1970

Apollo 13

The successful moon missions—Apollo 11, 12, 14, 15, 16, and 17—are magnificent triumphs of engineering. The mission architecture, the design process, the technology created, the execution, the pace of development, the reliability of the equipment … it all speaks volumes about the engineers involved in this massive undertaking.

And then there was Apollo 13, in 1970, which was a different sort of engineering achievement. The problem on Apollo 13 was that an oxygen tank exploded due to an electrical problem inside the tank. The explosion eliminated the oxygen supply for the command module, meaning that the spacecraft had no oxygen for breathing or for power production with its fuel cells.

This scenario created an impressive, immediate challenge for engineers on the ground. Would they be able to use the equipment available and quickly put together a plan to bring the astronauts home safely? Amazingly, despite all the problems that appeared during the ordeal, engineers were able to use the LEM (Lunar Excursion Module) as a lifeboat and get everyone home.

The command module’s only source of power was a battery system. So the astronauts shut down the command module and moved into the LEM to save the batteries. The LEM, unfortunately, was not designed to support three astronauts for such a long period of time, meaning that CO2 concentration would build up to deadly levels. The astronauts were able to rig a way to use command module scrubbers in the LEM. The LEM’s descent engine was also used several times to create the correct trajectory around the moon and back to Earth.

And then the final problem—the astronauts had to return to the command module and reactivate it from its shutdown state, running it on battery power through the landing. Running on battery power during reentry was normal, but the reactivation process was not. Engineers, astronauts, and flight controllers found a sequence that would allow reactivation with the available power. Then the return to Earth and splashdown proceeded normally.

It was an amazing example of on-the-fly problem solving, engineering, and system re-appropriation. And all of the astronauts returned safely. Rather than being one of the world’s bigger engineering disasters, it was a triumph.

SEE ALSO Apollo 1 (1967), Lunar Landing (1969), Lithium Ion Battery (1991).

Deke Slayton (checked jacket) shows the adapter devised to make use of square Command Module lithium hydroxide canisters to remove excess carbon dioxide from the Apollo 13 LM cabin.