free flight trajectory

例句：

1. 1. The free flight trajectoryof the aircraft is crucial for navigation.
   飞机的自由飞行轨迹对于导航至关重要。
2. 2. The researchteam developed a new algorithm to optimize thefree flight trajectory of drones.
   研究团队开发了一种新的算法，以优化无人机的自由飞行轨迹。
3. 3. The free flight trajectory ofthe spacecraft was carefully planned to ensuresafe landing.
   太空船的自由飞行轨迹被仔细规划，以确保安全着陆。