Problem is example the exposed ice will sublimate inside of the moon orbit, due to the sunshine.
Means the water/hydrocarbons rest beyond the sun evaporative reach.
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Nomad5891 wrote:I agree Earth has too high gravitanional pull and too thick of an atmosphere that make constant transport up and down to space too complex, costy and dangerous.
Big_Gazza wrote:Nomad5891 wrote:I agree Earth has too high gravitanional pull and too thick of an atmosphere that make constant transport up and down to space too complex, costy and dangerous.
The costs have nothing to do with Earths gravity but simply the deltaV required to move recovered materials from one orbit (ie the asteroid) to where it is needed (eg earth, moon, orbital station).
This is basic physics and isn't going to go away. It doesn't really matter what form the recovered materials take (raw materials, finished products), its only about mass. the greater the mass, the greater the energy requirement and the larger the transportation system needed to move it.
A small, 10 km asteroid contian more gold, platinium, iridium and so on than the top ten km crust of earth.
There are asteroids out there that composed from pure, high quality iron-nickel alloy.
Possible to make/do industrial processes on never seen scale, with very light and simple tools.
Easy job with a pure metal asteroid, and with hair thick solar mirror.
Gather a few asteroids together, start building a scaffolding and production site around them, and use their materials as needed
Then you can simply maneuver the structure to where you want it, avoiding any planet's tidal effects
But I have not seen any
demonstration where Pluto sits in a belt of debris. So to me it looks like games with definitions. One can hardly expect Pluto
to clear out the Kuiper belt.
Titan is a cold moon of Saturn that has liquid hydrocrabons acting as a substitute water cycle.
2) In terms of difficulty, therefor cost it is much easier and less complex to safely land same mass of anything to the Moon than to Earth.
I think we are far from understanding how this universe works, lacking full understanding of mundane phenomenon as gravity, so stating that something is basic physics means very little.
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In the photo, in general, the goal of the spacewalk is visible. These photos are from 2018, when the astronauts had to perform an operation to find an external hole that caused the depressurization of the Soyuz spacecraft. By the way, this was the first operation of this level of complexity on a spaceship in history.Nomad5891 wrote:Great pics Scorpius. Any idea what the EVA was for or just some sort of training?
In the space the distance and energy requirement not the same .GarryB wrote:
There are certainly likely to be asteroids with valuable materials in them, but just as common if not more so are icy comets and rocky rubble piles of little to no value at all.
The energy needed to change the orbit of such objects is very similar to the energy needed to smash them into tiny pieces... not to mention the distances involved.
Construction in orbit is notoriously problematic with tens of thousands of tools lost in space in orbit smashing in to things, because you let go for a second and it just floats away. Once out of reach it is gone forever and a new threat to everything in orbit.
Out at the orbit of these asteroids in the asteroid belt that solar mirror would need to be enormous... at the oort cloud no size would be big enough to be effective... would be like trying to use a solar furnace with moonlight.
But that is the problem... decent sized asteroids are enormous distances apart and the heavy ones would require enormous amounts of energy to shift.
Big_Gazza wrote:limb wrote:Then what kind of new manned spacecraft trips and tech or planetary colonies can we actually expect in the next 50-70 years?
Regarding asteroids, what about mining iridium or beryllium?
What makes it impossible to use some kind of charge neutralizing tech to prevent regolith sticking to surfaces.? Its hard to imagine that preventing dust sticking is more complex than designing HGVs.
We need to identify asteroids that have useful concentrations of the valuable materials for which we have great need. Not sure what that might be however, and i'd suggest that it makes more sense to extract rare materials from oceanic seawater rather than trying to prospect orbiting rocks out past Mars.
IMHO manned space activities will inevitably be driven by the desire to explore (and wave the flag) rather than commercial considerations.
Not sure about how we deal with the dust issue on lunar bases. Rigorous segregation of dirty materials (such as EVA suits) from habitable spaces is probably the main focus. Suits would ideally be designed to include an integral airlock arrangement allowing the occupant to dock to the station and exit the suit without needing to bring the dirty suit in to the station interior. Something like a Russian Orlan suit with its rear hatch but where it engages with an airlock into the station interior.
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kvs wrote:Regarding the claim about easy peasy lemon squeezy space mining post above:
E=1/2 mv^2 is a universal formula outside of the relativistic limit (it then becomes the leading order expansion term).
So mountain size rocks in space take the same energy to move anywhere. The only gain from moving orbiting rocks
is from the gravitational potential well where you let the planet do the work for you. But moving huge objects from
the asteroid belt to the Earth is not that cheap. The gain from the Sun's potential well does not offset the need
for a lot of kinetic energy to slow down the belt objects to orbits close to that of Earth with the subsequent capture
by Earth's gravitational potential well.
None of the sci-fi fantasy has these mountains dumped to the Earth from orbit. They always show mining transport
spaceships (and the xenomorphs that infest them).
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There are 3600 known asteroid closer than the surface of Moon.
Oceanic seawater has no iridium, beryllium, gallium, and indium of note. How many decades are we away from seawater filtering. Is it really that much more profitable, with all the additional R&D, massive infrastructure, etc to accumulate enough precious metals of note?
Why not use electrostaic charge or some kind of acid wash to remove regolith
The lack of interest in space exploration is one of the main reasons I despise capitalism and would prefer a centrally planned economy.
None of the sci-fi fantasy has these mountains dumped to the Earth from orbit. They always show mining transport
spaceships (and the xenomorphs that infest them).
kvs wrote:Regarding the claim about easy peasy lemon squeezy space mining post above:
E=1/2 mv^2 is a universal formula outside of the relativistic limit (it then becomes the leading order expansion term).
So mountain size rocks in space take the same energy to move anywhere. The only gain from moving orbiting rocks
is from the gravitational potential well where you let the planet do the work for you. But moving huge objects from
the asteroid belt to the Earth is not that cheap. The gain from the Sun's potential well does not offset the need
for a lot of kinetic energy to slow down the belt objects to orbits close to that of Earth with the subsequent capture
by Earth's gravitational potential well.
None of the sci-fi fantasy has these mountains dumped to the Earth from orbit. They always show mining transport
spaceships (and the xenomorphs that infest them).
Nomad5891 wrote:kvs wrote:Regarding the claim about easy peasy lemon squeezy space mining post above:
E=1/2 mv^2 is a universal formula outside of the relativistic limit (it then becomes the leading order expansion term).
So mountain size rocks in space take the same energy to move anywhere. The only gain from moving orbiting rocks
is from the gravitational potential well where you let the planet do the work for you. But moving huge objects from
the asteroid belt to the Earth is not that cheap. The gain from the Sun's potential well does not offset the need
for a lot of kinetic energy to slow down the belt objects to orbits close to that of Earth with the subsequent capture
by Earth's gravitational potential well.
None of the sci-fi fantasy has these mountains dumped to the Earth from orbit. They always show mining transport
spaceships (and the xenomorphs that infest them).
But why would you want to move asteroids to Earth's orbit?
It is not like we would be sending actual miners in space suits with space picks to hammer the rock so they need to have the asteroid close by...
Mining, refering to extracting needed materials from asteroids can be done without need to change its trajectory...bots can mine it autonomously while it moves on its trajectory.
Here on Earth we are not like moving mountains of ore either- we just build a processing plant nearby.
Then you just transport the refined materials where they are needed. And you dont need to transport them at once- it can be done little by little but at higher rate.
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flamming_python wrote:Bringing asteroids down to Earth for mining would be insane
These are things that weigh hundreds of millions of tons. We can barely land 1-2 ton re-entry vehicles and those are far more aerodynamic and controllable
It should be possible to smash them into the moon. When we have mining facilities on the moon and space elevators to it from Earth, that might make sense.
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kvs wrote:
Gravity is not the only thing to consider for a space elevator. Even if magic can happen and it can be designed to
stay up without tearing itself apart and resonating to hell, the amount of wobble it will need to have is going
to make all elevator rides vomit joy rides.
flamming_python wrote:Bringing asteroids down to Earth for mining would be insane
These are things that weigh hundreds of millions of tons. We can barely land 1-2 ton re-entry vehicles and those are far more aerodynamic and controllable
It should be possible to smash them into the moon. When we have mining facilities on the moon and space elevators to it from Earth, that might make sense. Of course though the Moon has already accumulated millions of asteroid impacts. Likely, you'd be able to find a lot of interesting stuff there already.
But other than that, you'd want to mine them in space, and ideally build things right there in space too. I guess smashing processed mineral or metal slabs into the Earth is an option but for all that effort, why not just mine that same thing from the Earth's crust? Within the next few decades mining from the seafloor or ocean floors should be viable, and there are many deposits there, and the cost of land-based mines that go deeper into the Earth's crust should decrease too.
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kvs wrote:Those magic carbon nanotubes will make space elevators a reality any day now. I just know it my heart. /sarc.
I always find it funny how space elevator fantasy completely forgets about the atmosphere. Even if the air density
falls off exponentially with height (e-folding rate of about 7 km), it will still impart a lot of force on this fixed obstacle.
In fact, the integrated exposure to air flow forces of any space elevator is huge compared to any structure built
by humans. Skyscrapers (e.g. Burj Khalifa) and other supertall structures (CN Tower) are designed to bend like
reeds to wind action. So any space elevator will have to be designed to deform in different directions at different
heights (the atmosphere does not flow in the same direction through its whole column at any given position on
the surface, winds reverse direction for various reasons).
Just imagine the resonance failure potential of such a structure. Its very length will be a critical weakness since
it can develop all sorts of bending harmonics and 3D ones at that. The Tacoma Narrows bridge was brought
down by experiencing a resonance with Kelvin-Helmoltz instability rolls hitting it at the right frequency. With
a space elevator even think layers of the atmosphere will exert enormous torques on it when integrated over
kilometers of length.
Gravity is not the only thing to consider for a space elevator. Even if magic can happen and it can be designed to
stay up without tearing itself apart and resonating to hell, the amount of wobble it will need to have is going
to make all elevator rides vomit joy rides.
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kvs wrote:Electromagnetic ramps I think deserve more attention than space elevators. They could give rocket planes a substantial boost even
with all the lower atmosphere drag. They cannot be built too high, but can be stretched out horizontally. Imagine accelerating
for 10 km on a curved ramp that concentrates the curvature near the end. Of course there will be energy lost to drag and any
ship that uses such a ramp will have to have ceramic tiles or panels. But actual calculations need to be done and I have not
seen any (maybe I have not looked hard enough).
As for the environmental impact of a space elevator. It will be a giant short circuit in the global electric current. Going through
the ionosphere will create an opportunity for the electrical ground (electron pool) to connect to the positive charges created
on an ongoing basis by hard UV and solar wind associated proton and electron fluxes. Every CME event will produce wonders
of surging electricity from the ground to counter the solar proton precipitation which is not as confined to the auroral belt
and penetrates deeper into the atmosphere.
The global electric circuit is not well studied and its effect on health is ignored. People attribute weather impacts on people's
well being (a real and documented thing) to pressure variations. But some of the effect may be due to changes in the ambient
low level current flow.
Also, if wind mills mess up birds due to infrasound, the space elevator will be producing enormous infrasound emissions with
wavelengths long enough to pollute thousands of kilometers away.
The space elevator idea should be compared to the Tower of Babel.
kvs wrote:Electromagnetic ramps I think deserve more attention than space elevators. They could give rocket planes a substantial boost even
with all the lower atmosphere drag. They cannot be built too high, but can be stretched out horizontally. Imagine accelerating
for 10 km on a curved ramp that concentrates the curvature near the end. Of course there will be energy lost to drag and any
ship that uses such a ramp will have to have ceramic tiles or panels. But actual calculations need to be done and I have not
seen any (maybe I have not looked hard enough).
As for the environmental impact of a space elevator. It will be a giant short circuit in the global electric current. Going through
the ionosphere will create an opportunity for the electrical ground (electron pool) to connect to the positive charges created
on an ongoing basis by hard UV and solar wind associated proton and electron fluxes. Every CME event will produce wonders
of surging electricity from the ground to counter the solar proton precipitation which is not as confined to the auroral belt
and penetrates deeper into the atmosphere.
The global electric circuit is not well studied and its effect on health is ignored. People attribute weather impacts on people's
well being (a real and documented thing) to pressure variations. But some of the effect may be due to changes in the ambient
low level current flow.
Also, if wind mills mess up birds due to infrasound, the space elevator will be producing enormous infrasound emissions with
wavelengths long enough to pollute thousands of kilometers away.
The space elevator idea should be compared to the Tower of Babel.
Daniel_Admassu wrote:kvs wrote:Electromagnetic ramps I think deserve more attention than space elevators. They could give rocket planes a substantial boost even
with all the lower atmosphere drag. They cannot be built too high, but can be stretched out horizontally. Imagine accelerating
for 10 km on a curved ramp that concentrates the curvature near the end. Of course there will be energy lost to drag and any
ship that uses such a ramp will have to have ceramic tiles or panels. But actual calculations need to be done and I have not
seen any (maybe I have not looked hard enough).
As for the environmental impact of a space elevator. It will be a giant short circuit in the global electric current. Going through
the ionosphere will create an opportunity for the electrical ground (electron pool) to connect to the positive charges created
on an ongoing basis by hard UV and solar wind associated proton and electron fluxes. Every CME event will produce wonders
of surging electricity from the ground to counter the solar proton precipitation which is not as confined to the auroral belt
and penetrates deeper into the atmosphere.
The global electric circuit is not well studied and its effect on health is ignored. People attribute weather impacts on people's
well being (a real and documented thing) to pressure variations. But some of the effect may be due to changes in the ambient
low level current flow.
Also, if wind mills mess up birds due to infrasound, the space elevator will be producing enormous infrasound emissions with
wavelengths long enough to pollute thousands of kilometers away.
The space elevator idea should be compared to the Tower of Babel.
EM Catapults also have their share of problems. Since the spacecraft is unpowered and would depend on the ramp for imparting energy, the ship will have to attain the projectile escape velocity, which for earth is around 40,000 km/hr. This will mean two things:
1. With a given practical stretch of ramp it should have a very high acceleration, which, after some threshold value will mean unsuitable for crewed missions.
2. It has a limit to the acceleration attainable and hence to reach escape velocity it will need a longer ramp which could be impractical.
I am too lazy to do the calculations but I guess the solutions will involve staggering quantities for EM ramps as well.
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