Posted on 12/07/2022 12:11:15 AM PST by Jonty30
The day may be coming when we can bring asteroids back to earth to process. I understand the usefulness of the metals in these asteroids and I understand the benefits of grinding them to a powder to get the water and gases released from them.
My question are there any uses for the rock that will be left over?
Bringing it to Earth is out of the question. Orbital perturbation is a thing, and the larger the mass we bring in to orbit our planet, the more likely we are to screw up things on Earth.
Three Gorges Dam in China, for instance, has been shown to have impacted the rotation of our planet. Think about that.
Not using any propulsion system currently under serious consideration.
The closest you could get to that is by loading inert wastes into a cart which is then accelerated by an electromagnetic rail gun (of course, the cart has to then be decelerated if you don't want to lose it forever - maybe you could regain some of the spent energy there).
Reaction-mass propulsion is so... yesterday.
Regards,
There are different types of asteroids, no point in bringing back a bunch of “dirty snow,” etc.
But an asteroid that is made of mostly nickel, for example, would be extremely valuable.
Interesting that this subject has come up. I just finished reading the novel “Delta V”:https://daniel-suarez.com/Delta-v_synopsis.html
If a big rock were to drop on Davos next time the fascists meet, that would be helpful.
What about the energy needed to propel it from the surface of the Earth to orbit? That’s called escape velocity. Escape velocity is the speed at which an object must travel to break free of a planet or moon’s gravitational force and enter orbit. A spacecraft leaving the surface of Earth, for example, needs to be going about 11 kilometers (7 miles) per second, or over 40,000 kilometers per hour (25,000 miles per hour), to enter orbit.
That’s the real cost, because the Earth is in a very deep gravity well.
Quote: https://www.nasa.gov/audience/foreducators/k-4/features/F_Escape_Velocity.html
Achieving escape velocity is one of the biggest challenges facing space travel. The vehicle requires an enormous amount of fuel to break through Earth’s gravitational pull. All that fuel adds significant weight to the spacecraft, and when an object is heavier, it takes more thrust to lift it. To create more thrust, you need more fuel. It’s a cycle that scientists are hoping to resolve by creating lighter vehicles, more efficient fuels and new methods of propulsion that don’t require the same ingredients to attain great speeds.
There are plenty of high value metals in asteroids.
But instead of dragging the back to earth, set up a space-furmace and break them down out thete
Sure, if it's big enough, and falls on DC...
Kinda tough to answer... Do we need them? No... Do we benefit from them? No... Are they educational for us? Yes. But the bottom line is the cost of the endeavor... Just how much material would need to come out of a rock you have to go to outer space to get?? And then how the hell do you get it back to earth without causing a new iceage!!??
Nope
Notably, with radiation of especially great concern outside of earth orbit and on the lunar surface, much of the raw material of asteroids could get processed into composite building materials that act as radiation shielding.
As it happens, some of the ambient radiation in space and on the lunar surface comes from high energy neutrons in the solar wind that generate dangerous radioactive daughter particles when they contact spacecraft or the lunar surface. Slabs of metal foam sandwiched between panels of compressed and vitrified rock particles might be a preferred anti-radiation building material. The metal foam would stop the neutrons, while a layer of vitrified particles would sop up the radioactive daughter particles.
Plausibly, an advanced extraction and manufacturing plant in lunar orbit could mine chunks of asteroids, fabricate such products, and then transport them to the lunar surface or space stations for purposes of construction. Even though scientifically plausible, no such technology currently exists, nor is there an economic case yet for developing it. We are decades or a century or more away from any such possibility.
Always happy to join in on a spirited debate concerning Celestial Mechanics!
The simple fact is: Excluding the effect of the atmosphere (and in my original posting in this thread, I explicitly referred to the energy-savings yielded by aerobraking when returning to Earth), the energy required to attain orbit is exactly equal to the energy required to de-orbit.
When visiting multiple celestial bodies, it's also possible to "steal" kinetic energy from intermediate bodies as one flies by, but for a simple one-stop visit involving only two bodies (e.g., departing Earth, flying to an asteroid, collecting samples, and then returning to Earth), the return trip costs just as much energy as the first leg of the journey.
Regards,
Bringing millions of tons of asteroid material to Earth would have a negligible effect on Earth's angular momentum / rotation and orbit around the Sun.
One could rightly refer to other dangers (crash-landings, etc.), but the addition of a paltry hundred million tons of matter to the Earth's surface would entail negligible effects.
The Three Gorges Dam involves significantly MORE mass displacement (literally billions of tons of water were diverted, but it is still nothing to worry about re. Earth's rotation).
Regards,
Anything under the mass of a good-sized asteroid like, say, Eros, would have an insignificant impact on Earth's angular momentum (and no one's talking about bringing down entire asteroids - just some of the processed metals they contain). The effect on the length of Earth's day would have to be measured in fractions of a microsecond.
The displacement of billions of tons of water in any good-sized dam has a greater effect.
Regards,
Solid blocks of vitrified matter would be an extremely good thermal conductor, and thus an extremely bad thermal insulator.
Insulation made from glass fibers and such on Earth works only because of the trapped air.
A vacuum, on the other hand, is a good thermal insulator! Consider the thermos bottle!
And on the Moon, vacuum is plentiful!
Regards,
And that's my fault somehow?
You can stop talking about queue-ah-nahn.
Pay more attention, I only mentioned QTARDS.
Those are our own homegrown nasty rude smug-ass Qtards.
If you want a list, ask Ransomnote. She has lists, oh yes.
It's not my fault they are tards, or Qtards.
I pretty much discourage such retardation.
So should everyone, who needs a bunch of tards running around.
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