May 18, 1969 – launch of Apollo 10

The fourth manned mission in the Apollo program was Apollo 10, launching on May 18, 1969. The Apollo 10 crew was the second U.S. crew to orbit the Moon. This mission tested the lunar module in orbit.

Crew: Gene Cernan, Tom Stafford and John Young (L/R)
Image credit: NASA

Wikipedia says:

“The module came to within 8.4 nautical miles (15.6 km) of the lunar surface during practice maneuvers. According to the 2001 Guinness World Records Apollo 10 has the record for the highest speed attained by a manned vehicle: 39,897 km/h (11.08 km/s or 24,791 mph). The speed record was set during the return from the Moon on 26 May 1969.”

Image credit: NASA

See the Apollo 10 press kit (pdf – 4.6mb)