The US government couldn't exactly hide the 72m-high Delta IV Heavy rocket that took off from Vandenberg Air Force Base on Thursday, but the details of what the military and intelligence craft was carrying into space are far more secretive. The rocket - the biggest to launch from the US west coast - was supposedly carrying a classified satellite for the National Reconnaissance Office (NRO), to be put into polar orbit.
Exact specifications on that satellite are unknown, but the NRO does supply information to the CIA and US Department of Defense, which has led to speculation that high-resolution imagery will be the main priority. The Delta IV has a payload space measuring roughly 63 feet in length and just short of 17 feet in diameter.
Upgrading the SLC-6 launch pad for the Delta IV cost around $100m, though it's expected that the site will be used for more launches now that the investment has been made. While discussions have taken place about using the rocket for manned missions, at present only military and intelligence missions have been undertaken.