Keith Henson, "$100 a kg to GEO with Beamed Energy Propulsion"

Keith Henson explored some of the issues in building about a solar collector in space.  He is looking at building a 500,000 thousand a year transport system of putting material into space.  (This would be 30 tons an hour into Geo orbit.)  He says could have about $50 a kilogram.  You might be able to start as small as 500 Megawatts and bootstrap yourself up.  Keith says we could have enough solar collectors in a decade to take the planet off fossil fuels.

There were several questions on the political issues of have a mega-laser in space. 

This was similar to a talk he gave back in 2009.