Discussion on:

Want to intern for an asteroid mining startup?

Everyone knows how expensive it is to get mass out of a planetary gravity well. I think a lot of people forget that it would also be very expensive to bring mass into a planetary gravity well. Oh sure, we can bring stuff down fast and hot pretty easily - but we are also then adding undesireable polutants into the atmosphere - top to bottom; and we also have a fair idea what happens when objects stop fast (hit the earth) at the bottom.

With the exception of very rare or very light resources, the best current use of asteroid mining is to manufacture goods in space that stay in space.

Agree... Men would have to find ways to use the Lagrangian points available in the systems made of any two big mass bodies, such as Moon and Earth, for example, and 'park' their manufacturing facilities in Space, or get them to the Moon, and only export to Earth things that really worth doing. Water, for instance, may become a hot product since population does not stop growing. But I guess, it could just be left in orbit to slowly be falling toward the planet. Problem is, how do you 'charge' for it, since it would mix with the atmosphere's.

While I agree with most of what you say water is not in any way in short supply on the planet Earth. There are some regions where it is but supplying it from space is not an answer. After all sea level is rising fast enough on its own.

Asteroids and comets have been hitting the earth for billions of years. While nobody wants one to come down now, scientists think they are responsible for many of the resources on earth, especially water.

However, all it takes to safely bring down mass is what we used for bringing down our space capsules. Ablation shields and parachutes are relatively cheap, probably could be manufactured from materials on the asteroids, and leave the cargo intact.

And at some point we may come up with space elevators, which would make bringing down mass easy. We could even convert the enormous potential energy of a mass in orbit to electric power, though with easy access to space and solar energy probably nobody would bother.

In line with Mr. Johnson's above comment: The only intern position worth having in this venture would be as an intern to the project economist, assuming there is one. If there is such an economist on board, interning under said economist would the equivalent of an opportunity to intern under the world's greatest master magician - a magician capable of pulling a a giant hat out of a garden variety rabbit.

While I admire Mr. Cameron's ambition and imagination, his understanding of economic probabilities are sadly lacking - while his understanding of critical earth resource priorities is non-existent. It's always easy to stir ones imagination with the possibility of vast wealth. From man's survival perspective one resource's availability under it's current economic paradigm should take precedence over all others. Given current world population, and expected growth in the next 50 years, the world is going to run out of cheap rock phosphate as a resource to fuel its Green Revolution's food machine - which 95% of the earth's humans are already absolutely food dependent upon. In spite of 40 years of intensive R&D on replacing our diminishing reserves of cheap rock phosphates, no new economically equivalent phosphorous source has been developed. Without phosphorus to make the petroleum dependent NPK fertilizers, the earth's natural phosphorus replenishment cycle is only capable of maintaining about 2 billion people, not the 7 B we have now not the 10-15 50 years from now. Mr. Cameron, quit pissing away your resources and prioritize their use.

The "Green Revolution's food machine" is not sustainable in any case, the depletion of cheap phosphate is the least of its problems. Big ag uses it very wastefully, which has led to phosphate becoming a major water pollutant.

We need to stop wasting animal manure, in the first place. The use of cover crops to take up soluble nutrients so they don't leach away is also of great value - buckwheat is especially good at capturing P and making it available to subsequent crops. The use of fungal inoculants to increase the conversion of P to forms available to plants is also proving very valuable - most soils naturally contain plenty of P, but in the wrong chemical compounds.

The initial concept has been around since the early 1900's, and in the 1970's they figured out how to do it. Nobody wanted to foot the bill to get the project going, even though it would more than pay for itself in the long term.

For anyone interested, the "Space Resources and Space Settlements (1977 study)" online paper from the National Space Society website has lots of detail on this in chapter 4.
http://www.nss.org/settlement/nasa/spaceres/index.html

BTW, in reference to the above argument, asteroids have Phosphorus, so problem solved