Orbital ATK [OA] hopes to beat competitors to the launch pad by having its next-generation Evolved Expendable Launch Vehicle (EELV)-class rocket fly its first Defense Department mission in 2019, according to a company spokesman.Orbital ATK spokesman Barry Beneski said Wednesday the new EELV class rocket will have solid motors for the first two stages and a liquid upper stage engine. Orbital ATK is developing its EELV-class rocket under a $47 million other transaction agreement (OTA) contract awarded by the Air…