Article is content free; here's the paper: http://www.nasa.gov/pdf/716070main_Mankins_2011_PhI_SPS_Alpha.pdf http://www.nasa.gov/pdf/716070main_Mankins_2011_PhI

Article is content free; here's the paper: http://www.nasa.gov/pdf/716070main_Mankins_2011_PhI_SPS_Alpha.pdf http://www.nasa.gov/pdf/716070main_Mankins_2011_PhI_SPS_Alph... 11,800 tonnes in GEO for 500 MW. At Proton-M prices, that's $295/watt for the launch. Not great…