PHILADELPHIA (FOX 29) - Saturday marks the 50th anniversary of a seminal moment in space exploration.
On May 18, 1969, the Apollo 10 mission launched from Kennedy Space Center in Merrit Island, Fla for the fourth crewed mission in United States history.
Aboard the 49,000 ton Saturn V rocket, Astronauts Thomas Stafford, John Young and Eugene Cernan sought out to orbit the moon for the second time in American space travel.
Often thought of as a dry run for the moon landing, NASA says Apollo 10 helped "sort out the unknowns to make the moon landing possible."
In July of 1969 - just two months after Apollo 10 - the Apollo 11 mission successfully put Neil Armstrong, Buzz Aldrin and Michael Collins on the surface of the moon.