Conversation so far:
what year did the us land on the moon
The United States' Apollo 11 was the first crewed mission to land on the Moon, on 20 July 1969.
how many apollo missions were successful
Six of the Apollo missions landed humans on the Moon and brought them safely back to Earth
which apollo missions were successful
Apollos 11, 12, 14, 15, 16, and 17 succeeded in landing on the Moon

Question: how many astronauts made it
Self-contained rewrite: how many us astronauts made it to the moon