So while military aircraft conduct high speed flights over water and at high altitudes, supersonic commercial flights seemed like a brief and failed experiment.

因此，当军用飞机在水上和高空进行高速飞行时，超音速商业飞行似乎是一个短暂而失败的实验。

The drones used in Tuesday's launch are about 2 meters wide, with a maximum payload of 10 kilograms and a flight speed of 50 km per hour.

8月13日发布的无人机有2米宽，最高载货量为10千克，飞行速度达50千米/时。