SPS demonstrator risk assessment

[Sam Fraser]

[Moon, Mars and NEO missions] aren’t the only options available to the Shuttle Derived Heavy Lift Launch Vehicle (SD HLV).... Launching a SPS demonstration mission would provide tests not only for the SPS concept, but also “underscore” the capability of the SD HLV... Such a mission would likely provide an opportunity for the HLV to stretch its legs on an opening operational mission, as soon as 2016...

http://www.nasaspaceflight.com/2010/07/sd-hlv-early-sps-demonstration-risk-assessment/

Has the SD HLV only been proposed or actually approved?