--- Eugen Leitl <[EMAIL PROTECTED]> wrote: > On Thu, Jun 14, 2007 at 11:05:23PM -0300, Lúcio de > Souza Coelho wrote: > > > >Check your energetics. Asteroid mining is > promising for space-based > > >construction. Otherwise you'd better at least > have controllable fusion > > >rockets. > > It is quite useful to utilize space recources where > they are, > because the hardware is there, and all you need is a > high-bandwidth > link, or dropping a matter packet with data.
Keep in mind the large lag time in lightspeed communications. This goes double for uploads and AIs who probably won't be running at human speed. > > (...) > > > > Not really. > > > > Elements that are incredibly rare on Earth - such > as platinum group > > Reasonably advanced nanotechnology (biological life) > doesn't > use large quantities or rare elements. A lot of > elements > people consider rare have actually quite nice crust > abundancies, > but lack ores. Any element that lacks a decent ore must have a small market, as it'd be very hard to get large quantities. Any small market will very quickly become saturated with the space-based production, causing the element to drop in value dramatically. > If you have good enough enrichemnet, > then > everything is ore. > > > metals - could be mined in asteroids and simply > dropped into Earth in > > round-of-the-mill reentry capsules - and those > would't even need > > rocketry tech beyond the current level. Take in > consideration that > > even a few tonnes of platinum - well below the > weight of the space > > shuttle - would be of immeasurable value. > > Sure, and don't forget to add some hand mirrors, and > glass pearls. Huh? > > As for "bulk" elements like iron, copper, nickel, > etc, there are small > > asteroids - a few tens of meters in length - that > could potentially > > have thousands of tons of those metals. My > suggestion for that would > > Why asteroids? The Moon is close enough, both in > distance, and > in terms of delta v. The Moon has very small concentrations of metal in the crust due to the method of its formation. > > be a controlled crash - simply boost the asteroid > (using a mass driver > > or whatever) to a trajectory where it will be > aerobraked by Earth's > > upper atmosphere (preferably over the ocean to > avoid hazardous > > hypersonic booms over populated areas) and then, > stripped of most of > > its kinetic energy, crash in an uninhabited area. > Probably the crash > > will still look like a small nuke, but then we > devastate similarly > > larger areas for comparable gains (as in the case > of hydroelectric > > plants or extensive surface mining). By the way, > talking about mining > > on Earth, some of the ore deposits currently > explored are in fact > > ancient asteroid crashes... > > Good luck finding an insurer for that. Also, simply crashing an asteroid onto the planet will vaporize all the ore and scatter it for dozens of kilometers in every direction. > > Finally, in the long term space elevators may well > be possible, and > > then the limitation of bringing raw materials from > space to Earth will > > be similar to the limitation of moving materials > between continents > > using ships. > > Look into linear motors on Luna, topped off with > rocket burn. > > ----- > This list is sponsored by AGIRI: > http://www.agiri.org/email > To unsubscribe or change your options, please go to: > http://v2.listbox.com/member/?&; > ____________________________________________________________________________________ Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=list&sid=396545433 ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=4007604&user_secret=7d7fb4d8
