High-level Air Force and Defense Department officials are in “intense discussion” over whether to enact the waiver that would allow the service to use Russian-developed RD-180 rocket engines banned for future use in the fiscal year 2015 National Defense Authorization Act (NDAA).Air Force Space and Missile Systems Center (AFSMC) Commander Lt. Gen. Samuel Greaves told reporters Tuesday he hoped a decision would be made soon. The Air Force is under pressure to get moving on its plan for future procurement…