative neurological damage occurs.
Venus is far better than Mars. Specifically, Venus's cloudtops - say, 54km altitude, 70 latitude (poleward might be even better, but you start facing more risk from the polar vortices, so we'll just compare 70). Earth by comparison will be equatorial, and Mars will be surface-average.
Gravity (earth relative): Earth: 1.0; Mars: 0.38; Venus: 0.9
Air pressure (atm): Earth: 1.0; Mars: 0.006; Venus: 0.5
Temperature (avg, C): Earth: 26; Mars: -30; Venus: 31
Daily variation (C): Earth: 4-30; Mars: 90; Venus: 15
Day length: Earth: 24; Mars: 24.5; Venus: 48
Ability to relocate / explore new terrain: Earth: moderate; Mars: poor; Venus: high
Overhead radiation shielding mass (meters H2O equivalent): Earth: 10,3; Mars: 0.36; Venus: 5.2
Magnetic field: Earth: 25-65uT, intrinsic; Mars: induced, 20-40nT MPR, 5-20nt magnetosheath; Venus: induced, 40-80 nT MPR, 10-40nT magnetosheath
Health hazards: Earth: those humans evolved to; Mars: 1) Fine, abrasive electrostatic dust, 2) silicosis; 3) perchlorates; 4) hexavalent chromium; 5) other chemical hazards; Venus: 1) Corrosive acid mists; 2) hydrogen fluoride; 3) probably others of relevance
Other local hazards: Earth: those humans evolved to; Mars: marsquakes, landslides, dust storms, probably others. Venus: poorly understood - lightning (although we don't know at what altitude), gusts/shear (probably Earthlike, but poorly quantified), icing (probably not, but maybe), possibly others. Needs more study, but Mars gets the lion's share of the planetary exploration budget and everything else competes for the scraps.
Delta-V to habitable area from LEO (km/s, aerocapture assumed): Earth: 0; Mars: 4.7; Venus: 4.2
Delta-V from habitable area to LEO (km/s, aerocapture assumed): Earth: 9.8; Mars: 10.0; Venus: 15.5
Transit time (months): Earth: 0; Mars: 9; Venus: 5
Launch window frequency (months): Earth: 0; Mars: 25; Venus: 19
Landing difficulty: Earth: moderate (dense atmosphere, oceans to land in, compacting soil, readily available rescue); Mars: hard (reversed conditions of Earth): Venus: easy (no landing at all; your landing ellipse is "a large chunk of the planet")
Solar energy (29% triple-junction W/m): Earth: 290; Mars: 45; sometimes almost none; Venus: 400
Capturable wind energy: Earth: moderate; Mars: effectively none; Venus: high
Diversity / value of resources: Earth: moderate (that which we're used to); Mars: probably less than Earth, but not "poor"; Venus: the planet acts as a natural refinery, baking / dissolving minerals from rocks and redepositing them in other forms; surface appears to be highly enriched in "incompatible elements" (many of which are rare and valuable on Earth) and the planet is highly enriched in deuterium.
Accessibility of resources: Earth: moderate (that which we're used to); Mars: like Earth, but hindered by mobility and the difficulty of removing overburden; Venus: mixed high/low; a large resource base is available to be drawn directly from the atmosphere and which can be distilled /decomposed by simple heating/cooling (for example, 85% H2SO4 -> H2O + O2 + SO2) - the list of known/likely elements in the clouds is very long, even involving significant iron in the form of iron chlorides). However, surface access requires heat-tolerant phase change balloons (the high atmospheric density makes "dredging" with the same fan used for maneuvering a reasonable approach)
Venus is grossly underappreciated as a destination for human settlement, and for exploration in general. Normal Earth air is its own lifting gas. Rather than living in a cramped pressure vessel, colonists would be living in an expansive, bright space perfect for cultivation. Don't like one of your coworkers? Go hang your "room" from a catenary cable on the opposite side of the habita
I can just imagine the Mayan authorities talking with a group of peasants:
Authorities: Hey! You! Why are have you been building this town here? ... why exactly are we doing this, again?
Peasants: Our population grew, we needed to. Many people were working too far away from the old town.
Authorities: No no no, this is all wrong. There's no major stars in our constellation at this location.
Peasants: But our fields are here. It's good soil, there's water...
Authorities: Look, there's a bright star that maps to a position eight kilometers to the east. Go build there.
Peasants: You mean, on that barren lava plane on a 45 degree slope?
Authorities: Yes, that's the place!
Peasants:
Indeed. It's clearly not a Mayan city. It's a giant carving of the full text of the Wikipedia article on Pareidolia.
That's exactly the point. It's only about PM. The one type of emission that it's long been known that BEVs don't beat ICEs on. They would also, on the current US grid average, cause more SOx emissions... except for the fact that most SOx-emitting US power plants are already at their sulphur limits, so if they want to sell more power, they have to scrub more. BEVs usually come out slightly ahead on NOx, a moderate improvement on CO2 and trouce ICEs on VOCs and CO. Furthermore, all powertrain-related emissions are moved from "ground level in densely populated areas" to "tops of smokestacks in less densely populated areas", reducing their health effects. It's also worth noting that the grid is getting cleaner, at a surprisingly fast rate, due to the switch from coal to wind + natural gas.
How brake emissions are supposed to work against BEVs is beyond me - because of regenerative braking, BEVs use physical brakes significantly less.
100kW, not W. And if it takes you a few minutes to burn through a couple millimeters of aluminum with a 100kW laser then you're doing something very, very wrong.
That said, yes, you do need high precision focusing and tracking. But it's faster to adjust the aim on a mirror than move an airplane.
Air to air missiles are made of thin aluminum, and high powered lasers are not exactly "a lighted candle". Even if you don't trigger a detonation, you're looking at burning through wiring, damaging control surfaces, damaging guidance systems, and a whole host of other things.
Missiles are not built like tanks.
Deliberately-blinding weapons are illegal.
That said, some of the obvious uses are pretty low-hanging fruit, such as detonating incoming missiles or burning through aircraft aluminum. Things like taking out tanks with airborne lasers are obviously completely impractical with current technology (though there may be some weak points, such as tank optical systems and such).
Fairly compact, high power lasers are a reality - they've been doing this with chemical lasers for a while (they're basically fancy rocket engines that generate a lasing plasma exhaust). The problem is, it's easy to keep your planes stocked on jet fuel - nitrogen trifluoride and deuterium, not so much.
So, you're saying that Zug deserves our praise? That we should kneel before Zug?
Except nowadays everyone simply refers to the concept as "circular reasoning". Which is a much easier to parse, grammatically, than the phrase "begging the question".
There is one "official meaning", and it's largely obsolete. And it was based on a mistranslation anyway, and is linguistically incorrect with modern meanings of the words "beg" and "question".
I would not agree with that. There's a lot of interesting approaches out there (I even have one of my own... though so does every other rocketry nut on the planet ;) ) for significant cost reduction. The question is what will actually play out best, with what sort of investment, in what sort of market.
Indeed. Recovery can thus be seen as a "scale up" of operations, not a replacement for them. Last I heard they were hoping to get a couple dozen uses out of each stage. Doing so would thus represent a 1 1/2 orders of magnitude scaleup in operations.
It's not really crazy because their needs are certainly expected to increase. Not even taking into account the growth in the market that would occur from such low prices. Every Falcon Heavy is going to consume 28 engines and represents four large cores. And who says things stop with the Heavy? We know some of the speculation about the "Raptor", but they could very well give a Raptor-powered main stage standard Falcon-style boosters. That is, if they ever do end up producing a large Raptor-powered launch system. And no matter what, every Falcon 9 and Falcon Heavy launch consumes one engine that never comes back.
With how much of the launch market they want to take over, especially for heavy launches, they're going to need a serious scaleup. And recovery is a type of "scaleup".
Indeed, I have to wonder what ULA is thinking going forward. They made the mistake of seriously underestimating SpaceX. It's understandable - there have been a lot of wannabee private rocket companies over the years. But they really dropped the ball on this one. Now they're deep in the middle of working towards an incremental, 50% price reduction via the Vulcan, which isn't anywhere close to being enough to be competitive.
So what do they do? I assume they finish their current efforts and try to get as many (probably at least partially coerced) launches out of it as they can. But meanwhile? Some possibilities:
1) Start over from scratch and target an even lower launch cost than SpaceX. It's certainly possible; rocketry costs are still orders of magnitude more than the cost of the energy that the rockets consume.
2) Move to a launch niche market filling in the gaps in SpaceX's product line (smaller rockets, storeable rockets, etc)
3) Take a "bold leap" in another direction, such as focusing on space tugs (such as Lockheed's "Jupiter") - basically, giving SpaceX LEO while claiming for themselves beyond-LEO.
4) Refocus away from rockets, to satellite development
5) Focus on NASA contracts unrelated to delivering payloads for low prices - for example trying to become a prime contractor on interplanetary crew vehicles, whatever-giant-rocket-congress-has-mandated, etc, things of that nature.
6) Move into a rocketry supporting role, focused on launch/range/communications services/etc
7) Try to crush SpaceX by whatever dubious legal and political means they can dream up
8) Put head in sand, pray that SpaceX shoots itself in the foot
9) Give up on the space market altogether, focus on other businesses.
Right now they seem to be going for 20% #7, 80% #8, meaning that they're probably headed toward #9.
I don't think anyone should be surprised that so many in the US access it. So, the top users are from "Iran, China, India, Russia, and the United States"? I think XKCD had something to say about that...
TRL = Technology Readiness Level
I wonder if this model applies as well to spallation. I would assume that it would...
There are lots of possibilities, yes.
Then again, there are lots of possibilities everywhere. Including far more accessible locations in our own solar system ;) For example, we have Enceladus literally jetting out the contents of its ocean into space, just waiting to be collected - an ocean that models show is caused by rock serpentinization, meaning that it's being fed with minerals and hydrogen gas.
I'm personally most curious about Titan (mainly for LNAWKI, though possibly LAWKI in the subsurface water layer). The complexity of the organic chemistry is amazing, and the "missing ethylene and acetylene / probably missing hydrogen / excess methane" problem is very interesting to say the least. Unless you have an idea of some sort of inorganic catalyst that could catalyze the decomposition of longer chain hydrocarbons with hydrogen at cryogenic temperatures! The fact that they've now shown that Ligeia Mare is almost pure methane, rather than accumulated ethane and longer-chain hydrocarbons like they assumed, just makes it all the more interesting. The ethane is going somewhere. (the boring answer would of course be "into the moon", but that still raises questions)
If I was on a hunt for life, I'd start at Saturn. My dream mission would be:
1) RTG-powered ion tug hauls a RTG-powered Titan aerial explorer and its attached ascent stage to Titan.
2) Tug drops the explorer and attached ascent stage and stays in orbit, moving through Titan's exosphere, where it scoops gases for return (I've done the math, the thrust from the ion engine is well greater than the drag; also, most ion engines are very propellant-flexible).
3) During the months while the tug is refilling, the explorer explores Titan (leaving its ascent stage behind on the surface) and collects samples from all over the moon - flying until its flight batteries are exhausted, landing (VTOL), collecting samples and transmitting data while the flight batteries recharge, then taking off again. The tug acts as its data relay.
4) When both the explorer and tug are ready, the explorer returns to its ascent stage and re-ascends, then ditches the spent ascent stage. The tug takes care of maneuvering for re-docking so that the explorer (with its samples, minus any unneeded mass that it left behind) doesn't have to have an OMS.
5) Re-docked, the tug makes a flyby of Enceladus with a carbon aerogel collector open. Additional optional collection flybies include the various rings (aerogel) and Saturn's exosphere (scoop). The scoop acts as a shield during flybies, the same way antennas are often used.
6) The craft returns to Earth orbit. In addition to the collected samples, any gas from Titan's exosphere left in the tanks is itself a sample return.
Yeah, that'd be a flagship mission and would require a couple tech demonstrators beforehand to advance the TRL. But... hopefully some day.
Indeed, it's impossible with current technology to know. And the IAU explicitly rules out extrasolar planets as being planets in their definition of a planet. Which is made all the more humorous by the fact that they have an extrasolar planets working group ;)
Bonus points for inconsistency that "dwarf planets" aren't planets but "dwarf stars" are stars.
The IAU is such a joke.
Brown dwarf, not white. They're not stellar remnants (white dwarfs), they're minimal stars. So minimal, in fact, that unlike red dwarfs they don't even burn 1H, they only burn deuterium.
That said, last I read there's one problem with dwarfs and life: at least with red dwarfs, the habitable zone is so close to the star that the radiation levels at the surface would be hazardous. Which would mean that LAWKI would need to be underground or underwater. Not a huge imposition, but still of relevance.
What country doesn't? What country shouldn't?
Demonstrate that NIMBYs are responsible for any relevant portion of this price tag.
Quick, there's another messenger, shoot them too!
Even the government's optimistic estimate is $25B.
Yes, because here in the real world there is a time value to money. All large construction projects have to amortize their capital costs; it would be grossly incorrect if they weren't doing so.
A figure that you arrive at using silly numbers, but even if we assume that it's right, that's a ridiculous price for a power plant. Fossil fuel power plants are generally $1-2/W (although operations costs are generally a couple times higher due to the cost of buying the fuel), with capacity factors nearly as high as nuclear. Large wind turbines are about $2/W with a capacity factor of ~35% onshore / 40% offshore. Large-scale solar is in the rough ballpark of $2/W installed, with capacity factors usually ranging from ~15% to 30% depending on the technology without thermal storage**. Large hydro is about $1/W with very high availability and rapidly adjustable output. And on and on.
** - You mention Crescent Dunes. It's the first utility-scale solar thermal storage plant, designed to gather data that would be useful in designing larger, more cost effective thermal storage plants. Treating that as the representative for the costs of solar is pretty silly; most solar plants are well cheaper. And solar is in turn one of the more expensive renewables technologies to boot, beaten handily by wind (which is in turn beaten handily by hydro). Nobody is arguing that the future of the planet should be built around mass deployment of the Crescent Dunes plant. But there are lots of people here arguing for making the planet's future with EPRs and similar.
So, what you're saying is, what you want is a reactor more modern than the most modern reactor under construction?
You know, you could just ask for fusion plants while you're at it.
If use-cases vary, then they should have the product designed with selectable modes for the different use cases. And the ability to remember a user's selection.