[ExI] Mining the Sky SL Talk I gave today

Tom Nowell nebathenemi at yahoo.co.uk
Mon May 3 13:41:54 UTC 2010


Regarding sending cargoes back to earth - has anyone else read "Man and the Planets" by Duncan Lunan? It was quite popular back in the 80s in the UK. The chapter on asteroids includes a good table of asteroidal composition of rocky asteroids, although it's probably very out of date now.

This book is an enthusiastic cheerleader for the "Waverider" concept of lifting body. These have the effect of generating the re-entry plasma underneath the airframe only, so keeping the upperside clear and exposed to lower temperatures. In addition to allowing some forms of gliding re-entry missions on planets with atmospheres, it also allows you to keep in radio contact with re-entering objects. This will allow you to track objects in re-entry, and allows the possibility of radio control from earth.

Another good method for taking objects down to earth would be the continuous loop style of space elevator - this would allow you to use the energy of what's coming down to offset the energy you expend lifting things up. As I understand it, this style of space elevator is massively more demanding than simpler designs relying on a tapered cable and beamed power, and the simpler designs are still beyond current technology. Still, once we're dropping high-value cargo down from orbit, I'm sure the commercial demand will drive development of more efficient uses.

Tom


      




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