Why is the US military getting ready to launch new spy balloons?

The US military is planning to launch balloons that are capable of providing high-altitude surveillance. It comes after the nation scrambled fighter jets to shoot down a Chinese balloon as it drifted through North American airspace last year.

Modern balloons can use artificial intelligence to predict and ride wind currents while operating at altitudes around 18 kilometres, or even higher, in Earth’s stratosphere for commercial and military purposes. Those heights make them hard to…