China is rapidly expanding its secretive Lop Nur test base as its sixth-generation air race with the United States intensifies. Satellite images cited by the South China Morning Post reveal four new hangars, expanded taxiways and other facilities at the remote Xinjiang site, effectively doubling the base's footprint. The buildup comes after China's J-36 and J-50 next-generation aircraft were spotted there, while massive new hangars have revived speculation about the elusive H-20 stealth bomber. With Beijing also expanding aircraft infrastructure at Chengdu and Shenyang, is Xi preparing an even bigger air-power surprise away from America's eyes?