The first Apollo flight to leave Earth's atmosphere and circle the Moon was Apollo 8.

The astronauts on that mission were:

* Frank Borman (Commander)

* James Lovell (Command Module Pilot)

* William Anders (Lunar Module Pilot)

They launched on December 21, 1968, and orbited the Moon 10 times before returning to Earth on December 27th. This mission was a major milestone in the space race, as it proved that humans could travel to the Moon and survive the harsh conditions of space.