The aircraft is a collaborative effort between the U.S. Air Force Research Laboratory, the Defense Advanced Research Projects Agency, Boeing and Pratt &Whitney Rocketdyne.
这架飞机是美国空军研究实验室,美国国防部,波音公司和普惠洛克达因公司的共同研究成果
3
The Pentagon’sMissile DefenseAgency is currently installing six interceptor missilesat Fort Greely in Alaska, and four at Vandenberg Air Force Base inCalifornia.