Earth-Sun L4 and L5 best option for space mining?

[darthgently]

Here is the rationale:

1.  Lower DV to transfer to/from than asteroid belt relative to Earth

2.  Have been collecting useful stuff for aeons

3.  Once cleared out would make no-brainer stable orbit focii for large habitat orbitals and asteroid mining locuses as more stuff is naturally drawn in over time

 

[farmerben]

The best place to look for my keys is underneath a lighted lamp post.

[darthgently]

9 minutes ago, farmerben said:

The best place to look for my keys is underneath a lighted lamp post.

L4 and L5 are gravity wells that attract stuff.  The lamp post does not attract your keys. 

However, if  you have lost your keys and if  they somehow were subsequently accelerated just beyond Earth's escape velocity on a proper trajectory, then there is a non-zero chance you might find your keys eventually near L4 or L5 and it might be worth looking there.  The Sun will be your lamp so no need to take one with you

[farmerben]

 

Known asteroids of the inner solar system.  There is something at Earth's L4 and L5 so it might be good to check out first, there is just not much.  

[darthgently]

1 hour ago, farmerben said:

 

Known asteroids of the inner solar system.  There is something at Earth's L4 and L5 so it might be good to check out first, there is just not much.  

We need Earth-Sun L4 and L5 cleared of debris anyway if we are to make them safe for the huge orbitals, power farms, and manufacturing we could put there in relatively close access (measured in dv)  to Earth, so might as well mine it in place. 

Also, I'm not sure that map accurately reflects actual distribution.  It is almost certainly only objects above some size limit.  But yeah, OSIRS-Rex didn't find anything new when it passed near L4 apparently.

 

[farmerben]

https://en.wikipedia.org/wiki/(614689)_2020_XL5

There is one object 1.2 km in diameter.  Then there are a few notables in the 300m diameter range.  There is also a fair amount of dust at L4 and L5.

 

I agree it's a good spot to test out some of our technology.  The resources are however miniscule compared to all the other asteroids.

[kerbiloid]

15 hours ago, farmerben said:

The best place to look for my keys is underneath a lighted lamp post.

That's true, because the lamp posts attract humans and even dogs to do their things.
In evening it's almost the only place to do something with keyring, because it's dark around.

[darthgently]

4 hours ago, kerbiloid said:

That's true, because the lamp posts attract humans and even dogs to do their things.
In evening it's almost the only place to do something with keyring, because it's dark around.

If we are to account for dogs then we must account for crows.  Crows like to collect shiny things and nest up high.  So keys lost away from the lamp could end up very near the lamp; on top of the lamp, actually

[magnemoe]

14 hours ago, kerbiloid said:

That's true, because the lamp posts attract humans and even dogs to do their things.
In evening it's almost the only place to do something with keyring, because it's dark around.

I assume he implied under an lamppost is a good first place to look as they are easy to spot there. same with L4 and L5 is easy places to mine. 

[Gargamel]

On 8/7/2024 at 2:25 PM, farmerben said:

There is also a fair amount of dust at L4 and L5.

Dust gathering might be a good way to start expanding the techs required to make space mining a thing.  

[darthgently]

16 minutes ago, Gargamel said:

Dust gathering might be a good way to start expanding the techs required to make space mining a thing.  

Techniques for gathering small stuff would have crossover benefits for getting debris out of Earth orbit possibly also

[kerbiloid]

They should deliver and release several tons of air, then garther the dust with a simple vacuum cleaner.

P.S.
Interesting fact: vacuum cleaners are able neither to work in vacuum, nor to clean the vacuum.

[farmerben]

5 hours ago, kerbiloid said:

They should deliver and release several tons of air, then garther the dust with a simple vacuum cleaner.

P.S.
Interesting fact: vacuum cleaners are able neither to work in vacuum, nor to clean the vacuum.

That wouldn't work.

While the Lagrange points are technically single points, the tidal forces associated with them are so weak that they describe huge regions of space.  In the image posted above you can see the Greek and Trojan asteroid clusters at Jupiter's L4 and L5 points.  The influence of Earth's L4 and L5 are scaled similarly.

Edited August 10 by farmerben

[darthgently]

28 minutes ago, farmerben said:

That wouldn't work.

While the Lagrange points are technically single points, the tidal forces associated with them are so weak that they describe huge regions of space.  In the image posted above you can see the Greek and Trojan asteroid clusters at Jupiter's L4 and L5 points.  The influence of Earth's L4 and L5 are scaled similarly.

I imagine more of a constellation of mobile orbiting  sweepers, not something that sits exactly at the L waiting for stuff.

[farmerben]

Supposing you wanted to tunnel out a 1.2km asteroid, there is not much surface gravity to hold down the dust you make from excavating.  

It might be easy to dig however since lifting spoil costs almost no energy.  A good rotary head could grind and fling dust.  A little puff of gas now and then could help blow out the hole.  The thing is you need a tent like superstructure to catch your dust and let it pile up on the surface.  

[AckSed]

Might be time to dig out the studies on charged-dust droplet radiators and adapt them to Lagrange sweepers: https://ntrs.nasa.gov/citations/19870010920

[kerbiloid]

15 hours ago, farmerben said:

Supposing you wanted to tunnel out a 1.2km asteroid, there is not much surface gravity to hold down the dust you make from excavating.  

through which the tugs should be passing to dock.

14 hours ago, AckSed said:

Might be time to dig out the studies on charged-dust droplet radiators and adapt them to Lagrange sweepers

Are being studied as an option for the TEM/Zeus/Nucleon perspective nuketug.

Though, they are also not a silver bullet, as the metal droplets must stay liquid, so are limited with boiling point.

Edited August 11 by kerbiloid