Yes, I know it to be TRUE. Look up the details of the Apollo Command Module, it is all explained there. It was a special sextant that was built into the ship. It had three lines of sight: One for the the sun. one for a guide star, and another for the leading edge of the moon. (Normal sextants have two lines of sight.)
The gyroscope-based navigation system was subject to drift, even though it was the best they could build in those days. This drift was significant enough to fail the landing. Sextant sightings were used to reset the IMU platforms for absolute actual positioning relative to the moon, earth, and sun.
This was all published in the 1960s. See the Apollo astronaut site his sextant.
See the pretty sextant:
Lets get a good look:
Are you capable of even a lame level of research?