The Safe Return Home
The two docked spacecraft flew with the service module’s engine cone in the direction of travel. This allowed the crew to use the lunar module’s descent engine for course corrections. Controllers determined that the explosion could have damaged the service module’s core engine.
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As the Earth grew larger in the windows, Swigert returned to Odyssey to begin powering up the frozen craft. Once ready, the crew loaded into the command module to separate the lunar lander safely away. They were 90 minutes away from landing.
“We pressurized the tunnel between the two vehicles,” Haise continued. “So when we separated the lunar module, and it was quite a jolt, it actually projected (Aquarius) away from us out to the side.”
Odyssey reentered the Earth’s atmosphere and successfully splashed down in the southern Pacific Ocean on 17 April 1970.
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Apollo 13 Accident Investigation
According to NASA, Apollo 13’s No. 2 oxygen tank, serial number 10024X-TA0009, was first installed into Apollo 10’s service module. It was then removed and damaged in the process. The O2 tank was repaired and tested before it was installed in the service module for Odyssey.
In addition, the voltage to the heaters inside the oxygen tanks had been upgraded from 28 to 65 volts DC. The thermostatic switches, however, were not upgraded.
During the Apollo 13 countdown test with the Saturn 5 in March 1970, heaters inside the oxygen tank were on for a long time. This caused the nearby wiring to reach temperatures near 1000 degrees F, causing the wiring’s teflon insulation to degrade.
NASA’s investigation board noted the thermostatic switches had begun to open, but were welded shut by the nearly eight hours of high heat during the countdown test. The investigation board then said, “The tank was a potential bomb the next time it was filled with oxygen. That bomb exploded on April 13, 1970.”