In addition, a vent for liquid oxygen would not close at first and required several recyclings before it would shut properly.The launch, itself, went according to plan, although it went off an hour late.Immediately after attempting to follow flight control's last order to stir the cryo tanks, astronaut Jack Swigert heard a loud bang and felt a shudder throughout the ship.
Luckily, it ended well, but it took every bit of brainpower among the astronauts and the mission controllers to make it work. Just days before liftoff, astronaut Ken Mattingly was replaced by Jack Swigert when Mattingly was exposed to German measles.
There were also some technical issues that should have raised eyebrows.
In case of complete engine loss, this meant the craft would slingshot around the moon and be on course for a return to Earth.
After completing the broadcast, flight control sent another message, "13, we got one more item for you when you get a chance. In addition, have a shaft and trunnion, for a look at the Comet Bennett if you need it." Moments later, disaster struck.
There were two problems to be solved to keep the astronauts alive: first, getting the ship and crew on the fastest route home and second, conserving consumables, power, oxygen, and water.
However, sometimes one component interfered with the other.Then, the third stage engine ired for an extra nine seconds during its orbital insertion burn.Fortunately, this all resulted in a mere 1.2 feet per second greater speed than planned.At first, they thought it was a practical joke previously played by Fred Haise. Seeing the expression on Jack Swigert’s face, Jim Lovell knew immediately that there was a real problem and hurried into the CSM to join his lunar module pilot. Alarms were going off as voltage levels of the main power supplies were dropping rapidly.If power was completely lost, the ship had a battery backup, which would last for about ten hours. Looking out a port, the astronauts saw something that gave them another concern."We are, we are venting something out the, into the ahh, into space." A momentary hush fell over the Flight Control Center in Houston as this new information sank in.Then, a flurry of activity began as everybody conferred. As several suggestions for correcting the dropping voltage were raised and tried unsuccessfully, it quickly became apparent that the electrical system could not be saved.Apollo 13 was a mission that tested NASA and its astronauts to the hilt.It was the thirtheenth scheduled lunar space exploration mission, scheduled for liftoff at the thirtheenth minute after the thirteenth hour.The resulting impact was to be measured by equipment left behind by Apollo 12.The command service and lunar modules were then on "free return" trajectory.