Towing Asteroids

[JohnHunt]

Logan Knox > Towing asteroids

NEO's (asteroids) are not going to be allowed in earths Sphere of influence. The public would be outraged by the danger inherent in such a plan. Even if the roid is not large enough to do any damage, people will be concerned and it will be all around bad PR to tow a roid close to earth.

Even mitigating this by taking it to the moon for processing may even be a PR blow to a company attempting to do so. The risk is not that the roid will do damage, the risk is the negative publicity generated by the task. Even if the fear is unjustified, it will still foment opposition.

Many public opinions are irrational, true. However, there are things which could be done to manage it. First, as would be expected, to test the idea a very small asteroid could/would be moved into orbit around the Earth. If it was small enough it might not even be able to make it through the atmosphere. That would be pretty small, indeed.

But secondly, it could be sent into an orbit around Earth which was very far out. Perhaps even further than the orbit of the Moon.

Also, the method of capture into Earth's orbit could be done, I believe, in a way in which the orbital pathway never actually crosses the Earth. If at any point in the process the tug craft were to malfunction, the orbit of the asteroid would be well away from the Earth. No country could claim that such-and-such country or company was putting them in the cross hairs.

Also, there is often a legal mechanism to push something through. Think of how many complaints there were about the dangers of the LHC, or NAFTA, or, well, for that matter the Iraq War (but that's a whole different story!) And yet all of those still proceeded.

My point is that public opposition doesn't always stop something.

[Rhyshaelkan]

I see pushing an asteroid to EML4 or EML5 to be most appropriate. That way even if things go wrong, it is more likely that an impact would not happen.

I would not be supportive of pushing an asteroid to LEO though. GEO is a better alternative. LEO will give negligible but significant atmospheric drag over the years and for the size of objects. GEO has orders of magnitude less atmospheric drag so that an asteroid pushed there would stay there for millenia.

With an 80km asteroid at L4 and L5 you could hollow out concentric rings in the heart of asteroid. Then impart a spin so that the inner-most ring has perhaps .7 . This is the park area to give a semblance to Earth. Habitation zones will be one ring out. Waste handling, crop production, livestock, manufacturing, schools, administration, all could reside in one of the multitudinous shells. It could be quite self sufficient.

You could copy this design to any of the myriads of asteroids in the main belt. Asteroids on the near side of the main belt could still use solar power as their major power source. On the far side of the main belt nuclear would probably be the main power source.

This design is not first generation though. Not really the insurance policy you are looking for. More of longer reaching aims. Point being though, our solar system could support population in the trillions given the resources we have. So that not one catastrophe would wipe out mankind. Unless Sol decides to do us in. ;)

[JohnHunt]

Yes, LEO is obviously out due to atmospheric drag. Very good point.

Now, is GEO necessary? Is there some value to having our asteroid always at the same point in the sky? I suppose if our asteroid was used to create GEO objects (a reasonable assumption) then having the material already in that orbit would be an advantage. So yes, it seems to me that GEO is the place.

Now, L4 and L5, these locations are nice because you can get from there to anywhere else in the solar system for little more delta-v, yes? But is that what we are wanting for our asteroid. For the first asteroid, I am thinking that the market would mostly be GEO and LEO. So it would take a lot of trips to get stuff from L4/5 to GEO. Why not just put it in GEO?

> That way even if things go wrong, it is more likely that an impact would not happen.

When placing the asteroid into GEO one could approach that orbit by taking an outside track and reducing the orbit until it is in GEO. That way Earth is never in its pathway. I can't imagine what possibly could go wrong (famous last words!) that would move an object from GEO into Earth-crossing orbit. I really don't see any risk.

> With an 80km asteroid
Yes, but this would be well into the future. I'm thinking about some of the first asteroids. What size would the first major one be? I'm thinking somewhere in the neighborhood of 100 meters in diameter. So it would be small enough so that an attached sail of reasonable size would get it into the designated resting spot. But it would be large enough to be of value commercially for a few years.

> This design is not first generation though. Not really the insurance policy you are looking for.

I moved this discussion from the previous thread so that we could just focus on moving an asteroid. Feel free to discuss this in the context of commerce.

[Rhyshaelkan]

1km would be best, in my opinion. A tiny asteroid in the scheme of things. 1km is about the threshold to generate an 1g environment without upsetting the inner-ear balances. If hollowed out and/or the material used to build a 10m shell it would be quite resistive to solar radiation.

Then again a smaller 200m asteroid would have the material available to build a large structure with a thick enough shell to resist solar storms. Multiple concentric shells would rapidly increase the square footage that can be utilized for self-sufficiency(just like adding a basement onto your home). Interior shells would not have to be as thick as the external, radiation proof, shell. Space can be quite hazardous, but well within the realm of feasible.

[JohnHunt]

The following website suggests that 224 meters is sufficient to achieve 1g and no significant inner ear problems. If we were willing to live with artificial gravity at about .6 or .7 then it could be smaller.

http://www.absoluteastronomy.com/topics/Artificial_gravity

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I am not looking at the first asteroid being a hollowed out habitat but rather for space-based materials. In fact, I'm guessing that the first towed asteroid would be a high-volatiles, small comet.

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> Multiple concentric shells would rapidly increase the square footage

Cool! And if you wanted to loose some weight, all you would have to do is to walk up to the 5th floor!

[Phenix]

Thanks a lot for opening this thread.

I do agree 100 % with Rhys and I would have written the same. Yes, EML4 for towing an asteroid will be the first stepping stone for opening the "industrial space age" door as the best resource location. Yes it would certainly be best to select an asteroid with high volatiles concentration for refuelling etc... Then towing an asteroid with high minerals concentration to the EML5 would then provide the raw materials to build objects at GEO. I can guess, that alternating volitiles/minerals rich asteroids will provide at a certain point self-sustainability.

As I stated the first industrial infrastructure should be build at GEO. Simply because it is best fitted location as the first hub for volatiles/minerals processing with of the aid robotics with or without mankind with an affordable life supports system.

I do not agree that the public opinion would see those asteroids following the Moon path with some critisism arguments. I would think the contrary that the public would see that as a revolution where the intelligence of the spirit has finally control on the matter.

The safest thoughts ;)

[Rhyshaelkan]

However if you had your asteroid at L4 or L5 why not build your manufacturing center there too. Refine on site, build on site, colony habitat on site. Now you would no longer have to cart your human miners back and forth wasting fuel.

The first manufacture might be tele-operation. And then turn into tele-operation and human presence in micro-g. And finally when an rotating habitat could be built, humans could stay indefinitely without fear of micro-g's affects on human physiology.

We need to find an nice all-purpose asteroid which will supply fuel to push it to L4 or L5. There is no way we could hope to push an asteroid with Earth based fuel. So probes defining the make-up of our targets is paramount.

[Phenix]

Ok, so how do you resolve life support systems including food supplies etc...?

[Rhyshaelkan]

Same way you would if you built it at GSO.

For ongoing life you need:

O2, C, CO2, N2 plus minor amounts of assorted minerals.

Any of these that can be found on the asteroid will allow you to not bring them from Earth. If you do not have them on asteroid,, bring them. Life support has been going on at the ISS and submarines for a long time now. It is not like we have to reinvent the wheel.


Edit: GSO or GEO is not that much different from L4 and L5 by delta-v

[Phenix]

More precisely how would you create real food from asteroids then ?

[Rhyshaelkan]

Most likely hydroponics or aeroponics (http://en.wikipedia.org/wiki/Aeroponics). So that you can avoid the massive import of soil. All you need is water and minerals(plus the aforesaid carbon and nitrogen). All of this is tested, little to no research required on our part.

[Phenix]

Ok, I am convinced now. I was not sure how that creating food in space is possible without Earth based supplies.

I still think the first space infrastructure as the main factory should be in GEO/GSO would bootstrap other infrastructures needed as pre-requesites and be moved to EML4 and EML5.

For larger asteroids in the SEL4, the main factory would bootstrap those as massive infrastructures.

[Rhyshaelkan]

Well what would be your first step? To build at GEO we will need material at GEO. That will have to come from somewhere. Earth, Moon, or asteroid those are our only options.

We will have to cart material from an asteroid to GEO from its orbit. Or move the asteroid closer to Earth, which is the original topic of the thread. But if you move it closer to Earth to be usable by Earth where to we put the asteroid. We might get huge outcry from people if we try to park the asteroid too close to Earth. Heck, I would be opposed to having an asteroid at GEO or, heaven forbid, LEO. So that leaves us with one of the E-M Lagrangian points, as that would be close by enough for us to use cost-effectively.

But then if it is at one of those nice L-points why not build there instead of GEO. We would have to move less material.

I am just trying to explain it logically =) cost versus benefits.

[Phenix]

The first the main factory as the "first stone" needs to be completely thought and engineered with robotics and teleoperation in the event to be built at E-M lagrange points from your thoughts. That means also that mankind for this "first stone" is out of the equation. Do you agree with this assumption ?

I would not go in that direction, I would first build the factory with the mining modules and transports vehicules such as cargo spacecrafts. Every object is teleoperated and has robotics.... The transports would tow the asteroids and transit the materials and volatiles extracted from the mining modules back to the factory. Then the infrastructures bootstrapping process would occur.

[Rhyshaelkan]

For an first mission I am rather against an manned mission, due to the requirements involved. However I also know the arguments for an manned mission. It is not an easy decision.

Robot mission, one wire is crossed = game over
Robot mission millions of miles from earth = you cannot make snap decisions like Neil Armstrong did on the first lunar landing


So it is not easy. They both have big argument points. However NEAR Shoemaker (http://en.wikipedia.org/wiki/NEAR_Shoemaker) did land remotely on an distant asteroid. So...

[Phenix]

Yes, that is also a point I am wressling with, and I think that a manned mission and infrastructures fitted for mankind will come after the "first stone" and not before because the confort circles will come after the first stone settlement. It does make sense such as the house construction analogy.

[JohnHunt]

I also favor robotic missions to an asteroid being teleoperated robots. However, bear in mind that the current reality is that NASA may first send a manned mission to an asteroid with no intention whatsoever of developing it in any way. This is the incredibly wasteful consequence of the Glory and Discovery motivations.

Now, given this likelihood we may want to bear in mind how the manned NASA plans to visit an asteroid might be leveraged. For example, should we start now by identifying and advocating for a specific volatile-rich asteroid and imagining what the astronauts might do to facilitate the asteroid's transport or development? Also, by advocating associated robotic and development missions to that asteroid, we might be able to direct the discussion to the relative merits of a manned vs robotic asteroid missions. I think that that discussion could only be beneficial.

However, I am presuming that any asteroid that NASA would want to go to is probably going to be a pretty large one. Any ideas if it is realistic to, afterwards transport such a large asteroid to GEO?

[moonus111]

I don't think NASA will actually send men to an Asteroid. Another politician will come along, cancel the plan, and set new plans for sending men to wherever his whim is.

There is a way to stop this, but by now you prolly know what I'm going to say...

.... blah blah blah people blah blah blah spread word blah mainstream idea.

[Rhyshaelkan]

We(whomever wishes to push an asteroid) need better engines. And/or a constant source of fuel from said asteroid. Depends on the size of your asteroid as well.

Not until we have higher power plasma or fusion drives do I think we could accomplish moving an asteroid. Well, unless you wanted to do solar sails. But that would take long too. Plus you do not have complete control of the "winds".

[Sam Fraser]

I've been sceptical about the feasibility of towing an asteroid, but what about a "bubble sail"? See page 15 here:

http://www.niac.usra.edu/files/library/meetings/fellows/mar07/1314Crowe.pdf

[joertexas]

I don't think NASA will actually send men to an Asteroid. Another politician will come along, cancel the plan, and set new plans for sending men to wherever his whim is.

There is a way to stop this, but by now you prolly know what I'm going to say...

.... blah blah blah people blah blah blah spread word blah mainstream idea.

At this point, I'll take a manned mission to anywhere from NASA. We need to develop a manned spacecraft again, and soon. My vote is for SpaceX, but I'm not picky as long as it flies soon, and it flies from the US of A.

It's not that I have anything against anyone else's space program, but I'd like my own nation to have the capability, too.

JR

[Phenix]

I also favor robotic missions to an asteroid being teleoperated robots. However, bear in mind that the current reality is that NASA may first send a manned mission to an asteroid with no intention whatsoever of developing it in any way. This is the incredibly wasteful consequence of the Glory and Discovery motivations.

Now, given this likelihood we may want to bear in mind how the manned NASA plans to visit an asteroid might be leveraged. For example, should we start now by identifying and advocating for a specific volatile-rich asteroid and imagining what the astronauts might do to facilitate the asteroid's transport or development? Also, by advocating associated robotic and development missions to that asteroid, we might be able to direct the discussion to the relative merits of a manned vs robotic asteroid missions. I think that that discussion could only be beneficial.

However, I am presuming that any asteroid that NASA would want to go to is probably going to be a pretty large one. Any ideas if it is realistic to, afterwards transport such a large asteroid to GEO?

John, my point on this is to tug/tow asteroids to EML4 and EML5 and not use the Moon for its resources but because the Moon is the nearest gravitational body fitted with Lagrangian points. I think it will cost less and be safer to mine the asteroids at EML4 and EML5 and bring the industry and habitats bootstrapped from GEO to those Lagragian points. Setting up the magical triangle GEO, EML4, EML5 should be the priority number one to raise the first industry and dawning the Space Economy for the wealth of everyone on Earth.

Having one asteroid at GEO will scare everyone.

[Rhyshaelkan]

Current engines do not have the thrust to tow an asteroid. So it is rather out of the scope of PERMANENT's plans.

Even a mission to an asteroid is looking questionable after JR has been running mission calculations. Our main focus will, for the foreseeable future, probably turn towards industrialization of Luna. At the very least a fuel depot. Which will open up more options.

[joertexas]

Current engines do not have the thrust to tow an asteroid. So it is rather out of the scope of PERMANENT's plans.

Even a mission to an asteroid is looking questionable after JR has been running mission calculations. Our main focus will, for the foreseeable future, probably turn towards industrialization of Luna. At the very least a fuel depot. Which will open up more options.

The killer is the 10.5 km/sec or better Dv to get out there and back. That's the equivalent of putting a complete booster into orbit. With any conceivable budget we can generate, that's probably not going to be possible.

If we can either get much better engines, or fuel up from Luna, then we can step out there.

JR

[moonus111]

Man when we finally get there roids are going to be the awesome cool stuff in the solar system.

[Rhyshaelkan]

And we are certainly not turning our back on 'roids. When we get a fuel station on Luna then we can get back to 'roid mining. We will need to anyway for volatiles, and rare earth elements for our manufacturing endeavors.

[joertexas]

And we are certainly not turning our back on 'roids. When we get a fuel station on Luna then we can get back to 'roid mining. We will need to anyway for volatiles, and rare earth elements for our manufacturing endeavors.

Exactly right. And, we will hopefully have better engines that will make the job that much easier..

JR

[JohnHunt]

> Current engines do not have the thrust to tow an asteroid.

Well, that entirely depends upon the size of the asteroid in question. Periodically we are being buzzed by pretty small asteroids which are smaller than the size of upper stage fuel tanks. We can accelerate fuel tanks to escape velocity, certainly we can move small asteroids into an orbit of our choice.

[Rhyshaelkan]

However will those small asteroids be worth the price of the launch.

Even with the high current price of platinum ($1700/oz. last checked a few days ago). It would take several tons of platinum for the mission to break even. The smaller the asteroid the less likely it will have the stuff we want.

On the other hand if it is an ice-ball then you could crack the water-ice into fuel and sell the fuel for a decent amount at LEO.

[joertexas]

However will those small asteroids be worth the price of the launch.

Even with the high current price of platinum ($1700/oz. last checked a few days ago). It would take several tons of platinum for the mission to break even. The smaller the asteroid the less likely it will have the stuff we want.

On the other hand if it is an ice-ball then you could crack the water-ice into fuel and sell the fuel for a decent amount at LEO.

Once we get the moonbase going, then we can certainly reach out to the NEOs for the strategic metals and even more ice for fuel. As a nice bonus, we will have a pile of asteroidal iron, plus the odd platinum group metals find to sweeten the pot. Then, we will see how the naysayers like our bottom line.

JR

[Doug]

LEO/GEO will never fly as a first mission. Too many people/countries would be scared it would hit the Earth.

We need a proof of concept capture mission. It will not generate income, but it will show that we can do it. A small <= 100m asteroid to a EML point. Then we or other countries/Org's could send experiments to it. Mining or mineral processing or ????

Landing on the moon did not produce any income. In the process of getting there NASA developed lots of commercial spin offs. I hear there is a >$5 made per $1 spent by NASA on the commercialization of the spin offs.

[prometheuspan]

i'm dead set against earth orbit asteroids... isn't that what goddess put the moon there for?

Also, Earth trojan orbits...?

[Rhyshaelkan]

I am moving this topic to the Off-Topic section. As it is out of the realm of Near Term.

[joertexas]

i'm dead set against earth orbit asteroids... isn't that what goddess put the moon there for?

Also, Earth trojan orbits...?

I vote for using Venus to capture asteroids - I can't remember where I found the relevant articles about it, though...

JR

[joertexas]

not a lot of venus crossing asteroids and thats awful hot turf.

I'm all for it where they capture to venus orbit easily, but thats not a lot of asteroids.

An orbit is easiest to modify at perigee, so the idea is to practically skim Venus' atmosphere with the asteroid. Besides, this is a ways off - we don't begin to have the engines to accomplish the feat of actually steering an asteroid.

JR