Apollo 13 AMA Recap

Posted on Tue, April 14, 2020

On Monday, April 13, the 50th anniversary of "Houston, we've had a problem," the Museum's Apollo curator Teasel Muir-Harmony participated in a Reddit Ask Me Anything (AMA) on r/space with NASA Chief Historian Bill Barry and Apollo in Real Time creator and NASA data visualization engineer Ben Feist.

We've put some of our favorite questions from the Reddit AMA below. Check out the full AMA.

How did the events of Apollo 13 change the way NASA developed equipment for space?

After an investigation into the Apollo 13 accident, NASA modified the spacecraft electrical system significantly for the next Apollo mission. The earlier cryogenic oxygen tanks contained two fans, and these were removed, the heating element was modified, heater thermal switches were removed, and all wiring went from being Teflon-insulated to magnesium oxide-insulated and sheathed with stainless steel. An additional cryogenic tank was installed as well as an isolation valve which could prevent the loss of oxygen from tank 3 if tanks 1 and 2 were damaged. An auxiliary battery was added to the aft bulkhead of the service module. They also added a contingency water storage system for drinking water in case the water in the regular potable tank became undrinkable. There were also changes made to displays and controls, ascent and descent batteries, the addition of a pressure transducer in the helium tanks to provide redundancy for monitoring leaks, and numerous other updates. It’s worth mentioning that NASA improved and updated hardware throughout the Apollo program, learning from each mission. Lessons from Apollo 8 contributed to some of the essential fixes on Apollo 13, for instance.

         - Teasel Muir-Harmony, National Air and Space Museum curator of Apollo spacecraft


What was the most tense moment from the perspective of Mission Control, the one where it seemed most likely the mission would end in disaster?

That's a tough one. I think probably the moment when Jim Lovell reported seeing something venting out into space. You can hear that exact moment here. When mission control heard this, the whole situation changed from probably being an instrumentation problem to being a serious physical problem with the spacecraft, and at that time nobody knew whether there would be a way to get home safely.

         - Ben Feist, creator of Apollo in Real Time


I'm curious what the time frame was from the oxygen tank rupture to the time a solution (or perhaps rather a work around) was found and implemented. 

Listening to the accident play out at Mission Control using the Apollo 13 In Real Time site, I was stunned to realize that it was almost 15 minutes between the explosion and Lovell seeing the oxygen venting. Things played out a lot more slowly in real time than you are used seeing in the movie. It is hard to give a firm answer to your question because new problems kept appearing, but generally speaking the basic plan was worked out in a few hours.

         - Bill Barry, NASA Chief Historian


Was there ever any discussion of putting these three disappointed souls back into the rotation for another, later mission?

Commander Jim Lovell decided before Apollo 13 that this would be his last mission. He had already flown two Gemini missions and Apollo 8 in 1968. He wanted to make sure other astronauts had the opportunity to fly. After Apollo 13, when he was asked your question at a press conference, he saw his wife Marilyn at the back of the room give a thumbs-down response, and he said he was not planning on flying again.

         - Teasel Muir-Harmony, curator of Apollo spacecraft