Star trackers do exist and have been used on spacecraft for decades. But unfortunately, looking at the stars can only tell you your orientation in space, not yo

Star trackers do exist and have been used on spacecraft for decades. But unfortunately, looking at the stars can only tell you your orientation in space, not your position. (At least, not to any remotely useful accuracy; you need to travel a huge distance to get a measurable parallax.) Celestial navigation works on the Earth's surface (or the Moon's surface), because being able to determine the orientation of the local horizon (or zenith) is equivalent to determining your latitude and longitude. But that doesn't work for a spacecraft that doesn't have a horizon reference. Of course, if you're orbiting the moon and you can accurately observe the directions to landmarks such as mountains and craters, you can fix your position relative to them. But that's not really what you'd call "celestial navigation".