Liftoff of Apollo 13!
April 11, 2022
Liftoff of Apollo 13! "The clock is running."
Apollo 13 lifted off at 2:13 p.m. EDT on April 11, 1970. The original goal of this mission was to land in the hilly upland region of the Moon, called the Fra Mauro highlands.
This was supposed to be the third mission to land on the Moon. The original crew members for Apollo 13 were astronauts Jim Lovell, Ken Mattingly, and Fred Haise. Ken Mattingly was inadvertently exposed to the German measles in the days before the launch, necessitating his replacement. This meant that Jack Swigert became the Command Module Pilot just three days before liftoff.
The crew switch at the last minute wasn’t the only unexpected event for this mission. There was a severe oscillation issue with the center engine on the S-II, the second stage of the Saturn V.
Launch hiccups and crew changes were the least of the problems during Apollo 13. Most unexpected was the explosion in oxygen tank #2. This event nearly cost the crew their lives and prevented them from touching down on the Moon.
"Houston, we've had a problem."- Jim Lovell.
At 55 hours, 53 minutes into the flight Command Module Pilot Jack Swigert stirred the cryogenic liquid oxygen tanks, one of which was the defective tank #2. In the seconds after this switch was flipped, the Teflon coating that insulated the wires on this system caught fire after being sparked by the very wires it was insulating.
The resulting fire weakened the tank and the pressure resulting from this conflagration caused tank #2 to explode. This detonation damaged the other oxygen tank and other parts inside this section of the service module. With how the CSM was designed at this point in the Apollo program, there were no backup oxygen tanks in other parts of the CSM. Losing both oxygen tanks was a catastrophic failure that necessitated canceling the Moon landing.
NASA worked tirelessly to bring the crew of Apollo 13 home. Ground controllers, engineers, contractors, and astronauts came up with ingenious solutions, navigation corrections, and procedures that brought the crew back home to Earth.
Apollo 13 is considered a "successful failure" because of the work that was done to bring the crew home safely.
Captions: NASA mission transcripts and Cosmosphere volunteer, John Mulnix.