Space Missions Codexery

Apollo 13

Seventh crewed Apollo mission; aborted after oxygen tank explosion.

Apollo 13

Apollo 13 launched on April 11, 1970, as the seventh crewed Apollo mission and the third planned Moon landing. Two days into the flight, an oxygen tank in the service module exploded, knocking out its electrical and life-support systems. The landing was called off. Using the Lunar Module’s backup systems, the crew swung around the Moon on a circumlunar path and splashed down safely in the South Pacific on April 17. Commander Jim Lovell, command module pilot Jack Swigert, and Lunar Module pilot Fred Haise made up the crew. Swigert had replaced Ken Mattingly at the last minute after Mattingly was exposed to rubella.

The explosion happened when a routine stir of an oxygen tank ignited damaged wire insulation inside it. Both of the service module’s oxygen tanks vented into space. Without oxygen for breathing and power generation, the service module’s propulsion and life support failed. The command module’s systems were shut down to save its resources for reentry, forcing the crew to move into the Lunar Module, which became their lifeboat. Mission Control in Houston improvised new procedures so the LM—built to support two men for two days—could keep three men alive for four days. The crew endured limited power, a cold, wet cabin, and a shortage of drinking water. They also had to adapt the command module’s carbon dioxide scrubber cartridges to work in the LM, a fix devised by the crew and ground teams. The danger briefly revived public interest in the Apollo program, and tens of millions watched the splashdown on TV.

An investigation found fault with preflight testing of the oxygen tank and the presence of Teflon inside it. Changes were made for Apollo 14, including reducing flammable materials in the tank. The story has been dramatized several times, most notably in the 1995 film *Apollo 13*, based on Jim Lovell’s 1994 memoir *Lost Moon*, and in a 1998 episode of *From the Earth to the Moon*.

President John F. Kennedy had challenged the U.S. in May 1961 to land a man on the Moon and return him safely by the decade’s end. NASA worked through Project Mercury, Project Gemini, and the Apollo program to meet that goal. Apollo 11 succeeded on July 20, 1969, with Neil Armstrong and Buzz Aldrin walking on the lunar surface while Michael Collins orbited in the command module. The mission returned on July 24, fulfilling Kennedy’s challenge. NASA had ordered fifteen Saturn V rockets; with Apollo 11 using the sixth, nine remained for up to ten landings. But public interest waned after Apollo 11, Congress cut NASA’s budget, and Apollo 20 was canceled. Astronauts could not get life insurance for the risky missions.

Planning for a centralized mission control facility began even before the first U.S. astronaut flew in 1961, largely driven by Christopher C. Kraft Jr., who became NASA’s first flight director. During John Glenn’s 1962 orbital flight, one of Kraft’s decisions was overruled by managers, but post-mission analysis proved him right. He then established that the flight director’s word was absolute during a mission—overruling him would require firing him on the spot. Apollo flight directors had a one-sentence job description: “The flight director may take any actions necessary for crew safety and mission success.” Houston’s Mission Control Center opened in 1965, designed in part by Kraft and later named for him. Each flight controller monitored telemetry and communicated with specialists in a Staff Support Room who focused on specific systems.

Apollo 13 was the second H-class mission, intended to demonstrate precise lunar landings and explore specific sites. With Apollo 11 having met Kennedy’s goal and Apollo 12 proving precision landing was possible, planners could emphasize science, especially geology. The mission’s motto was *Ex luna, scientia*—From the Moon, knowledge.

Commander Jim Lovell, 42, was a Naval Academy graduate, naval aviator, and test pilot. Selected in NASA’s second astronaut group in 1962, he flew Gemini 7 with Frank Borman in 1965, Gemini 12 with Buzz Aldrin in 1966, and Apollo 8 in 1968, the first mission to orbit the Moon. By Apollo 13, he had logged 572 hours in space, more than any other NASA astronaut. Jack Swigert was the command module pilot, and Fred Haise the Lunar Module pilot.

Mission
Apollo 13
Commander
Jim Lovell
Command Module Pilot
Jack Swigert
Lunar Module Pilot
Fred Haise
Program
Apollo space program

Lore & Background

The mission was commanded by Jim Lovell, with Jack Swigert as command module pilot and Fred Haise as Lunar Module pilot. Swigert was a late replacement for Ken Mattingly, who was grounded after exposure to rubella. A routine stir of an oxygen tank ignited damaged wire insulation inside it, causing an explosion that vented the contents of both of the SM's oxygen tanks to space. Without oxygen, needed for breathing and for generating electrical power, the SM's propulsion and life support systems could not operate. The CM's systems had to be shut down to conserve its remaining resources for reentry, forcing the crew to transfer to the LM as a lifeboat.

Reader's Guide

Apollo 13 is significant as a dramatic example of in-flight crisis management and improvisation. Although the LM was designed to support two men on the lunar surface for two days, Mission Control in Houston improvised new procedures so it could support three men for four days. The crew experienced great hardship, caused by limited power, a chilly and wet cabin and a shortage of drinking water. There was a critical need to adapt the CM's cartridges for the carbon dioxide scrubber system to work in the LM; the crew and mission controllers were successful in improvising a solution. The astronauts' peril briefly renewed public interest in the Apollo program; tens of millions watched the splashdown in the South Pacific Ocean on television. An investigative review board found fault with preflight testing of the oxygen tank and Teflon being placed inside it.

Did You Know?

The Crew and a Last-Minute Swap

Commander Jim Lovell brought a depth of experience to Apollo 13 that no one else in the program could match. Fred Haise, the thirty-six-year-old Lunar Module pilot, was a former Marine Corps fighter pilot and civilian research pilot for NASA. The crew's composition was not set in stone, however. Ken Mattingly had originally been scheduled as CMP, but a rubella exposure forced him to the ground, and Swigert stepped in at the last moment—a substitution that would prove consequential in the days that followed.

The Explosion and the Aborted Landing

Two days into the flight, a routine stirring of one of the service module's oxygen tanks triggered a catastrophic event: damaged wire insulation inside the tank ignited, and the resulting blast hurled the contents of both oxygen tanks out into the void. Oxygen was the lifeblood of the spacecraft—it was needed both for breathing and for generating the electrical power that kept everything running. With both tanks gone, the service module's propulsion and life-support systems were effectively dead. Mission controllers immediately ordered the command module's systems shut down to preserve whatever resources remained for the eventual reentry. The three astronauts were forced to abandon their primary vehicle and squeeze into the Lunar Module, a craft never intended to serve as a lifeboat, and begin a long circumlunar loop around the Moon to get home.

Four Days in a Two-Man Lifeboat

The Lunar Module had been engineered to sustain two astronauts on the lunar surface for roughly two days. Now it had to keep three men alive for four, with no margin for error. Mission Control in Houston scrambled to devise entirely new procedures for rationing power, managing consumables, and maintaining cabin conditions. The crew endured a cold, damp interior and a critically low supply of drinking water. Perhaps the most urgent engineering problem was the carbon dioxide scrubber: the command module used round cartridges, while the Lunar Module's system was built for a different shape. Crew members and controllers in the back rooms collaborated to fashion an adapter from available materials, and the improvised fix worked. The splashdown in the South Pacific on April 17 was witnessed by tens of millions of television viewers, a moment that briefly rekindled a public appetite for the space program that had been waning since the euphoria of Apollo 11.

Investigation, Reform, and the Story That Endured

Once the crew was safely recovered, a review board examined what had gone wrong. It concluded that preflight testing of the oxygen tank had been inadequate and identified Teflon material placed inside the tank as a contributing factor. The board urged that potentially combustible items be minimized within the tank's interior, a recommendation that was implemented before Apollo 14 flew. The broader context made the failure all the more poignant: after the triumph of Apollo 11, public enthusiasm had cooled, congressional budgets for NASA were shrinking, and Apollo 20 had already been canceled. The astronauts themselves were considered such high-risk workers that they could not secure life insurance to protect their families. Yet the drama of Apollo 13's near-disaster captured the nation's attention once more.

Frequently Asked Questions

What happened to Apollo 13 in space?

Roughly two days into the flight, an oxygen tank in the service module ruptured, which crippled the spacecraft's electrical power and life-support systems and forced the crew to abort the planned lunar landing.

Who were the astronauts on Apollo 13?

The three-person crew consisted of Commander Jim Lovell, Command Module Pilot Jack Swigert, and Lunar Module Pilot Fred Haise.

Why is Apollo 13 important to space history?

It is widely regarded as one of the greatest 'successful failures' in spaceflight, demonstrating how rapid problem-solving by both the flight crew and ground controllers can turn a catastrophic emergency into a safe return home.

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