Apollo 13

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Like all other Apollo spacecraft, Apollo 13 was made up of three main units the Service Module, Command Module, and Lunar Module. All of which played a specific role in the Apollo 13 Mission but, as a result of the explosion, those roles had to be altered. The Service Module was supposed to supply the crew with oxygen, water, and power but much of these necessities were lost due to the explosion and the Service Module was nonfunctional. The Command Module, also called Odyssey, also supplied oxygen and power but it served another purpose which was reentry so in order for that function to take place the crew had to conserve power by shutting off Odyssey. The Lunar Module, also called Aquarius, was originally to be used when the crew landed on the moon. However, this was no longer a mission to land on the moon this was a mission to return the crew to earth safely. Aquarius was now serving as an emergency lifeboat.

Due to the fact that they were no longer going to the moon, the spacecraft was in a “free-return” trajectory meaning they were to use the moon’s gravity to loop around the moon and start heading in Earth’s direction. In order for this to happen they had to power up the Lunar Module and power down the Command Module before the Command and Service Module (CSM) batteries died out. They also had a problem with the Lunar Module. The Lunar Module was designed for a 45-hour lifetime. The crew had to stretch this to a 90 hour lifetime.