美国国家利益网站2016年10月19日刊文称,美空军X-37B空天飞机已累计飞行了500多天,这表明一场军事太空变革正在悄然展开。由美国波音公司研制的“轨道试验飞行器”(X-37B)是一款用于执行高保密任务的长航时可重复使用的无人空天飞机,最高速度能达到声速的25倍以上, The U.S. national interest website October 19, 2016 issue argues that the U.S. Air Force X-37B space plane has flown for more than 500 days, indicating that a military space revolution is quietly under way. The orbit pilot aircraft developed by Boeing of the United States (X-37B) is a long-haul reusable unmanned space shuttle designed to perform high-security missions at speeds up to 25 times the speed of sound ,