The Apollo 13 CO2 Crisis: The Mailbox Scrubber Fix |…

The CO2 Crisis

During the ill-fated Apollo 13 mission, a critical event occurred that threatened the lives of astronauts Jim Lovell, Fred Haise, and Jack Swigert. A ruptured oxygen tank in the Service Module led to a loss of power, forcing the crew into the Lunar Module (LM) for safety. However, this cramped environment quickly became dangerous as carbon dioxide levels rose due to the saturation of lithium hydroxide (LiOH) canisters designed to absorb CO2.

The LM's LiOH canisters were limited in number and capacity, making it imperative that a solution be found to extend their functionality or find an alternative method to remove CO2 from the cabin atmosphere.

The Mailbox Scrubber Fix

In a remarkable display of ingenuity, astronauts and mission control engineers devised a makeshift adapter using materials available on board. The 'mailbox' scrubber was created by modifying an empty mail container (mailbox) to fit the Command Module's (CM) CO2 canisters. This adapter used CM canisters that had not been used in the LM.

The mailbox design involved cutting and reshaping the mail container to fit the CM's canister, creating a seal with tape and Velcro to ensure proper functionality.

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Engineering Principles

The solution hinged on understanding the principles of gas adsorption. LiOH reacts chemically with CO2 to form lithium carbonate (Li2CO3) and water, effectively removing CO2 from the cabin atmosphere. The key was to repurpose CM canisters that had not been used in the LM, as they were designed for a longer duration and thus had more capacity.

The mailbox adapter ensured that these canisters could be utilized in the cramped space of the LM by adapting their shape and ensuring proper sealing.

Why It Matters

This crisis highlighted the importance of contingency planning and resourcefulness in space exploration. The successful implementation of the mailbox scrubber demonstrated that even with limited resources, creative solutions can be found to overcome seemingly insurmountable challenges.

The story of Apollo 13 has become a symbol of human resilience and problem-solving under extreme conditions.

Frequently asked questions

How did the astronauts survive without the mailbox scrubber?

Without the mailbox scrubber, the astronauts would have faced suffocation due to rising CO2 levels. The LM's canisters were limited and soon saturated, making it necessary to repurpose CM canisters in a makeshift adapter.

What materials did they use for the mailbox scrubber?

The astronauts used an empty mail container (mailbox) from the LM, cutting and reshaping it to fit the Command Module's CO2 canisters. They sealed the adapter with tape and Velcro.

Why was it important to use CM canisters in the LM?

CM canisters were designed for a longer duration and thus had more capacity, making them better suited for repurposing in the cramped space of the LM compared to the already saturated LM canisters.

What was the outcome of the Apollo 13 mission after the mailbox scrubber fix?

The successful implementation of the mailbox scrubber allowed the crew to maintain breathable air levels and safely return to Earth, though the mission was ultimately aborted due to the loss of power in the Service Module.

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