Apollo 13: A Failed Moon Mission But Safe Return

In the history of Apollo Program, the Apollo 13 mission was the only maned moon mission that reached close to the moon but could not touch down its surface. Actually, there was a problem of oxygen leakage in the combustion chamber of the spacecraft that was noticed when the spaceship was closing to the moon.
“Houston, we've had a problem” is the now famous phrase radioed from Apollo 13 to Mission Control upon the catastrophic explosion that dramatically changed the mission. Since then the NASA has learnt a lot from this failure and improved its techniques for moon missions in upcoming Apollo missions. The Apollo 13 mission has become known as “a successful failure” that saw the safe return of its crew Commander James (Jim) Lovell Jr., Command Module Pilot John Swigert Jr. and Lunar Module Pilot Fred Haise Jr.