Fate intervened just days before launch. Mattingly was exposed to German measles (rubella) via a friend, and while he showed no symptoms, NASA’s strict quarantine protocols demanded he be removed from the crew to protect the others. In a decision that would later seem prophetic, Mattingly was replaced by his backup, John L. “Jack” Swigert Jr. Swigert was a capable pilot, but he had only 48 hours to integrate into a tightly-knit team. The chemistry was slightly off; Lovell later recalled a moment of tension when Swigert used the wrong pronoun, saying “my” flight plan instead of “our.” That minor friction would soon dissolve into a life-or-death partnership. The first two days of the mission were unremarkable. The crew performed a trans-lunar injection burn, slingshotting them toward the Moon. On the evening of April 13—ironically, the 13th—the crew had just completed a television broadcast, showing the American public a somewhat sleepy view inside the spacecraft. Lovell signed off with a casual, “This is the crew of Apollo 13. Good night.”
The cold was unbearable. To save power, they shut off all non-essential systems. The temperature inside the LM dropped to near freezing—about 38°F (3°C). Water condensed on every surface. The men developed urinary tract infections. Haise ran a fever of 104°F. They slept in shifts, shivering violently, their breath fogging the tiny windows. The Moon, once their destination, now became their slingshot. They looped around the far side at a distance of 254 kilometers (158 miles)—closer than any lunar module had ever come. During the 25 minutes of radio blackout behind the Moon, the crew was utterly alone. Lovell later wrote that he felt the silence “like a physical weight.” When they emerged, the critical burn to accelerate their return to Earth had to be performed with pinpoint accuracy. Apollo 13
Onboard, the crew felt a loud “bang” and a shudder that ran through the entire spacecraft. Warning lights exploded across the instrument panel. Swigert, his voice tight but professional, radioed the now-immortal words: “Okay, Houston, we’ve had a problem here.” (The 1995 film famously misquoted it as “Houston, we have a problem.”) Lovell quickly confirmed, “Houston, we’ve had a problem.” In Mission Control in Houston, the flight controllers initially dismissed the warning lights as a possible instrumentation glitch. But then the telemetry began to scream. Main Bus B voltage dropped to zero. Then Main Bus A followed. The fuel cells—the ship’s primary power source—began to fail one by one. The crew watched in disbelief as their primary supply of oxygen bled into space. Within two hours, both oxygen tanks were completely empty. Fate intervened just days before launch
It was meant to be the third lunar landing. A routine “mountain expedition” to the Fra Mauro highlands, a geologically rich area named after a 15th-century Italian monk. For the astronauts—James Lovell, Fred Haise, and Ken Mattingly—it was the culmination of years of relentless training. For the American public, weary of Vietnam War headlines and the gradual normalization of spaceflight, Apollo 13 was almost mundane. The networks had even ceased live coverage of the launch. But at 9:07 PM EST on April 11, 1970, the massive Saturn V rocket lifted off from Kennedy Space Center, carrying with it a crew and a spacecraft that would never touch the Moon, but would instead etch itself into history as NASA’s most harrowing and brilliant “successful failure.” The Crew: Experience and the Cruelty of a Measles Exposure The crew dynamics were critical to the survival that followed. Commander James A. Lovell Jr. was a space veteran, having flown on Gemini 7, Gemini 12, and Apollo 8—the first mission to orbit the Moon. For Lovell, Apollo 13 was deeply personal; it was his chance to finally walk on the lunar surface. Command Module Pilot (CMP) Thomas K. “Ken” Mattingly was the meticulous, brilliant navigator and systems expert. Lunar Module Pilot (LMP) Fred W. Haise Jr. was a former Marine Corps pilot and a civilian test pilot, making his first spaceflight. “Jack” Swigert Jr
Lovell would often say, “Apollo 13 wasn’t a failure. It was a triumph of the human spirit.” In the end, the mission did not land on the Moon. But it landed something far more profound in the collective memory: a reminder that in the cold, dark, infinite vacuum of space, the most powerful engine of all is the human mind, working together, duct-taping a square peg into a round hole to bring three men home.
Splashdown occurred within one nautical mile of the recovery ship, the USS Iwo Jima. The astronauts were weak, dehydrated, and suffering from hypothermia and urinary infections. But they were alive. The Apollo 13 Review Board concluded that the explosion was caused by a combination of poor design, inadequate testing, and a series of minor errors that cascaded into a catastrophe. The Teflon-insulated wires in the oxygen tank, the use of an incorrect thermostat, and the decision to use 65-volt ground support equipment on a 28-volt system—all were human errors.