Qian Qihu, 85, China's top defense engineering expert, has been awarded the August 1 Medal this year. He devised the theoretical system for China's modern defense engineering, and contributed to the creation of its underground defense infrastructure. In the 1960s, Qian began to study the protection against nuclear bomb explosions. Qian has since devoted more than 50 years to the study and made major contributions to building a series of defense facilities located deep inside mountains. Qian described his work as the "Underground Steel Great Wall" that can guarantee the security of China's strategic arsenal against various attacks, including those from hypersonic weapons.