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khoopes01
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can a small nickel/iron asteroid brought near Earth (matching its solar orbital velocity) and soft landed at the south pole where Earth's rotation is not an issue?
khoopes01 said:ok - so the asteroid free falls to its terminal velocity - remember, it is not in orbit but starting from rest. Could a system of parachutes slow it down enough to let it crash land (remember, we don't care if it is damaged.) 100 meters/sec would not do much damage on the south pole.
khoopes01 said:ok - so the asteroid free falls to its terminal velocity - remember, it is not in orbit but starting from rest. Could a system of parachutes slow it down enough to let it crash land (remember, we don't care if it is damaged.) 100 meters/sec would not do much damage on the south pole.
That's a big assumption depending on the asteroid.khoopes01 said:Assuming we can land it without burning it up, it is still an immense undertaking.
Big undertaking. But if we assume something like http://en.wikipedia.org/wiki/Skylon_( spacecraft )" succeeds then we're looking at a cost of ~600,000 dollars per tonne to launch to LEO with a 15 tonne payload per launch. From then on you're probably going to need something like an ion drive or VASIMR to launch equipment around the solar system.khoopes01 said:I think the following steps would be required:
- getting the stuff for the 'asteroid mission' up there at a minimum cost. Perhaps an
air breathing, tail first reusable craft to get the stuff into low Earth orbit.
I don't think solar sails would be good enough. It would need some sort of propulsion.khoopes01 said:- Can we use solar sails to get a robot to the asteroid belt to find 'candidates' of
the right size and composition?
If you want to land it you're going to need more than that! You'll need to attach significant rockets and fuel (probably more massive than the asteroid itself) to land it safely. Remember you are talking about shunting around kilo-megatonnes of mass!khoopes01 said:- Before going further, the candidate will have to have steering rockets at the end of tow
cables installed as well as hooks for sails and parachutes.
Er...maybe. Depends where it is.khoopes01 said:- Can we sling shot the asteroid around Jupiter under sail to direct it back to Earth
I don't see why impacting the moon and shooting smaller chunks to Earth would be desirable as you still have the problem of how fast they are going.khoopes01 said:All in all a very expensive mission (especially the first one.) It also may be possible to impact the asteroid on the moon and send the cut up pieces back to Earth by solar powered linear accelerators. Those asteroids could be big enough to be economically more feasible.
Nonsense, for several reasons.khoopes01 said:The asteroid in question is not an ELE sized rock but a carefully selected nickel/iron
asteroid as big as a house. Since it is starting from rest and not going 17,000 mph,
the use of steerable parachutes is feasible.
Which is it? 15 meters × 15 meters × 15 meters, or 1000 m3? Do your math right! Fortunately, Ryan did your math right for you in post #7.Space mining might eventually become a going venture, but never for something as common as iron, or even something like nickel which is about 20 times less common than iron (and hence about 20 times more expensive). It might be worthwhile for those common elements if the mined material is used to manufacture items in space, never bring them back to Earth. Mining things in space and bringing the refined material back to Earth might be worthwhile, but only for substances such as gold, iridium, and tritium that are several orders of magnitude more valuable than iron and nickel. And then it will be treated as the precious (and small) cargo that it is. It will not be dropped like a rock on Antarctica.A house sized asteroid (15 by 15 by 15 or 1000 cubic
meters would weigh 3375 *(450 lbs/cubic foot) = 1518750 pounds. Now that's a lot,
but multiple drogue parachutes could probably slow its descent. If not, we would select a smaller asteroid, or use solid rocket motors to slow it down.
An Asteroid One one tenth that size weighing 700,000 pounds would be worth 700,000*5.00/lb
=3,500,000 dollars (that buys a LOT of parachutes)
khoopes01 said:First, I would like to thank everybody on this thread for their input. I think we can put the Earth landing to rest as being impractical. However, there are 3 more logical targets out there - the moon, Mars, and Earth orbit where the nickel and iron would be very valuable. Someone is already thinking of mining lunar water and selling it in low Earth orbit (Shakleton mission.) So getting materials for space exploration from non-terrestrial sources is a very practical mission.
You're missing the point, Ryan. Raw materials mined in space could eventually become very valuable in space if that material is refined in space and then used in space to manufacture things. It costs a lot of money to launch anything into space. In-situ resource utilization is and has been a hot research topic in NASA. It is for the most part far term research of course; we won't see a space refinery and space metallurgy any where in the near future.Ryan_m_b said:I really don't see how any of that is economically viable. The sheer cost of the project would outweigh any gains. Think of it this way, every billion spent on pulling a few tonnes in space is a billion that could be spent on efforts on Earth prospecting/mining new deposits, recycling old materials and redesigning systems to run with less.
Here you are really missing the point. Water is far too common on Earth to ever make mining water in space and shipping it back the Earth an economically viable endeavor. However, just because water is cheap on Earth does not make it cheap in space. Launching water into space is expensive; launching anything into space is expensive. Water is one of those in-situ resource utilization capabilities that is not far into the future science fiction. Mining water on the Moon for use on the Moon could significantly reduce the costs of an extended lunar outpost.As for the moon water thing that leaves me gobsmacked. There is no way that regular Earth-to-Moon and back again mass transport as well as water mining in what is essentially a desert would be cheaper than a http://en.wikipedia.org/wiki/Desalination" station on the coast.
shashankac655 said:Asteroid mining
The figures given in this link makes me think that asteroid mining can become a reality ... probably by the 2nd half of this century or by the beginning of the 22nd century.
Ryan_m_b said:assuming this 1000cm3 asteroid was a 1:1 mix of nickel and iron that gives you 4451 tonnes of nickel and 3935 tonnes of iron.
Ryan_m_b said:The Earth's rotation is not an issue, the Earth's gravity is. Because of that anything that's near enough to feel its gravitational pull is going to plummet down. Considering the south pole is where so much water is kept I doubt dropping an asteroid at terminal velocity on it would do us any favours.
Ryan_m_b said:I'd be very careful about technological predictions, particularly ones to do with space. There have been predicted manned Mars missions for over 30 years and we're still not much closer.
Having an asteroids worth of material would be great and all but first the technology has to be there and that technology will always have huge ramifications on Earth first. Robots using resources in situ to build tools and other robots are hugely non-trivial. The technological hurdles are immense.
What's a few orders of magnitude typo between friends?Borek said:Last time I checked 1000cm3 of iron/nickel alloy didn't weight much more than about 8 kg
Another typo, I meant ice (implication being we'd like to keep it in it's frozen state).HallsofIvy said:Where so much water is kept? I had always heard that the center of antarctica was pretty arid.
Again I would be wary. The level of infrastructure and technology needed for asteroid mining is astounding. Most asteroid missions cost tens of millions and involve sending a few tonnes worth of probe. You're talking here about sending enough robotics to effectively mine and send back kilotonnes of material!shashankac655 said:yea ,but notice that ,the article says that we will run out of some important minerals in 50-60years and the amount of these minerals that are said to be present in those asteroids are astonishing! and their prize too.We don't need to send humans there do we? Robots can do the job(it can reduce costs) but still i accept that cost will always be problem.
Mars mission is a different story because if all these minerals are present in these asteroids ,why do we need to go to mars?we don't need to mine on Mars because it far more expensive because we will have to do atmospheric entries and overcome Martian gravity and all that ,it's unnecessary isn't it?
About robots building robots ,i agree with you.
Cosmo Novice said:I honestly think that commercial viability will be one of the core influences in space exploration/utilisation in the next few centuries.
Ryan_m_b said:We differ here, even with some astounding developments in space science I don't think commercialisation of space is that viable. At least not the kind of viable that allows for manned exploration and colonisation. On the other hand an economic environment where an entity has a large surplus of wealth and a willing population is a great place to start. I remain unconvinced that market forces and capitalist business models can ever produce the ++multi-trillion dollar, ++multi-decade investment that manned exploration and colonisation require.
A soft landing for an asteroid refers to a controlled and gradual descent onto the surface of a celestial body, such as a planet or moon, with minimal impact and disruption.
The south pole is a preferred location for soft landing an asteroid because it has a relatively flat and stable surface, as well as a consistent and predictable lighting environment that allows for better visibility and control during the landing process.
The potential benefits of soft landing an asteroid at the south pole include easier access to resources and materials that can be extracted from the asteroid, as well as the potential for scientific research and exploration of the asteroid and its composition.
Scientists plan to achieve a soft landing at the south pole through the use of advanced technologies and techniques, such as precision navigation and guidance systems, thrusters, and landing gear, as well as extensive simulations and testing.
The challenges scientists face when attempting to soft land an asteroid at the south pole include the need for precise calculations and timing, the potential for unpredictable terrain or surface conditions, and the potential for technical malfunctions or failures during the landing process.