About today's launch it is

• The 353rd Delta rocket launch since 1960
• The 16th Delta 4 rocket mission since 2002
• The 13th Delta 4 rocket launch from Cape Canaveral
• The 7th Medium+ 4,2 configuration to fly
• The 9th Delta 4 under the ULA banner
• The 2nd Delta 4 launch this year
• The 12th use of Delta 4 by the Air Force
• The 5th classified Delta 4 for the NRO 

The classified payload is satellite for the NRO some think it's a communications satellite called an SDS.