sky reference

例句：

1. 1.The astronaut used the sky reference to determine their position in space.
   宇航员使用天空参考点来确定他们在太空中的位置。
2. 2.The scientist conducted an experiment using the sky reference to study the movement of stars.
   科学家通过使用天空参考点来研究星星的运动。
3. 3.The astronaut was able to communicate with Earth using the sky reference, which helped them navigate back to their launch site.
   宇航员能够使用天空参考点与地球进行通信，这帮助他们导航返回发射场。