Like A Movie . . .

Jules Verne, From the Earth to the Moon Direct in Ninety-seven Hours and Twenty Minutes, and a Trip around it. Trans. by Louis Mercier and Eleanor King [De la terre à la lune], 1874

It seems like the perfect plotline for a superhero movie—three men stranded in a malfunctioning rocket floating through outer space, a spandex-clad figure to come to the rescue. But when, on the 13th of April 1970, during the 13th Apollo mission, astronauts James Lovell, Fred Haise, and John "Jack" Swigert were confronted with such a circumstance, there was no caped crusader to save them. Instead, Lovell, Haise, Swigert and a group of determined men and women were called upon to use only the very human strength of their own brains to avert disaster and return safely to Earth. Their story has become a legend, and remains one of the greatest examples of the power of the human mind.Superstition is not something that factors into the planning of manned spaceflight. Thus, in spite of the reoccurrences of the ominous number “13,” NASA launched their Saturn-V rocket on a mission destined to explore the Fra Mauro area of the moon. Problems with the mission began to develop days before the scheduled launch when the back-up Lunar Module (LM) pilot, Charlie Dukes, exposed the crew to German measles. NASA doctors feared that Thomas Kenneth “Ken” Mattingly, the planned Command Module (CM) pilot had contracted the illness and he was removed from the mission. Mattingly was replaced by Jack Swigert, a bachelor rookie with a reputation for being a playboy. It was an unsettling decision for an established crew that had learned to interpret each other’s inflections and body language.

The first equipment problem occurred just 5 minutes after lift-off when one of the massive Saturn V’s five main engines shut down early, forcing the remaining engines to burn for and additional 34 seconds, and delayed the spacecraft’s orbit by 9 seconds. Given the importance of a precise schedule during a rocket launch, the fact that it took an additional 9 seconds to get Apollo 13 into orbit was an immediate cause for concern. Any change in the schedule or procedures of a mission could have dramatic results. In this case, crisis seemed to have been averted, and the spacecraft made it safely beyond orbit and on its way to the moon.

Apollo 13 was to be the 3rd lunar mission, and by then the public had lost interest in the program, feeling it had become “routine.” At just under 56 hours into the mission the crew finished a 49-minute TV broadcast, unaware that none of the networks had aired their transmission. Lovell signed off wishing everyone a “pleasant evening” and saying he looked forward to the same. At that time Mission Control requested a routine procedure, and Swigert complied with the command to stir the liquid hydrogen and liquid oxygen tanks to generate a more accurate reading of their storage quantity. These tanks were the source of power for the Service Module (SM) that provided propulsion for the engine, electricity from the fuel cells, and drinking water (which is a handy by-product of the fuel cells) used during a mission. Unbeknown to anyone there was a damaged piece of insulation on the wires of the stirring motors, which caused a short in Oxygen tank No. 2 and ignited the insulation. A fire escalated, and at 55 hours and 55 minutes into the mission, the crew heard and felt a deep rumble as Oxygen tank No. 2 exploded. The force of the explosion was powerful enough to damage Oxygen tank No. 1, and it began fail as well. 200,000 miles from Earth, astronauts Lovell, Haise and Swigert found themselves without electricity, light, or water, and with the last of the oxygen in tank No. 1 rapidly leaking into space. It was Jack Swigert who uttered the now famous line when he announced to Mission Control, “Houston, we’ve had a problem.”

Here, of course, would be Superman’s cue to thrust his fist towards the sky and fly into the reaches beyond to rescue our stranded crew and return them safely to our oxygen rich planet. But this was not a comic book or a movie, this was happening in real life, and the idea of a rescue fell into the hands of an endangered crew and a stunned but determined group of ground controllers. Lovell, Haise and Swigert were running the CM on battery power, having run out of the oxygen necessary to power the SM fuel cells, which would in turn power their electricity and water supplies. But the batteries in the CM would not last forever, and without battery power there would be no hope of ever returning the men to Earth.

The Lunar Module (LM) had a good supply of oxygen, so Mission Control ordered the men to evacuate the CM and seal themselves into the LM. The CM was powered down, and the LM became a “lifeboat” for the three men. By then NASA knew that there was no hope of landing on the moon, and the goal of the mission was simply to return the men safely to Earth. Moving to the LM was a quick fix designed to keep them alive and save the limited available power in the CM while Mission Control considered their options and devised a plan to bring the men home. It was a daunting task, as a whole new set of procedures had to be developed and tested, including devising a new flight path and a way to execute it without the use of computers.

Had Apollo 13 stayed in a free return trajectory following launch, it would have eventually circled the moon once and returned to Earth, and it would therefore not have been necessary to fire the engines again. But they had planned for a lunar landing, and had altered their course accordingly by putting themselves in a lunar orbit insertion trajectory. Were they to maintain their planned course, the astronauts would have been trapped in lunar orbit forever. So Mission Control’s first challenge would be to determine how, where, and when to put the spacecraft back on the free return trajectory. Controllers believed the engines in the SM were damaged beyond use, so the challenge of how to alter the course was their first concern. After much discussion they decided to use the descent propulsion system in the LM for a 35 second burn that would put the spacecraft into a free return trajectory designed to “sling-shot” the craft around the moon.

Power was a major issue and Mission Control immediately began developing a way to recharge the CM batteries with power from the LM batteries. Meanwhile the crew was struggling to stay alive. Water and electricity were scarce consumables in the LM, so the system was kept at minimum power, and the crew was instructed to reduce their daily water intake to a mere 6 ounces. Lovell described the temperature in the LM as that of a “meat locker.” Haise had come down with the flu, and all three of the men were suffering from exhaustion and dehydration. They would soon face another threat when it was discovered that the carbon dioxide levels in the LM were rising to dangerous levels.

The spacecraft was equipped with lithium hydroxide canisters that were designed to remove the carbon dioxide in the air. But the canisters in the LM were designed to support 2 men for 2 days, and after a day and a half of supporting 3 men they had absorbed as much carbon dioxide as they could handle, and were full. Mission Control needed to develop a way to use the canisters from the CM to remove the carbon dioxide in the LM. Unfortunately the canisters on board the CM were incompatible with the LM. It was a challenge that could be a metaphor for the whole mission: how to get the square canisters from the CM to fit into the round openings of the canister-sockets on the LM. Using only the plastic bags, cardboard and duck tape carried on a mission, ground controllers invented a device that solved the problem, and would be nicknamed “the mailbox.” No super-human strength was used, just the amazing brainpower of NASA mission controllers necessary to determine how to fit a square peg into a round hole.

Another great example of human ability happened when the crew returned from the far side of the Moon.   Controllers had transferred the CM navigational platform alignment to the LM but they were struggling to work it successfully. Ordinarily a device called the Alignment Optical Telescope (AOT) allows the crew to find a suitable navigation star, which is then verified by an onboard computer. But the explosion had caused so much small, shiny debris that the crew was unable to locate real stars. Mission Control developed a tricky procedure that would use the sun as the alignment star. Thus, when Lovell rotated the spacecraft to the attitude determined by the ground controllers, looked through the AOT and found the sun was just where it was predicted, Mission Control and the Apollo 13 crew knew that they had accomplished one of the most daring feats of the mission, and that the chance of a safe return to Earth was truly possible. With that, the crew executed a 5-minute burn of the LM descent engines, speeding up the spacecraft and cutting more time off of the mission. The men were flying without computers, without a tested flight plan or operations manual, and having to use the Sun, Moon and Earth to navigate their way back onto the correct trajectory.

The final challenge faced by Mission Control was to develop a procedure for powering up the CM.   Normally the CM would have been powered up on the ground prior to launch, using the all the electricity it needed to reach operational status. However, now this same feat had to be performed using nothing but the remaining power in the batteries from the damaged SM. The freezing temperatures had caused widespread condensation across the control panels and there was concern that the water would cause another short and fire. During the 3 days that the Apollo 13 spacecraft was orbiting around the Moon the men and women of Mission Control devised a new set of procedures for the re-powering of the CM. This was a process that usually took many months, and the fact that they were able to do it in 3 days with the added pressure and fears of the ill-fated mission overshadowing them is just another statement about the strength of the mind of the individual. With the crew back in the CM for the first time since the explosion, Mission Control waited to see how the new procedures would play out. One-by-one the systems came back on without problem, and soon the crew and controllers knew that they were hours from seeing the men reenter the Earth’s atmosphere.

Four hours before landing the crew disconnected the SM from the CM. This was the first time they were able to see the damage caused by the explosion. Lovell reported back to Houston that an entire panel was missing. The magnitude of the explosion—and the disaster that they had managed to avoid—was finally clear. One hour before reentry they jettisoned the LM, with Mission Control radioing, “farewell . . . we thank you” as she drifted away.

The final heart-stopping moment of the mission came just as the CM reentered the Earth’s atmosphere.   The massive heat generated during reentry caused a radio blackout and the crew and Mission Control were unable to communicate. Normally a radio blackout would last for about 4 minutes, but the lengthy reentry time extended the blackout time to 6 minutes. Finally Mission Control heard Swigert’s voice over the radio, and the craft made a safe splashdown in the Pacific Ocean. Lovell, Haise and Swigert were home.

NASA deemed the mission a “successful failure” because they had been able to rescue the crew, but not able to land on the moon. While the public had shown no interest in the mission before the explosion, the story had become and international obsession during the rescue. The men were greeted with ticker-tape parades, and were awarded the Presidential Medal of Freedom by President Nixon. Their story would go on to be the basis of numerous best-selling books and movies, including the Oscar-nominated Apollo 13 movie that starred Tom Hanks as Jim Lovell, Bill Paxton as Fred Haise, Kevin Bacon as Jack Swigert and was directed by Ron Howard. To this day the mission is remembered every year with lectures and TV programs that discuss the great moment in history.

While it is most often thought of as an example of adventure in space, the truly remarkable part of the Apollo 13 story is found in the group of determined individuals who were equipped with no more than mind and spirit and were able to use those tools to conquer a monumental challenge. The heroes of Apollo 13 weren’t the cape-wearing superheroes of the comics. Rather, these heroes wore ties and pocket protectors, and were engineers, scientists, physicists, and mathematicians, who used their collective brainpower to solve the worst crisis NASA had faced, and successfully brought the crew of Apollo 13 home. It is a great—and very human—lesson.

—Carrie Carter 

Apollo 13: the NASA mission reports, compiled from the NASA archives & edited by Robert Godwin. 2000.

Lost moon: the perilous voyage of Apollo 13, Jim Lovell & Jeffrey Kluger. c. 1994.

Apollo 13 mission. Hearing, Ninety-first Congress, second session. April 24, 1970.

Apollo 13: "Houston, we've got a problem." 1970.