The US National Reconnaissance Office’s NRO L-101 mission was launched successfully from the SLC-41 pad at Cape Canaveral Air Force Station at 2232 GMT on 13 November using a ULA Atlas V vehicle.  The spacecraft, which remains secret, was launched into a circular highly inclined Medium Earth Orbit at approximately 11,000km altitude and inclined at circa 58.5 degrees. The launch used a new version of the Atlas V 531 rocket fitted with three new GEM 63 solid rocket boosters – officially titled Graphite Epoxy Motor 63 which are built by Northrop Grumman. Extended versions of these will eventually be used by the Vulcan Centaur successor to the Atlas V.  The mission of the spacecraft or its design remains a mystery.

Atlas V 531/GEM 63 launches carrying NRO L-101. Courtesy: ULA