The highest speed ever achieved by a man

This is the crew of Apollo 10, which holds the record for the highest speed reached by a man (actually, three men), showing a peak of 39,897 km/h (24,791 mph). The Saturn V rocket that set the record is the record holder for the fastest vehicle of all time (by vehicle, we mean a human transporter that actually carried men).  Apollo 10 crew also has a fun first : the first insult launched from space.

The record was held May 26, 1969, during the back trip to Earth. The aim of this Apollo 10 mission was to fly over the moon (it was the second flight to this destination, in history) in order to prepare procedures and equipment for Neil Armstrong and his colleagues, so that they can later be the first men to walk on the moon

Still, Apollo 10 holds the primacy of an exceptional event: the first expletive launched from space (and heard on Earth). Indeed, during a bad maneuver, Eugene Cernan could not help dropping a "sonofubitch" while the cabin's microphone unvoluntarily remained open, allowing the ground control team to share this particular moment of space's history. 

The three astronauts, who traveled fastest in the history of mankind, were Eugene Cernan, Thomas Stafford and John W Young.