In addition, the USAF continues to fund development work of the Aerojet (formerly Atlantic Research) Variable Flow Ducted Rocket ramjet system as a future propulsion option for an extended range AAM.

此外，美国空军继续投资于航空喷气研究所（原来的西研究所）的可变喷流管火箭发动机系统，将其为增程空空导弹的未来推进选项。