translation.en: Since one of the things that was most likely to kill the Loon project was whether we could guide the balloons through the sky, one of our most important experiments was putting a balloon inside a balloon.
translation.zh: 因为这个项目会不会被扼杀 很大程度上取决于 一个重要的技术， 就是如何在空中控制气球。 其中一个重要的实验就是把气球放在气球中，