Last month marked the fiftieth anniversary of Apollo 13, which launched on 11th April 1970, intended as the third manned mission to land on the Moon. Its commander, Jim Lovell, would be the first man to fly in space four times and the first to go to the Moon twice. Accompanying him were rookie astronauts Jack Swigert and Fred Haise; Swigert was a last-minute replacement for the original command module pilot, Ken Mattingly, who had been grounded after being exposed to German measles. After two successful lunar landings in 1969, public interest in the Apollo program had diminished all too quickly, and a TV broadcast by the crew did not appear on any networks.
That would abruptly change 55 hours and 54 minutes into the flight, when Apollo 13 was 210,000 miles from Earth. A simple maintenance procedure – turning on a fan to stir the contents of the service module’s Oxygen Tank No. 2 – caused the tank to explode, crippling the command and service module and depriving the spacecraft of both oxygen and electricity. Now fighting for their lives, the astronauts powered down the command module and moved into the lunar module, using its engine to put them on a trajectory to loop around the Moon and return to Earth. For four days, through the efforts and improvisation of thousands of people on the ground, the resources of the lunar module – intended to support two men for two days – were stretched to their limit. And in the end, it all worked out: on 17th April, Lovell, Swigert and Haise splashed down in their command module, at the end of what would become known as “a successful failure”.
Apollo 13 remains one of the most enduring space-related stories in history; indeed, twenty-five years later, it became the subject of a successful film, which remains my second-favourite film of all time. It’s simply a great story that lends itself very well to a structured re-telling: starting out with a journey viewed by the public as routine, and the number 13 providing a little ominous foreshadowing in hindsight, it leads into stirring themes of survival and overcoming adversity through spectacular ingenuity and team effort. The film, which is largely faithful to the real events, contains many lines which can be applied to problem-solving situations, such as “Let’s work the problem, people – let’s not make things worse by guessing” and “I don’t care about what anything was designed to do – I care about what it can do!”
A lot of improvisation based on engineering knowledge went into bringing Lovell, Swigert and Haise back to Earth alive, as well as the skills, experience and cool heads of the astronauts themselves. It’s interesting to note, however, that some of the ideas applied had been experimented with well before Apollo 13, not necessarily with this exact scenario in mind, but just in case – as detailed in this article,“Apollo 13, We Have A Solution”. There was some useful information that had only been acquired by chance: for example, in his lecture in Pontefract in 2015, Jim Lovell mentioned that the best prior indication that the command module’s guidance unit would still work after a period of cold exposure, had come from one such unit still working after an engineer accidentally left it in his car during a freezing night.
I also find it interesting how the actual oxygen tank explosion itself was caused by a series of small and apparently insignificant errors all coming together to create a serious problem. First, Oxygen Tank No. 2 was dropped a short distance before it was installed in the service module, causing just enough of a shift in the tubing that when oxygen was later pumped into the tank for a test, it couldn’t be drained away again. Second, a thermostat inside the tank was out of date, built to operate at a lower voltage than the rest of the Apollo spacecraft. When the tank was heated to boil the oxygen inside away following the test, the thermostat should have kept the temperature from rising above 80 degrees Fahrenheit; instead, the high voltage caused it to fail, and the unchecked heaters brought the temperature up to 1000 degrees Fahrenheit. Third, the temperature gauge for the tank only went up to 85 degrees, so nobody knew what was happening at the time. Teflon insulation covering electrical wires inside the tank was damaged by the heating, leading to the explosion on the actual flight. It was a perfect demonstration of why Chris Hadfield’s book, An Astronaut’s Guide to Life on Earth, contains a chapter called “Sweat the Small Stuff”.
If you would like to learn more, I strongly recommend the book Apollo 13 (formerly titled Lost Moon) by Jim Lovell and Jeffrey Kluger, which provides plenty of details and extra moments of tension that the film had to leave out. The second series of the BBC podcast 13 Minutes to the Moon has also been covering Apollo 13, including interviews with the people involved.