Joe is Vanguard's global chief economist and head of Vanguard Investment Strategy Group. He's also a member of the senior portfolio management team in Vanguard Fixed Income Group.
Apollo missions took about three days to reach the moon. But the quickest trip to the moon was the New Horizons probe, which zipped past the moon in just 8 hours 35 minutes on its way to Pluto. However, the spacecraft didn't even slow down or approach lunar orbit. Tidal forces.
Apollo 8 took 69 hours, 8 minutes to enter orbit around the moon. Apollo 11, which placed the first humans on the moon, took 75 hours and 56 minutes to enter orbit around the moon. Long before they entered orbit, however, both spacecraft entered the moon's sphere of influence, a region 33,823 nautical miles (62,630 km) from the moon. For Apollo 11, this occurred after 61 hours and 56 minutes, while for Apollo 8 it took only 55 hours 40 minutes.