你们见过间谍飞机、直升飞机、航天飞机吗？

Have you seen spy planes, helicopters and space shuttles?

雷达是一种发射无线电波寻找类似间谍飞机等移动物体位置和速度的装置。

Radar is a device that sends out radio waves for finding the position and speed of a moving object such as a spy plane.

上世纪50年代晚期，神秘的美国51号区，一架钛材料A-12间谍飞机原型机准备接受雷达测试。

Suspended upside down, a titanium A-12 spy-plane prototype is prepped for radar testing at Area 51 in the late 1950s.