Daunting space mission: Send astronauts to asteroid

[Quantum Windbag]

Uh, not every asteroid is a "gold mine".

Once they hit the moon, they are "dust".

Using the science of "spectroscopy", scientists can tell the composition of asteroids and know in advance "which ones to visit".

Spectroscopy is used in physical and analytical chemistry because atoms and molecules have unique spectra. These spectra can be interpreted to derive information about the atoms and molecules, and they can also be used to detect, identify and quantify chemicals. Spectroscopy is also used in astronomy and remote sensing. Most research telescopes have spectrographs. The measured spectra are used to determine the chemical composition and physical properties of astronomical objects (such as their temperature and velocity).

Moon - Wikipedia, the free encyclopedia

Now, the question you should ask is, "How many of those rocks came from asteroids"?

Do you have any idea how spectroscopy works?

You really should catch up with the actual science about the moon.

SELENOLOGY TODAY

Ok, I was wrong about, uh, what? Explain it to me in your own words.

Everything.

 

[Quantum Windbag]

Or reel things in. An asteroid of even a mile across has virtually no gravity. You couldn't really "land". You would simply "bounce". Hence, the "tether". To reel your ship to the asteroid.

Why would you want to reel your ship to an asteroid? It would be spinning on three axis in a way that would make it extremely dangerous to get close to it, and anchoring your ship to it with a tether would cause your ship to trade momentum and force you to use irreplaceable fuel to reduce all that extraneous motion.

Because not all asteroids are spinning "fast"?

Or because an object miles across doesn't spin so fast you couldn't match your ship to it?

Or because with newly developed technology (think force absorbing tethers), you wouldn't use that much fuel?

Or because using fuel based on hydrogen and oxygen (water), it wouldn't matter how much you used?

Or because, well, never-mind. You wouldn't understand.

It doesn't matter whether they spin fast or slow, you have to match the spin exactly before you can put a tether on one.

If I understand your position correctly, the larger something is, the slower it spins. Please note that I completely disagree with that position, but I want to be sure I understand your position.

The Earth is about 25,000 miles in circumference, and spins on its axis in 24 hours. That means that the speed of rotation at the surface is over 1000 mph. If, as you assert, larger objects spin slower, that would mean that asteroids spin much faster than the Earth, and they would spin faster than 1000 mph.

FYI, most asteroids do spin faster than once every 24 hours. I will let you work out the actual surface velocity of a 100 meter asteroid which revolves in about 2 hours.

 

[Quantum Windbag]

Why the Moon

Like the "fusion" reactor and the "there could be ten billion tons of water" blah blah blah.

It's more "hope" than "guess".

Earth's oceans came from the asteroids. That has to be true.

That link did not say the Earth's oceans came from the asteroids but instead comets.

A well known theory generally accepted in the astromomy community says that not all, but a large share of the water in our oceans came from comets impacting earth.

You seem to be wilfully ignorant and that kind of ignorance as in your case as an engineer usually comes from political dogmatism.

Officially, according to NASA guidelines, a comet has to be at least 85% ice in order to be considered an actual comet.

Comet - Wikipedia, the free encyclopedia

So what are they called if only 84% ice?

Asteroids.

 

[rdean]

Why would you want to reel your ship to an asteroid? It would be spinning on three axis in a way that would make it extremely dangerous to get close to it, and anchoring your ship to it with a tether would cause your ship to trade momentum and force you to use irreplaceable fuel to reduce all that extraneous motion.

Because not all asteroids are spinning "fast"?

Or because an object miles across doesn't spin so fast you couldn't match your ship to it?

Or because with newly developed technology (think force absorbing tethers), you wouldn't use that much fuel?

Or because using fuel based on hydrogen and oxygen (water), it wouldn't matter how much you used?

Or because, well, never-mind. You wouldn't understand.

It doesn't matter whether they spin fast or slow, you have to match the spin exactly before you can put a tether on one.

If I understand your position correctly, the larger something is, the slower it spins. Please note that I completely disagree with that position, but I want to be sure I understand your position.

The Earth is about 25,000 miles in circumference, and spins on its axis in 24 hours. That means that the speed of rotation at the surface is over 1000 mph. If, as you assert, larger objects spin slower, that would mean that asteroids spin much faster than the Earth, and they would spin faster than 1000 mph.

FYI, most asteroids do spin faster than once every 24 hours. I will let you work out the actual surface velocity of a 100 meter asteroid which revolves in about 2 hours.

Don't worry, no one is going to fly a ship that only goes 1,000 mph or try to land on an asteroid that's only 100 meters across.

 

[rdean]

You know what's hilarious is when an object is spinning and you land on it. Imagine the center of a "merry go round". You can sit in the exact center and feel no "pull". It would be the same with an asteroid. When it rotates, the axis is relatively slow. That's where you would land. Did that really have to be explained? I was waiting, but no one figured it out. Sad.

 

[daveman]

Ceramics are used to make heat shielding, not to mention ceramic armor plating for hummers and and other vehicles to protect troops from IEDs. Having an abundant source of raw materials for ceramics on the moon is one of the things that make going there a good idea.

I should really stop insulting stupid people by associating you with them.

Yea, I get it, we are going to go to the Moon to make "ceramics". Thanks, I didn't understand that before, but now I do.

You dismissed the lunar regolith as being worthless, it isn't.

If Obama had said we should go to the moon, rderp would be cheerleading moon mining.

 

[daveman]

You know what's hilarious is when an object is spinning and you land on it. Imagine the center of a "merry go round". You can sit in the exact center and feel no "pull". It would be the same with an asteroid. When it rotates, the axis is relatively slow. That's where you would land. Did that really have to be explained? I was waiting, but no one figured it out. Sad.

Gonna have a tough time if the spin axis isn't aligned through to long dimension of the asteroid...or if it's spinning in two axes.

Maybe Obama can speak the asteroids into not spinning.

 

[Quantum Windbag]

You know what's hilarious is when an object is spinning and you land on it. Imagine the center of a "merry go round". You can sit in the exact center and feel no "pull". It would be the same with an asteroid. When it rotates, the axis is relatively slow. That's where you would land. Did that really have to be explained? I was waiting, but no one figured it out. Sad.

The reason no one figured it out is because IT DOES NOT WORK THAT WAY.

Why don't you dig out an old turntable, turn it on, and then land a toy helicopter in the exact center of it? After you watch it fly off a few times because you did not match the rotational vectors exactly you might get an inkling of just how hard it is, and realize just how stupid and ignorant you are.

 

[Quantum Windbag]

You know what's hilarious is when an object is spinning and you land on it. Imagine the center of a "merry go round". You can sit in the exact center and feel no "pull". It would be the same with an asteroid. When it rotates, the axis is relatively slow. That's where you would land. Did that really have to be explained? I was waiting, but no one figured it out. Sad.

Gonna have a tough time if the spin axis isn't aligned through to long dimension of the asteroid...or if it's spinning in two axes.

Maybe Obama can speak the asteroids into not spinning.

Gosh, look at that, daveman understands more about the problems than rdean.

 

[daveman]

You know what's hilarious is when an object is spinning and you land on it. Imagine the center of a "merry go round". You can sit in the exact center and feel no "pull". It would be the same with an asteroid. When it rotates, the axis is relatively slow. That's where you would land. Did that really have to be explained? I was waiting, but no one figured it out. Sad.

Gonna have a tough time if the spin axis isn't aligned through to long dimension of the asteroid...or if it's spinning in two axes.

Maybe Obama can speak the asteroids into not spinning.

Gosh, look at that, daveman understands more about the problems than rdean.

And I'm just a dumb science-hating Republican who wants to burn scientists and teachers at the stake.

Well, according to rderp.

 

[daveman]

Where'd rderp go?