弹道学

例句：

1. 1. The physicist's research on the trajectory of spacecraft is a key part of his work.
   这位物理学家对航天器轨迹的研究是他工作的关键部分。
2. 2. The trajectory of the project will be closely monitored to ensure its success.
   该项目的轨迹将受到密切监控以确保其成功。
3. 3. The trajectory of the missile was carefully planned to avoid collision with other spacecraft.
   导弹的飞行轨迹被精心规划以避免与其他航天器相撞。