China builds massive desert test facility to test future fighter jets as it races against US for sixth-gen tech

China is expanding its Lop Nur flight-test facility in Xinjiang to accelerate development of next-generation military aircraft, satellite imagery reviewed by SCMP shows. The buildout coincides with sightings of the J-36 and J-XDS/J-50 fighters, and has roughly doubled the base's size since 2025. The expansion has also renewed speculation about China's rumoured H-20 stealth bomber, though no confirmed link to the programme has been established.