Orbiting factories

[silvermoonblade]

Out of curiosity,wouldn't the easiest way to build a self-sustaining space infrastructure be to capture football stadium or bigger meteors and put them in orbit around the Earth and use them as staging grounds for factories in space to build a larger infrastructure?

 

[docm]

It's pretty dangerous to intentionally move asteroids near the Earth for any purpose; one error and you could well cause a catastrophe. <div class="Discussion_UserSignature"> </div>

 

[webtaz99]

Surely they could be captured into Lunar orbit first, then transferred to Earth orbit. <div class="Discussion_UserSignature"> </div>

 

[annodomini2]

<blockquote><font class="small">In reply to:</font><hr /><p>Surely they could be captured into Lunar orbit first, then transferred to Earth orbit. <p><hr /></p></p></blockquote><br /><br />If you're gonna do that you may aswell smash them into the moon much less energy required (assuming they're not going too fast! <img src="/images/icons/wink.gif" />) <div class="Discussion_UserSignature"> </div>

 

[j05h]

<i>>Surely they could be captured into Lunar orbit first, then transferred to Earth orbit. </i><br /><br />Any deliberate capture into cis-Lunar orbits of asteroids will require some kind of national/world consensus. There are huge risks involved, both to space infrastructure and the Earth. Any mistake is only a few hundred m/s d-V to an impact. <br /><br />What would you need an entire asteroid for? Feedstocks? It'd make more sense to move the extraction equipment to the asteroid, then ship materials to the factory. Once the economics and tech make sense, just send the whole factory to the target asteroid. Moving asteroids by ejective power (water STR, mass-driver, etc) generally uses a sizable portion of the body as reaction mass. It might not make economic sense to waste all that when final product can just be shipped via solar sail or other method.<br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[kelvinzero]

It would certainly worry people, but would it really be remotely dangerous? It would be the best tracked NEO anywhere. Surely the trajectory could be designed so any failure of the propulsion left it on a safe course.<br /><br />I assume there is no reason to make it earth endingly large. Im more worried of all the things people deliberately do to each other.<br /><br />What is the nearest object that could contain water etc, or more interesting materials than moon regolith anyway?

 

[Boris_Badenov]

This thread has the necessary equations you are looking for;<br /><br /> Near Earth Asteroid Relocation <br /><br />Moving an asteroid has tremendous advantages, but it would be a massive effort. <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[qso1]

I would say that it would not be easier than sending up a series of preassembled factory spacecraft into low orbit to begin manufacturing whatever is required to develop orbital infrastructure. The orbital infrastructure would eventually be self sufficient. Humanity has yet to do something on such a large, and dangerous scale as asteroid relocation. One day it may well be possible and economical to do but I don't think we will see that day anytime soon. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[rpmath]

<font color="yellow">Moving an asteroid has tremendous advantages, but it would be a massive effort.<br /></font><br />what about moving smaller rocks?<br />...for each big near Earth asteroid there are many small ones.<br />You will need a big telescope to track 10 or 20 meter rocks but they are easier to move, if you look to many of them you can find some ones in good orbits or made of the right materials...<br /><br />May be it will be hard to find water in the small ones, so it must be extracted from bigger rocks in the asteroid belt or comets, but why to move the whole rock?<br />its easier to just cut and ship chunks with the right size.

 

[qso1]

A far more reasonable proposal. There are a few reasons for moving large ones but there are a lot more reasons I can think of off hand for moving smaller ones and it would not be nearly as dangerous. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[nexium]

Smaller than a stadium could kill a satellite, but would probably burn up in Earth's atmosphere, whether deliberately or accidentally moved too close to Earth.<br />Cutting pieces off with explosives could cause a piece to strike Earth, perhaps decades later, so it would be prudent to be sure all the pieces are smaller than a stadium. As someone posted, the small ones are much more abundant, but harder to find. I suspect that even the stadium size would cost more than a million times a million dollars to get in Earth orbit, with technology likely before 2020. Lunar orbit before Earth orbit would more than double the moving cost and reduce the hazard little or none. Neil

 

[qso1]

Your right, a stadium sized asteroid would be hugely expensive to bring to earth with technology likely before 2020. I don't expect there will be any asteroid relocation efforts much before 2075 at the earliest and then only if the need actually arises. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[webtaz99]

It doesn't take much delta-V if you give it 50 years to do its job..... <div class="Discussion_UserSignature"> </div>

 

[qso1]

True, but the fifty year transit will involve significant cost associated with personnel and equipment required to track it. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[scottb50]

It seems to me the effort needed to bring an asteroid into a convenient orbit would be a lot more then mining it in it's original orbit in multiple missions over a long period. <div class="Discussion_UserSignature"> </div>

 

[thebigcat]

I know that a lot of Buckeyes fans would love that picture. <div class="Discussion_UserSignature"> </div>

 

[thebigcat]

As near as I can see this is a pipe dream. And why borther, really? So that we can make use of microgravity to alloy lead and aluminum? The problems associated with manipulating molten metals in microgravity make this a nightmare scenario.<br /><br />The fact is that there is precious little in the way of proposed orbital factory products, from what I have seen, that could not be produced easier and safer in the 1/6 G found on the surface of the moon. <div class="Discussion_UserSignature"> </div>

 

[kelvinzero]

One advantage of asteroids is that some contain significant amounts of carbon, which is basically absent from the moon.<br />http://en.wikipedia.org/wiki/C-type_asteroid<br />I think some hydrogen is also present. Ceres has a lot, as water.<br />http://en.wikipedia.org/wiki/Ceres_%28dwarf_planet%29<br /><br />..on the other hand, there is the possibility of such asteroids having collided with the moon in the past and thus being accessable to mining. Another reason the moon deserves a much closer look.

 

[qso1]

If utilizing todays tech it would. However, one possibility for at least minimizing that impact would be to start mining as the asteroid is moved to earth orbit. At the moment, either method is a viable possibility. Its just going to depend on who can prove which one is the more practical method. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[spacester]

Asteroids have two main resources: Volatiles (water) and metals.<br /><br />Water is the killer app. But you want to bring the minimum amount of equipment to the roid and you want to leave it there and ship water back somehow. All robotic operation: manned missions are quite doable, BUT repeated trips to the same roid are going to be very expensive in either time or propellant. You have to wait for the (Near Earth) Asteroid and Earth to line up again, and that can take years. Astronauts <i>could</i> set up operations and return home, but they're not going to be returning to that particular object any time soon, not without long waits or extended voyages or LOTS of propellant. <br /><br />Metallic NEOs follow the same logic: ship back at least rich ore, not just unprocessed material, and hopefully final product ready for use on-orbit. Class M (Metallic) Asteroids might have powdered metal, but it might also be the case that the bast stuff is in very massive chunks: a mountain-size solid mass of 'space stainless steel'. Plasma torches could cut away a large chunk to ship back to cis-lunar orbit. <div class="Discussion_UserSignature"> </div>