Thanks JJJ,
Watching now.
I did a Google and found this background story regarding the payload -
http://www.nasaspaceflight.com/2012/...aunch-nrol-38/
"Carrying the NROL-38 payload for the US National Reconnaissance Office".
Specifically, speculated to be part of the Satellite Data System in which case it is destined for a geosynchronous orbit.
"The Satellite Data System is a series of spacecraft used by the NRO to relay secure communications to and from reconnaissance assets, including other satellites."